Category The Apollo of aeronautics

AGEE Approval

On February 17. 1976, the 10 members of the Senate Committee on Aeronautical and Space Sciences published its report on the “Aircraft Fuel Efficiency Program.” Frank Moss and Barry Goldwater, the Senators who wrote the original letter to the NASA Administrator about the need for a conservation solution to the aviation fuel crisis a year earlier, led the Committee. NASA’s six-part response, coupled with broad support from industry, made a compelling case for funding the $670-million program, in the Committee’s opinion.

The Moss and Goldwater Senate Committee published several conclu­sions regarding the hearings. Its members stated first that they had learned that fuel efficiency would play a cutting edge role in competing in the world aircraft market. Second, they believed that embarking on a fuel- efficiency program would serve as an important stimulus to the U. S. air­craft industry. The benefits would accrue not only to the traditional aircraft manufacturers and operators, but also to the numerous subcontractors. In 1974, more than half a million people were employed in the aircraft and parts industry. Third, new fuel-efficient aircraft would offer a major assist­ance to the entire air transportation system, which was struggling for prof­itability and survival in the midst of a fuel crisis and escalating oil prices. Although the technologies identified by NASA would not have an imme­diate impact. Moss and Goldwater concluded that “higher fuel costs will remain an urgent program in the foreseeable future… more fuel efficient aircraft will be highly desirable and beneficial to the air transportation system in the next and succeeding decades.”[84]

Fourth, the Committee stressed that the project was important because it involved energy conservation. With the potential to reduce fuel con­sumption by up to 50 percent, its effects would include higher profits and more environmentally friendly technology, which included aircraft noise and pollution reduction. By using less fuel, the market demand for oil would also decrease. Basic economics suggested that a reduction in demand would decrease prices, providing yet another way for airlines to increase profitability. Finally, in an area that was unquantifiable, yet perhaps undeniably the most important of all, the NASA program would strengthen the United States. Decreasing demand for fuel would “reduce the vulnerability of the… Nation to the whims of oil rich nations.”54 The technology could also be adapted by the military, with the Air Force incor­porating fuel-efficient technology to increase the range of its bombers.

One other major conclusion of Moss and Goldwater’s report was that it was the Government’s responsibility to bear the risk and the costs of the technological research and development. There were several reasons for this. First, the Senators acknowledged the “considerable risk” associ­ated with the projects. With the cost to develop a new airplane already at SI billion. Moss and Goldwater said, “it is no mystery why aircraft manufacturers must be conservative in their choice of their technology."[85] [86] [87] Even if industry were to try to develop it. the technology would be propri­etary, and the benefit to the Nation would be significantly reduced. So the Senators concluded that the aircraft fuel-efficiency program was a “classic example” of the need for Government support.

NASA was the appropriate Government Agency to take the lead, thanks to what the Senators recognized as its “long history of excellence.” Although NASA had recently become associated with space explo­ration, they pointed out that “aeronautics is a part of the very name of the agency.”47 Also, very clearly, NASA was not in business to build air­planes—so though it would take the lead in the research, it would also determine the most opportune time to transfer the technology to industry.

Moss and Goldwater carefully took into consideration the criticisms of the program, most specifically those of the Federal Energy Administration. In addressing the first argument, that no one really knew how much fuel savings these program would create, the Senators responded that this was precisely the reason for the research project in the first place —so that NASA could determine w hich projects were feasible. As for whether the airlines would not have the capital to purchase the new technological effi­cient airplanes in 1985. the Senators were confident that the aging air trans­portation system, which would be ready for replacement with some type of aircraft, would offer a fuel-efficient solution to the problem Why would airlines executives purchase the older, less-fuel-efficient aircraft? As to the third argument, the question was: Why focus on aircraft when automobiles consumed so much more fuel? The Senators responded to concerns about the program’s focus on aircraft over automobiles by explaining that no automotive fuel conservation program was being proposed, and that the airline fuel-efficiency program should be judged on its own merits.

The Senators agreed that it was impossible to predict the real indus­try costs for implementing this advanced technology, recognizing that the proposed program’s only established costs were the amounts required for NASA’s research. On the other hand, they argued that there was no indication that the costs would be prohibitive, and the fact that there was broad approval from industry supported this assumption. In rejecting the notion that all costs should be established up front, the Senators wrote, “We believe it would be a mistake to insist that all the costs (or benefits) must be assessed before a decision on the program can be made.” They justified being lax in their demands for financial analysis because of their unquestioned belief in the importance of the fuel-efficient technology. Furthermore, it is almost impossible to perform a cost-benefit analysis on basic research. On this point, they simply responded, “We feel this program has the potential of returning enormous benefits, far in excess of the costs.”

In conclusion, the Senators approved the NASA plan. “On the basis of fuel savings alone,” they wrote, “the aircraft fuel efficiency program is attractive. And considering all the potential benefits and NASA’s man­date to maintain U. S. leadership in aeronautics, the program is essential.”5* With its mandate in place. NASA immediately went to work to put the plan into action and divided responsibility for the six technology initia­tives between two NASA Centers. It would fall upon the shoulders of Lewis Research Center in Ohio and Langley Research Center in Virginia to make these technological dreams a reality.

Threads and Sails. at Langley

Threads and Sails. at Langleyeveral revolutionary advances in aircraft design and technology

emerged from NASA’s Langley Research Center in the 1970s as a result of the Aircraft Energy Efficiency program. Historian Roger Bilstein referred to them as “arcane subjects” that included “some unusual hard­ware development The first of them challenged the seemingly obvious assumption that the aircraft should be made of metal and aluminum. Most people took for granted that these were the best aircraft materials until a 1978 Los Angeles Tunes reporter speculated that “Large commercial and military jets of the future will probably be made not of metal but of thread.”[88] [89] [90] Machines with “gigantic spools of yarn” began making airplane parts with “threads” from new composite materials that promised tremen­dous weight savings, thereby making airplanes more fuel efficient.1

Another Langley development fundamentally changed the shape of the aircraft in two key ways. The first idea was an airplane wing that emulated a boat “sail" through a change in its shape at the wingtip. These first became visible in the 1980s, when the main wings on some aircraft, including the MD-11 in 1986. took an unusual upward or vertical extension at the end of the wing. This acted like a sail, taking advantage of a whirlpool of air that naturally occurred around the wingtip. The sail caught the swirling air. trans­formed it into forward thrust, reduced drag, and increased fuel efficiency.[91]

A second development, called the “supercritical wing,” was so unusual that when it emerged from a Langley wind tunnel, even its designer con­fessed, “nobody’s going to touch it with a ten-foot pole without somebody going out and flying it.”[92]

These striking new technological developments —threaded aircraft materials, wing “sails,” and supercritical wings—were the primary focus of two ACEE projects led by Langley engineers. They were airframe tech­nology advances with the primary goals of reducing structural weight and improving aerody namic efficiency as a means of decreasing fuel consump­tion.[93] The threaded aircraft materials were part of the Composite Primary Aircraft Structures (CPAS) program. The sailboat emulation, officially known as a “winglet,” and the supercritical wing were two of the most successful components of the multifaceted Energy Efficient Transport (EET) program. A central portion of Langley’s contribution to the ACEE program, these projects achieved significant savings in fuel economy.[94] [95]

The Flying Field—Langley Research Center

In his autobiographical novel, Look Homeward, Angel. Thomas Wolfe described summer 1918, when, as a young man, he went looking for work in 1 lampton, VA. There. at a place called the “Flying Field.” he observed gangs of workers engaged in “grading, leveling, blasting from the spongy earth the ragged stumps of trees and filling interminably, ceaselessly, like the weary and fruitless labor of a nightmare, the marshy earth-craters, which drank their shoveled toil without end.”1′

The Flying Field—Langley Research Center

Langley Memorial Aeronautical Laboratory in the 1920s. One enduring feature was the mud around the administration building. (NASA Langley Research Center (NASA LaRC].)

Wolfe’s evocative prose spoke of the human muscle required to con­struct a facility devoted to escaping the bounds of Earth. What these men achieved was the construction of the only American civilian aviation labo­ratory until 1941. The laboratory became the first Center of the newly cre­ated National Advisory Committee for Aeronautics (NACA).

The “Flying Field” was named for aviation pioneer Samuel P. Langley, a Harvard University professor of astronomy and Secretary of the Smithsonian Institution.

In the 1890s, he became obsessed with flying aircraft, but his unusual “aerodrome” experiments resulted in spectacular crashes, and the press began referring to his machines as “Langley’s folly.”4

He died in 1906. having never flown, but his namesake laboratory would become one of the leading centers of aeronautical research in the world. The NACA charter of 1915 defined a very specific mission: to “super­vise and direct the scientific study of the problems of flight with a view to their practical solution.” This practical emphasis meant that Langley’s [96]

The Flying Field—Langley Research Center

Samuel Pierpont Langley < 1834-1906) and Charles M. Manley, left, chief mechanic and pilot onboard the houseboat that served to launch Langley ‘s aerodrome aircraft over the Potomac River in 1903. (NASA Langley Research Center [NASA LaRC|.)

The Flying Field—Langley Research Center

The Langley aerodrome (December 8.1903). After this photo was taken, the project ended in failure when it fell into the Potomac River. (NASA Langley Research Center |NASA LaRQ.)

engineers would treat aeronautical problems not from a theoretical distance, but through the reality of actual aircraft in flight. More than any other American institution, it was responsible for the research necessary to solve the problems of flight and develop the airplane into both a commer­cial product and a centerpiece of the Nation’s defense.[97] [98] Commissioned in 1920, its early years were filled with both promise and hardship. Langley’s three original buildings included a wind tunnel, an engine-dynamometer laboratory, and a research laboratory that became what some described as an “aeronautical mecca” in the United States."

The earliest aeronautical work at Langley included the construction and use of experimental wind tunnels, the first in 1920, to test new aircraft designs. Because the wooden biplanes of the 1920s were so frail, engineers

The Flying Field—Langley Research Center

Langley Laboratory’s first wind tunnel, a replica of a 10-year-old British design, became operational in June 1920. (NASA Headquarters —Greatest Images of NASA |NASA HQ GRIN).)

had a tremendous opportunity to improve aerodynamic efficiency through their research. They first began asking questions about how the shape of wings would decrease drag, how to design propellers, when to best use flaps, and how to predict control forces on various aircraft components.

Langley’s engineers developed the world’s first full-scale research tun­nel for propellers in 1926, and its work in drag reduction and retractable landing gear were among some of its first major technical breakthroughs. The engineers also developed the “NACA cowling.” which covered the engine, significantly reduced drag, and improved engine cooling. While all these advances required fundamental research, the ultimate goal was the practical application.

Practical achievements continued for the next several decades. In the 1930s, Langley’s laboratory tests contributed to the development of advanced aircraft such as the Douglas DC-3 and the Boeing B-17. During World War II, Langley’s engineers worked to improve the performance capabilities of military aircraft. In 1944, the NACA was in the process of testing 78 different types of aircraft, and a vast majority of these tests were done at Langley. But by this time, Langley was no longer the NACA’s only Center. The NACA established Ames Research Center in California to complement Langley in 1940. One year later, the NACA opened Lewis Research Center in Cleveland. OH. to focus on engine propulsion. After the war. Langley’s engineers explored the unknown areas of supersonic flight with jet aircraft (the ’“X” series of experimental aircraft) as well as vertical take-off and landing helicopters. But times were changing. Langley was no longer the sole NACA Center, and the American aeronautical landscape was a much different place.

After World War 1, the NACA had a clear-cut vision: improve American aeronautics. After World War II, it struggled to find its way. During the war, jet propulsion emerged, and many hoped that the NACA and Langley would take the lead in probing the frontiers of this new revo­lution in flight. But the NACA now had competition. The U. S. Air Force had grow n to become a branch of the military, with equal status to the Army, Navy, and Marines, and it began conducting its own aeronauti­cal research and development. At the same time, aircraft-manufacturing became the largest industry in the United States. Not only was it also capable of its own research, but it depleted some of the NACA’s talent pool by luring the best young aeronautical engineers with far better paying positions than the NACA could afford. This powder and research potential gave industry a much stronger voice in dictating the direction and pace of research. The NACA needed to stake out its own sphere of influence in the postwar world, but its aging engineers were increasingly responding to the demands of the United States aircraft industry.[99] [100]

The NACA needed revitalization, but this was not to be. Alex Roland described the 1950s as a time when the NACA seemed to be “waiting for the match.” Other historians, including Virginia Dawson and James Hansen, have demonstrated that the NACA was still making contributions in the 1950s, among them axial compressors and supersonics, but in many respects, as Dawson suggested,“The difference was that the air force was nowr calling the shots.”1-‘ Hansen also described the 1950s as an important time of transition in aeronautics. I le wrote, “As the golden age of atmospheric flight reached full maturity in the 1950s — with only a few major things (like super­sonic transport) left undone —many [engineers] . . . moved successfully from their mature aeronautical specialties into the new ones of spaceflight and reentry.”[101] [102]

As Roland characterized it. in 1957 Sputnik “provided the spark that set it off and… soon the old agency was consumed in flames.”1′

Although NASA, with an emphasis on space, replaced the NACA in 1958, aeronautics remained an important component of the new Agency, and aviation research continued at Langley.[103] But aviation was no longer an “infant technology.” The NACA had achieved much, and the military and industry were also engaging in their own research and building their own test facilities. So aeronautics in the newly formed NASA often took a back seat to the more visible successes of the Apollo program. It main­tained some of its greatest practical aviation importance and vitality, how­ever, through service to the aircraft industry, which still needed the support that only Government could provide in leading-edge technology. This was best exemplified by the ACEE project, and Langley took a leading role.

By the 1970s, the aircraft industry in the United States was extremely important to the economic health of the Nation, and it made up a signifi­cant percentage of its positive balance of trade, second only to agriculture. International sales of American-manufactured aircraft from 1970 to 1975 totaled $21 billion. Robert Leonard. Langley’s ACEE Project Manager, said that the export of a single jumbo jet equaled the importation of 9.000 automobiles.[104] [105] However, this dominance was not assured. In 1978. Ralph Muraca, Langley’s Deputy ACEE Project Manager, said there was a “real threat” to United States’ dominance after other nations began develop­ing new, efficient planes. Muraca concluded, “Clearly the importance of capture of most of this large market segment by our industry cannot be underestimated.”"1 Just because the United States held onto this mar­ket in the mid-1970s did not mean its dominance would last. This was especially true if it failed to develop fuel-efficient aircraft. As the price of jet fuel increased, fuel-efficient aircraft became move coveted throughout the world. Craig Covault, from Aviation Week <£ Space Technology, sim­ply referred to this as ‘“the challenge."

One key challenger was Airbus. Airbus began in the mid-1960s as a consortium of European aviation firms, and its mission was to compete directly with the American-dominated industry. In 1967, the first A300 appeared —a 320-seat, twin-engine airliner. In the late 1970s, Langley managers used a picture of a new French Airbus draped in Eastern Air Lines colors to illustrate the European threat. Donald Hearth, the Langley Director, said that because of this competition, his Center would begin restricting the flow of research results derived from the ACEE program to Europe. He said. “It is going to present an awkward situation and a change in the way we operate, and I’m not quite sure what it all means yet."[106] One thing wfas certain —ACEE was the most vital aeronautics program in the United States. Not only did it shoulder the burden and expectation of free­ing the airline industry from the effects of the energy crisis, but the ACEE programs became the chief strategic hope to ensure American-made dom­inance of next-generation aircraft in the world’s skies. The importance of ACEE, Leonard said, “cannot be overstated."[107] One of the more vital ACEE initiatives was research focusing on the materials used in the manu­facture of airplanes, which probed the potential not for stronger or less expensive materials, but lighter ones.

A Strategic Center of Gravity—Composite Materials for Aircraft

Since the beginning of aviation history, weight reduction has been a primary goal.[108] During the time of the Wright brothers’ first flights, air­planes were constructed of various types of wood, fabric, and wires.[109] It w’as not until the 1920s that one of the first materials breakthroughs occurred, the Ford Tri-motor, dubbed the “Tin Goose.” Henry Ford began manufac­turing these aircraft in 1925, and they were unusual because of their use of metal and aluminum. The first planes used a corrugated metal shell, which surrounded a metal truss framework. In the 1930s, stressed-skin aluminum monocoque construction techniques emerged, and Langley played a key role in developing stress and strength analyses of the mate­rials. These analyses paved the way for other structural and materials advances at Langley, which included thin wings for military aircraft in the 1940s. The new aircraft were required to withstand the stresses resulting from much faster speeds and also greater dynamic loads and vibrations. Langley engineers helped to pioneer the use of higher-strength alloys that prevented the aircraft from breaking apart under these forces. In the 1960s, a new type of material emerged that would come to challenge the domi­nance of metals in the skies. These were known as composites.

In 1967, at the 50th anniversary of the birth of the Langley laboratory, engineers announced that they were on the verge of several revolutionary new aircraft concepts, one of which was in materials.2′ The size of aircraft hadin – creased dramatically since the time of the first airplanes. The Wright broth­ers’ historic first aircraft was a fragile device that weighed just 1,260 pounds. In comparison, the all-metal 747 aircraft, which first flew 1 year after this Langley celebration, weighed 750,(XX) pounds. The fuel required to lift and propel these massive, metallic beasts was immense, so any weight reduction achieved through new materials was eagerly anticipated. Langley engineers believed they were on the cusp of achieving a major advance in composites.[110] [111]

When two or more substances are combined together in one struc­ture, the resulting material is called a composite. Aircraft composites are made by bonding together a primary material that has strong fibers with an adhesive, such as a polymer resin or matrix. These are various types of graphite, glass, or other synthetic materials that can be bonded together in a polymer epoxy matrix. The composite materials are typically thin-thread cloth layers or flat tapes that can lie shaped into complex and

A Strategic Center of Gravity—Composite Materials for Aircraft

The corrugated shell is made from thermoplastic composite materials (February 17. 1978). (NASA Langley Research Center |NASA LaRC|.)

aerodynamically smooth shapes of virtually any size.2′ Their application to aircraft led some to imagine the “Jet Fighter Made of Thread The physi­cal properties of these materials made them extremely attractive in aircraft design because they were stronger, stiffer, and lighter than their metallic counterparts. Composites were also resistant to corrosion, a constant plague on metal aircraft. While efforts to incorporate these materials had been ongoing for several years prior to the 1970s, there were difficult hur­dles that prevented their adoption. First was the general uncertainty as to whether they would actually work and could withstand the rigors of flight. The second was the cost of research and development simply to reach the stage at which they could be flight-tested. The cost of fabrication for pro­duction applications was, and still is, a key factor. Finally, there were no [112] [113] data on their durability and maintenance requirements over time. As one observer stated, “The planned application of composites would require the development of revolutionary technology in aircraft structures.”[114]

This development became the focus of 1972 joint Air Force – NASA program known as Long Range Planning Study for Composites (RECAST). The success of these investigations led NASA to include it as one of the six main program elements of ACEE, and it became known as the Composite Primary Aircraft Structures. Langley Research Center was to coordinate the program in conjunction with its industry partners: Boeing Commercial Airplane, Douglas Aircraft, and Lockheed. Langley was the obvious choice for this program, because the Center had played a lead­ing role for decades in investigating aircraft structures and materials. The stated objective of CPAS was to “provide the technology and confidence for commercial transport manufacturers to commit to production of compos­ites in future aircraft.”-[115] The technology included the development of design concepts and the establishment of cost-efficient manufacturing processes. The confidence would come with proof of the composite s durability, cost verification, FAA certification, and ultimately its acceptance by the airlines.

The main goal was to reduce the weight of aircraft by 25 percent through the use of these new materials, thereby decreasing fuel usage by 10 to 15 percent. Using composites for the wings and fuselage promised the greatest savings, but this was also the most technically challenging because these components were so vital to aircraft safety. To overcome some of the uncer­tainties of the materials, secondary structures (upper aft rudders, inboard aileron, and elevators) were the first candidates for composite materials.

Once these investigations were successful, then the development of medium-size primary structures (vertical stabilizer, vertical fin, horizontal stabilizer) would begin. In the meantime, some preliminary wing work would be explored, followed by work on the fuselage. Louis F. Vosteen headed the program at Langley.[116]

A Strategic Center of Gravity—Composite Materials for Aircraft

Composite elevators in flight evaluations on Boeing 727 during ACEE program. Courtesy of Joseph Chambers.

Secondary structures are those that have light loads and are not critical to the safety of the aircraft. The upper aft rudder on the Douglas DC-10 was one of the first of the secondary structures to be studied.3" The rudder is a mov­able vertical surface on the rear of the vertical tail and is used for coordinating turning maneuvers and trimming the aircraft following the loss of an engine. Work to construct composite upper aft rudders actually began in 1974 but was completed as part of the ACEE program. Twelve units were put into sen ice, and ACEE engineers estimated that manufacturing would cost less than metal after 50 to 100 units were installed. These units resulted in a 26.4-percent weight savings over the traditional aluminum alloy previously used for the rudder. Elevators were the next secondary structural components designed. Located at the rear of the fixed horizontal surfaces, elevators are movable sur­faces used for controlling the longitudinal attitude of the airplane. Ten units were designed for the Boeing 727, and flight-testing began in March 1980." [117] [118]

A Strategic Center of Gravity—Composite Materials for Aircraft

Composites technology was applied to other projects as well. The Rutan Model 33 VariEze was built by the Model and Composites Section of Langley and then tested in a tunnel. (July 17. 1981). (NASA Headquarters-Greatest Images of NASA (NASA HQ GRIN].)

With a 23.6-percent decrease in the plane’s weight, Boeing considered the production a success and approved the elevators for use on the 757 and 767. The final secondary structures were the inboard ailerons, move – able surfaces located on the edges of the wing/2 Working in conjunction [119]

A Strategic Center of Gravity—Composite Materials for Aircraft

NASA’s Boeing 737 in front of the hangar after its arrival in July 1973. Much ACEE work was performed on the 737 in later years. (NASA Langley Research Center [NASA LaRC|.)

with the rudder, in-board ailerons are used for banking the airplane during high-speed turning maneuvers. Installed on a Lockheed L-1011 airplane, eight units began flight-testing in 1982. These were a significant improve­ment over the aluminum ailerons, reducing the weight by 65 pounds, the number of ribs from 18 to 10. and the number of fasteners from 5.253 to 2,564.” Taken together, these 3 secondary structures made with graph­ite epoxy materials weighed 1.500 pounds and represented a 450-pound weight reduction over the aluminum components.54

Three other medium primary structures were designed for the ACEE program: the vertical fin. the horizontal stabilizer, and vertical stabilizer. The “medium primary" classification meant that other components were attached to them (and they provided the aircraft with stability), so they were more critical to a safe flight than the secondary structures were. The vertical fin is at the rear of the airplane, where it contributes aerodynamic directional stability.

Design of a composite vertical fin for the Lockheed L-10I1 started in 1975, and the project was then transferred to the ACEE program once [120] [121] underway in 1976.15 The development was plagued by several problems when the composite materials failed prior to reaching ultimate load, and as a result, it never progressed beyond the static testing stage under ACEE. Though it never took flight, this was a 7-foot by 23-foot structure and, at 780 pounds, represented a 22.6-percent weight savings. The next medium primary structure designed was the horizontal stabilizer. This is a fixed surface at the rear of the airplane that provides longitudinal sta­bility.*6 Designed for a Boeing 737, it too experienced structural failures during ground tests, but these were corrected, and the FAA certified the component in August 1982. On April 11. 1984. the first composite primary structure went into service, representing 28.4-percent weight savings.[122] [123] [124] [125] [126] The final medium primary structure was the vertical stabilizer. Located at the back of the airplane, it is used to control yaw, or the rotation of the vertical axis.3*1 Designed for the Douglas DC-10, the vertical stabi­lizer provided a 22.1-percent reduction in weight, but it too experienced several production problems and failed a ground test. After the failure, engineers incorporated a different structure, and though it took much more time to develop than expected, the FAA certified it in 1986. and commer­cial flight commenced in January 1987.’9

Langley engineers wrote a number of computer programs to aid in the design and analysis of these composites. PASCO analyzed compos­ite panels and helped determine their material strength. V1PASA provided data on buckling and vibration and worked in conjunction with PASCO. CONMIN was a nonlinear mathematical programming technique that assisted in sizing issues.4’* Three years later, another program, POSTOP, assisted in the design of composite panels by analyzing compression, shear, and pressure on the materials.[127] [128] Temperature effects were also included. Other design and analysis studies used traditional mathematics and experi­mentation. Extensive failure studies were undertaken to help ensure the durability of the composite structures. One type of study analyzed what happened when surfaces cracked and how that compromised the safety of the airplane.[129] Resulting experiments looked at repair techniques for these composite structures when cracks and other tears appeared.[130]’

Engineers also designed long-term environmental studies to deter­mine the possible effects of environmental exposure on the composites. One concern was that the composites would degrade over time because of ultraviolet light. Another concern was whether they would absorb moisture. Tests included composite panels placed on airport rooftops at Langley and in San Diego, Seattle. Sao Paulo, and Frankfurt. These took into account geographical location, solar heating effects, ultraviolet deg­radation. and test temperatures.[131] Other studies evaluated components in flight. Richard A. Pride, who headed the program at Langley, found that after 3 years, “No significant degradation has been observed in residual strength.”[132] Longer-term studies, up to 10 years, indicated that composites did not degrade over time given normal use and environmental exposure.[133]

Despite the success of these studies, there was one important envi­ronmental concern that threatened to halt the composites program and for a time did ground all composite flight-testing. Because carbon libers were a main component of these composites, flight over population centers was an environmental issue. The risk was to everyday electrical systems that could potentially be damaged through exposure to the accidental release of carbon fibers into the air through an accident or crash. There was a possibility that libers released from composite aircraft materials could interfere with electri­cal systems on the ground (because the libers can conduct electricity), caus­ing them to fail. The concern spanned from the mundane—a toaster or televi­sion—to the critical—air traffic control equipment or nuclear powerplants. The fibers were so light that they could be easily blown and distributed in the air by an explosion, affecting a wide area. Moderate winds could spread them tens of miles. The airline industry was concerned because it would then be liable for replacing all the failed electronics equipment.[134] A major ACEE investigation, the Carbon Fiber Risk Assessment, was launched to determine the significance of this threat.[135]* It was headed at Langley by Robert J. I luston, the Program Manager of the Graphite Fibers Risk Analysis Program Office.

After extensive research at Langley, engineers concluded that the threat would be negligible.[136] [137] For example. 0.00339 televisions out of 100 would fail. Only 0.(X) 171 toasters would be affected out of 100. For more critical equipment, the predictions were also low, only 0.005 out of 100 types of air traffic control equipment, or 0.016 out of 100 ground computer installations. After more than 50 technical reports, NASA predicted that carbon fiber accidents would only cause SI,000 worth of damage in 1993, and the absolute worst-case scenario would be a $178,000 loss occurring every 34,000 exposures.4′ Compared with other possible air transportation threats, the carbon fiber risk was simply nonexistent.

While the ACEE composites program lasted 10 years, from 1976 to 1985, it ended before achieving its major goal of developing wings and fuselages with composite materials, the stated goal of the program, because the wing and fuselage represented 75 percent of the weight of the airplane. Wings and fuselages made of composites would have achieved signifi­cant weight savings and fuel economy.[138] [139] [140] There were several reasons that these were never developed by ACEE. First was the amount of time and resources devoted to the Carbon Fiber Risk Assessment. Unanticipated at the start of the project, this potential problem became a serious threat to the use of composites. Therefore, it was necessary to prove that there was little risk in their use. After this setback. NASA was finally able to devote all of its attention to wings and fuselages in 1981, but engineers took a dif­ferent approach to their development than they did with the previous com­ponents. Whereas before NASA had developed composites that replaced entire metal components on aircraft, it now decided to try to incorporate composite pieces into the fuselage (a section barrel) and wing (short-span wing box). Boeing studied the damage tolerance of composite wings, the threat posed by lightning strikes, and an evaluation of their fuel sealing capabilities.5’ Lockheed examined acoustic issues, such as how noise was transmitted through flat, angular, composite panels and how to reduce it/" By this time, the ACEE program and its funding were nearly at its end, so the ultimate goal of composite wings and fuselages was never attained.[141]

Nevertheless, the success ACEE had with secondary components was called “almost revolutionary.” One observer said this 10-year period represented the “golden age of composites research in the United States.”[142] ACEE became a “strategic center of gravity” in this golden age, and its achievements in secondary structures were vitally important in introducing a new type of material as an alternative to the traditional metal and aluminum used in airplanes. The Composite Primary Aircraft Structures program had several very significant results over its lifespan.[143] It produced 600 technical reports and provided a cost estimate for develop­ing these materials and a confidence in their durability and long-term use. Composites received certification by the FAA. as well as general accept­ance by the airline industry. Overall, its estimated that the ACEE program was responsible for accelerating the use of composites in the airline indus­try by at least 5 to 10 years. Langley continued to track the composites it developed even after the ACEE program concluded, and 350 composites reached 5.3-million flight-hours in 1991 and were still operational.

According to Herman Rediess, one of the initial ACEE task force mem­bers. “Many of things that we were talking about at the time are now just so standard that people hardly even remember that they came out of ACEE.” Prior to the ACEE program, aircraft manufacturers were reluctant to investigate the opportunities these composites offered because of costs and unknown performance capabilities. But, as Rediess now reflects. “It’s a major, major aspect of our commercial transports. It has really paid off in terms of weight savings, and in that weight is fuel.”[144] [145] [146] By the 1990s, these composite materials resulted in a fuel efficiency savings of 15 percent.54 As one observer concluded at a 1990 conference on composite materials, “The NASA Aircraft Efficiency Program provided aircraft manufacturers, the FAA, and the airlines with the experience and confidence needed for extensive use of composites in… future aircraft.”50

Since the end of the ACEE program, the use of composites has increased, though not as dramatically as first imagined. While the weight savings and fuel efficiency were undeniable, their mass implementa­tion was offset by the cost of producing them, compared with metal and

A Strategic Center of Gravity—Composite Materials for Aircraft

This X-29 research aircraft in flight over California’s Mojave Desert shows its striking forward – swept wing and canard design. The X-29 demonstrated the use of advanced composites in aircraft construction. Two X-29 aircraft flew at the Ames-Dryden Right Research Facility from 1984 to 1992. (NASA Dryden Flight Research Center Photo Collection.)

aluminum structures. They are also more expensive to certify for flight readiness.[147] As fuel costs increase in the 21st century, however, the economic returns for lighter aircraft will become more valuable, and composites will take on greater significance. Today, the military has sur­passed commercial aviation in the use of composites. For example, com­posites account for 38 percent of the weight of an F-22 but only 10 per­cent of a Boeing 777, which has the highest composite percentage of any commercial aircraft.[148]

The new Boeing 787 Dreamliner may become the first major com­mercial aircraft with composites comprising the majority of its materials, as the company is planning for 50 percent of primary structures, including


A Strategic Center of Gravity—Composite Materials for Aircraft
A Strategic Center of Gravity—Composite Materials for Aircraft
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A Strategic Center of Gravity—Composite Materials for Aircraft

A Strategic Center of Gravity—Composite Materials for AircraftFixed upper l. e. skin panels

A Strategic Center of Gravity—Composite Materials for Aircraft

The above graphic demonstrates the composite components of the Boeing 767. Courtesy of Joseph Chambers.

The above graphic demonstrates the composite components of the Boeing 777. Courtesy of Joseph Chambers.

A Strategic Center of Gravity—Composite Materials for Aircraft

Composite aircraft Laneair Columbia and Cirrus SR20. Courtesy of Joseph Chambers.

fuselage and wing, to be composites/’- The general aviation community has also benefited from composites. For example, small personal-owner aircraft and homebuilt aircraft, with designer Burt Rutan taking the lead, have taken advantage of composites technology. Business-class aircraft such as Beech Aircraft (now Raytheon Aircraft Company) has developed an all-composite aircraft known as the Laneair Columbia 3(X) and the Cirrus SR20.

The ACEE composites program was a success because, according to Jeffrey Ethell, it “demolished the fear factor surrounding the new mate­rials, which have entered the real world of transport aviation.”6′ ACEE served as an encouraging point of departure for industry entering the world of composites. The program took materials that were untested, unusual, and exotic, and it transformed them into certified and usable structures on commercial and military aircraft. According to Joseph Chambers, "The legacy of the ACEE Program and its significant contributions to the [149] [150] acceleration, acceptance, and application of advanced composites has become a well-known example of the value of Langley contributions to civil aviation. In the best tradition of NASA and industry cooperation and mutual interest, fundamental technology concepts were conceived, matured, and efficiently transferred to industry in a timely and profes­sional manner/4"1

Advanced Aerodynamics—Energy Efficient Transport

Another important ACEE airframe technology program was one Langley engineers Robert W. Leonard and Richard D. Wagner called a “somewhat arbitrarily termed ‘Energy Efficient Transport/”6* Like the composites program, this ACEE project was also to be managed by Langley, and it promised to be of great importance to industry. Unlike the composites pro­gram. whose objective was to focus on a single technology development that promised significant fuel savings, the Energy Efficient Transport proj­ect planned to achieve fuel efficiency through a number of aerodynamics advances. These included the following areas of research: supercritical wings, winglets, nacelle aerodynamic and inertial loads, wing and tail sur­face coatings, laminar flow control, and active controls. NASA’s Langley Research Center partnered with Boeing Commercial Airplane, Douglas Aircraft, and Lockheed-Califomia to analyze, design, test, and assess these advanced aerodynamic concepts.[151] [152] [153]

Most commercial airplanes fly at what is known as transonic speeds. This is an aeronautics term for velocities just below and above the speed of sound (Mach 0.8 to 1.2). “The transonic regime,” as Roger Bilstein said, “had beguiled aerodynamicists for years." Despite being the speed of choice for modern aircraft, those cruise speeds present numerous aero­dynamic challenges.[154] At these speeds, both subsonic (less than the speed

Advanced Aerodynamics—Energy Efficient Transport

Lockheed L-1011 EET model used in testing of the Energy Efficient Transport project at Langley Research Center (January 5.1982). (NASA Ames Research Center |NASA ARC].)

of sound) and supersonic (more than the speed of sound) airflow patterns exist over the aircraft simultaneously, so even if an airplane is flying at subsonic speeds, airflow over certain sections of the wing might reach supersonic levels, forming strong shock waves on the upper surfaces of the wings and resulting in a dramatic increase in drag. This problem is known as the “sound barrier." As one observer said, “The barrier was con­quered (in 19471 with brute force, but the trick now is to subdue it qui­etly and efficiently."6* Solving the challenge, known as the “supercritical" Mach number, was an important problem.64 Engineers knew that if they could solve it. they would significantly improve cruise performance and increase fuel efficiency. It was to this task that Langley engineer Richard Whitcomb first applied himself in the 1960s. After several years of [155] [156]

Advanced Aerodynamics—Energy Efficient Transport

Richard Whitcomb looks over a model of the Chance Vought F-8 aircraft incorporating his supercritical wing (July 1.1970). (NASA Langley Research Center (NASA LaRC].)

research and extensive wind tunnel studies, he redesigned the wing shape with a flatter upper surface, which reduced the strength of shock waves. A dow nward sloping curve at the wing’s trailing edge increased the lift. Because the supercritical w ing could be thicker than a conventional wing, the aspect ratio of the wing could be increased to reduce the drag, and the wing sweep could be decreased for more efficient cruise. The “supercriti­cal w ing” was born. In 1972. after 12 test flights. Whitcomb said. “I feel confident we’ve reached a milestone in the program.”[157]

To take advantage of Whitcomb’s work. NASA needed an incentive to perform further flight tests and incorporate it into a commercial transport that would be both aerodynamically and structurally sound. This incentive came with the fuel crisis, and the supercritical w ing became part of the EET project. Langley engineers began generating a database of w’ing vari­ables in wind tunnels that tested the various effects of thickness, camber

Advanced Aerodynamics—Energy Efficient Transport

NASA selected a Vought F-8A Crusader as the testbed for an experimental supercritical wing. (January 1.1972). (NASA Dryden Flight Research Center [NASA DFRC] Photo Collection.)

(the wing’s curvature), sweep, and aspect ratio (a measure of the wing’s ratio of span to area). The results of their research led to the adoption of this wing in a variety of aircraft. Industry followed Whitcomb’s lead with its own supercritical wing designs. Boeing incorporated a version of the wing in the Boeing 767 in 1981 and the Boeing 777 in 1995. James Hansen has called the 777’s wing the “most aerodynamically efficient airfoil ever developed for subsonic commercial aviation.”’1 The wing’s success can be traced directly back to the pioneering work performed by Whitcomb and the ACEE engineers.

The supercritical wing was not Whitcomb’s only inspiration. In 1974, he developed a new idea, known as winglets. While the supercritical wing promised fuel efficiency in the future when new aircraft were built, the winglets were important because they could be immediately retrofitted.

Looking and acting like a vertical sail, they took advantage of the swirling vortex of airflow around the tip of the wing. Whitcomb published [158] the results of his study in July 1976 and promised a 4- to 8-percent drag reduction. He confidently predicted, “Just as sure as the sun rises, the next new commercial transport aircraft will have winglets.”[159] Since the whirlpool of air around the wingtip was different for every airplane, it was left to the aircraft manufactures to design and test specific winglets for their planes. To encourage their adoption, NASA and the EET pro­gram cosponsored industry flight tests on aircraft. The first, between 1978 and 1979. included research with Douglas Aircraft on its DC-10. The suc­cess in reducing fuel consumption was quickly apparent: Robert Leonard. Langley’s ACEE Project Manager, said. “Frankly, the winglet looks very promising on the DC-10.”” Douglas designers incorporated winglets into their new MD-11 development in 1986.[160] [161] [162] Very quickly, the entire industry realized the importance of the winglet.[163]

Other issues caused by structural reinforcement for flutter and gust loads required solutions.6 One approach to providing structural weight reduction while maintaining safety margins was a computer-assisted advance called Active Controls Technology (ACT), also known as a Control-Configured Vehicle (CCV). While ACT technology had been investigated prior to ACEE, this program served to increase dramatically confidence and industry acceptance. The ACT system used an onboard computer system to control surfaces on the trailing edges of the wings and on the tail sections of the aircraft. The computer acted independently from the pilot, working to minimize the aircraft’s structural loads when it encountered turbulence or making a tight turn while maintaining a suffi­cient flutter margin. To achieve this, sensors on the surfaces of the aircraft sent feedback to the computer, which in turn could send compensating signals to the control surface actuators. Computers, not pilots, were best suited to handle these controls because turbulence is a random, time-

Advanced Aerodynamics—Energy Efficient Transport

А КС-135 with winglets in flight over the San Gabriel Mountains, south of Edwards. (January 1.1979). (NASA Dryden Flight Research Center [NASA DFRC| Photo Collection.)

dependent phenomenon, and the electronic system can react much faster than a human pilot can. The sensors and the computer were able to com­municate to rudders, elevators, and ailerons within a split second to adjust correctly for these disturbances.[164] [165] Hindering the development of such a system were a lack of confidence that the design was possible and a belief that they were not cost effective. Langley engineers worked with counter­parts at Douglas, Lockheed. and Boeing to solve these problems and install active controls on several types of specific airplanes. The results of these studies proved that an ACT airplane required an investment of $600,000, with a 25-percent return on investment (based on fuel prices in the early 1980s). The FA A also concluded that they were flightworthy, and that no single failure in the system would result in the loss of control of the aircraft. Pan American World Airways purchased the first aircraft with active controls (L-1011-500) and then began to retrofit active controls to all planes of this type in its fleet.’* Another important aerodynamics advance explored under the EET program focused on airframe/propulsion integration. The main effort in this area was the Nacelle Aerodynamic and Inertial Loads (NAIL) program directed jointly by Langley and Lewis Research Center. Engineers knew that the most critical period of deterioration for aircraft engine efficiency occurs during the initial period of its life. After the engine reaches approxi­mately 1,000 flights, this deterioration levels off substantially. The goal of the NAIL program was to provide as much data as possible on the early life of a jet engine to determine the causes for the decreases in efficiency. The Centers partnered with Boeing and Pratt & Whitney, and a NAIL engine was constructed, flown, and then disassembled and inspected. The test flights revealed that the highest “flight loads,” or wear, occurred at low speeds, high angles of attack, and high engine airflow, conditions most typ­ically occurring at takeoff.74 The conclusions served as the basis for future nacelle redesigns that would have a greater ability to withstand flight-load wear and tear, specifically during these periods of flight.

There were two areas of the EET program that overlapped with other ongoing ACEE investigations at Langley. Much like the composites pro­gram. the Aircraft Surface Coatings program explored the use of new mate­rials that would improve the surface smoothness of aircraft. The Apollo spacecraft had used Kapton. a film polyimide, as a coating, which reduced drag, decreased maintenance, and offered increased protection. Similar advantages were sought for aircraft surfaces. Langley engineers identified elastomeric polyurethane coatings such as CAAPCO and Chemglaze and tested them on a Continental Airlines Boeing 727 used by Air Micronesia. Micronesia was selected because of its high rainfall environment, which typically degrades surface coatings. The engineers found that these mate­rials produced a small decrease in drag and at the same time increased pro­tection from corrosion.1“ One question the EET program left unanswered was whether the polyurethane would work equally well to reduce drag on larger winglike surfaces with curvatures.

A second EET program with similarities to another ACEE program was laminar flow (see chapter 5 for a complete description of laminar flow). EET engineers performed natural laminar flow studies that resulted in some [166] [167] successes. When analyzed, a 757 achieved a significant natural laminar flow, improving fuel efficiency on a Mach 0.8 flight over 2,400 miles.[168]

The EET programs—supercritical wings, winglets, nacelle aero­dynamic and inertial loads, wing and tail surface coatings, laminar flow control, and active controls—were successful in reaching the goals of the ACEE program. EET was the focus of nearly 150 technical reports, which serve as a comprehensive database describing the new ideas that were evaluated and proved viable. These reports expressed an overall confi­dence that EET would result in the production of new airplanes that would attain at least 15 to 20 percent more fuel efficiency than those currently in production[169] Of these. James Kramer, who initially headed the ACEE Committee, said “the major visible EET results" of this program were the winglets, supercritical wings, and the active control technologies. The advanced aerodynamics investigations of ACEE were a success.®[170]

Ironically, some of these fuel-saving technologies diffused more quickly among European nations. In the early 1980s, Richard Wagner, a Langley ACEE manager, said he was flying a French-made Airbus A310 to Israel and, to his great surprise, when he looked out his window while the plane was still on the tarmac, on the tip of the wing he saw a winglet. It was actually the Israelis who were the first to apply winglets on the Westwind. Although they had been in use on smaller business jets in the United States, this was the first time Wagner had seen winglets on a com­mercial transport, where the winglets had their greatest advantage. Wagner concluded with some remorse, “So it seems like the Europeans, in my own personal observation, may have capitalized more upon the ACEE program results than our own American companies.”[171]

A further concern that Langley managers articulated at the start of the ACEE program was the threat to American dominance of aircraft manufacturing on the world stage. By 1982, Eastern Air Lines had pur­chased 34 Airbus A300 transports. This moved Airbus into second place internationally in terms of aircraft manufacturing, putting it ahead of the American Douglas and Lockheed companies. The international challenge was growing, but because the Energy Efficient Transport and the com­posites program were already showing important fuel-efficiency returns, many believed the United States would remain competitive despite the growing challenge from Airbus and European governmental support. Robert Leonard, of Langley, believed one major reason was that “fuel efficiency will continue to dominate purchase decisions by the world’s airlines”81 Assisting in this effort were the NASA engineers at Lewis Research Center in Cleveland, OIL who focused on innovative propulsion project to further improve fuel efficiency. [172]

Ld and New. Engines at Lewis


an American World Airways was for a time the most influential airline organization and known quite simply as the airline that “taught the world to fly”1 Begun in the late 1920s through a legendary partnership between Juan Trippe and Charles Lindbergh, it sought to pro­mote international commercial air transport in the United States. It was widely successful and through the early 1970s led the world in the com­mercial transport industry. Because of the increasing price of oil, however, the United State’s largest airline suffered a major setback in 1973, and the company was driven to the edge of bankruptcy in 19743 L. H. Allen, its vice president and chief engineer, said that when “fuel prices for Pan Am. .. reached a staggering 40 cents per gallon,” fuel efficiency then ranked as the “single most important factor in aircraft operations today.”[173] [174] [175] Allen tried to offset these devastating forces by working with NASA’s Lewis Research Center and its Aircraft Energy Efficiency (ACEE) program to devise new ways to make aircraft engines more efficient.

Like the Langley Research Center, NASA’s Lewis Research Center in Cleveland, OH. operated its own specialty fuel-efficiency research programs under ACEE. The first of these propulsion projects. Engine Component Improvement (ECI)—with Pan Am serving as one of its chief

Lewie Research Center NASA


Ld and New. Engines at Lewis

The three ACEE projects at Lewis Research Center. (NASA Glenn Research Center [NASA GRCJ.)

independent evaluators and main program supporter—focused on improv­ing existing turbofan engines through the redesign of selected engine com­ponents that were most prone to wear.[176] An attempt to “cure sick engines,” it was the least technically challenging of the three Lewis ACEE projects and aimed for a 5-percent improvement in fuel efficiency. The second project, the Energy Efficient Engine (E3), involved building “a brand new engine from scratch” and offered a far greater payoff—a 10- to 15-percent increase in fuel efficiency.[177] These two engine projects became Lewis’s most significant contribution to improving fuel efficiency for the Nation’s commercial aircraft. (A third Lewis project, the Advanced Turboprop, the most controversial of all, will be addressed in a later chapter.)

While Pan Am’s collaboration on ACEE was successful, it was not enough to save the company, which declared bankruptcy in January 1991.

Ld and New. Engines at Lewis

Langley engineers ai the Structural Research Laboratory designing the NACA’s new engine lab in Cleveland. Among those pictured are: Addison Rothrock. George Darchuck, Harold Friedman (at the front and center with his back to the camera), and Nick Nahigyan (across table from Friedman) (April 21.1941). (NASA Glenn Research Center [NASAGRC].)

The reason most often cited for its demise, according to historian William Leary, is that it was never able to recover from the ‘’the world oil crisis.”[178]

From Engines to Energy—Lewis Research Center

Established during World War II as an aircraft engine research laboratory, Lewis became the third laboratory of the National Advisory Committee for Aeronautics, following Langley and Ames.

From Engines to Energy—Lewis Research Center

Bruce Luiulin in 1960 at the Rocket Laboratory. Lundin investigated heat transfer and worked to improve the performance of World War II aircraft engines. From 1969 to 1977. he was Director of the Lewis Research Center. (NASA Glenn Research Center (NASA GRC|.)

Lewis engineers pursued aircraft engine research in the national interest —often over the objections of the engine companies, who per­ceived the Government as interfering w ith the normal forces of supply and demand. During the early years of the Cold War. the laboratory participated in engine research and testing to assist the engine companies in developing the turbojet engine. After the launch of Sputnik, the laboratory focused on a new national priority—rocket propulsion research and development. All work on air-breathing engines ceased for nearly 10 years. The return to air­craft engine research coincided with drastic reductions in staff, mandated by cuts in NASA’s large-scale space programs. The mass exodus of nearly 800 personnel in 1972 sparked an effort to redefine the Center’s mission and find new sources of funding. One year later, the Nixon Administration reduced the NASA budget by $200 million. This coincided with OPEC’s oil embargo and galvanized the Center’s Director, Bruce Lundin, to look for ways to use its propulsion expertise to help solve the energy crisis* [179] [180]

From Engines to Energy—Lewis Research Center

Lewis Research Center in 1968. (NASA Glenn Research Center (NASA GRC|.)

Lewis engineers were exploring a variety of alternative energy pro­grams, and Virginia Dawson characterized its new focus as “Lewis turns earthward.” These efforts began in the early 1970s with the NASA Volunteer Air Conservation Committee, headed by Louis Rosenblum and J. Stuart Fordyce. They were inspired by the tragic symbol of a polluted Cleveland, which became a national joke after the literal burning of its Cuyahoga River. Then Robert Hibbard began a graduate seminar with stu­dents from area universities, which focused on ways to develop cleaner engines and other environmental issues.4 In 1971, Lewis established its Environmental Research Office, set up monitoring stations throughout the city, and worked with the Environmental Protection Agency (EPA) to study water pollution in Lake Erie. In the early 1970s, Lewis engi­neers also initiated research using its nuclear test reactor at Plum Brook Station, irradiating over 1,000 samples per year for the EPA.[181] [182] According to Dawson, emerging from these programs “were the seeds from which an

From Engines to Energy—Lewis Research Center

Windmill project conducted by Lewis Research Center (September 3. 1975). (NASA Glenn Research Center (NASA GRCJ.)

entirely new effort would grow”[183] These efforts were soon followed by investigations into alternative energy sources—wind, solar, and electric.

In 1974, Lewis received SI.5 million for a wind-energy program from the National Science Foundation and the Energy Research and Development Administration (ERDA). As a result, the Lewis-managed Plum Brook Station eventually built experimental windmills for research. With 2 massive 62-foot propeller blades, the first 125-foot windmill was capable of generating 100 kilowatts. At the time, it was the second largest windmill ever constructed in the United States. One engineer who worked on the Lewis windmills predicted that the country would soon see "hun­dreds of thousands of windmills generating electricity across the United States.”[184] The most impressive of those built by Lewis engineers w’as a commercial wind turbine generator in Hawaii in 1988. which was then the world’s largest.[185]

A program in solar cell technology development followed on the windmill project’s heels, along with increasing funding for various energy-related programs by ERDA and its successor, the Department of Energy.[186] Though Lewis lost out on a bid for a $35-million Federal solar research institute, its growing expertise in alternative energy was becom­ing well known. In 1978, Lewis’s engineers were consulted in building the world’s first solar-power system for a community —the 96 residents of the Papago Indian village about 100 miles northwest of Tucson. Louis Rosenblum designed the solar array and helped install it. His system replaced the Papago tribe’s kerosene lighting in 16 homes, a church, and a tribal feast house.[187] [188]

The creation of an electric automobile was another Lewis project. Known as the Hybrid Vehicle Project, its engineers researched several experimental concepts to achieve increased fuel efficiency and decreased emissions and address a growing national need caused by its energy depen­dence.1,1 These primarily electric vehicles were charged by an outside source. Lewis engineers completed their initial plan in 1975 and entered discussions with ERDA about how and when to begin research. One Washington Post article speculated that the Center’s work “could make electric vehicles practical and reduce U. S. dependence on foreign oil.”[189]

From Engines to Energy—Lewis Research Center

Electric urban vehicle at Lewis Research Center. (NASA Glenn Research Center (NASA GRC(.)

The changing focus of the Center’s activities prompted rumors— emphatically denied—that it would become part of the ERDA. This even resulted in one report that asked “Should the Agency Continue an Aeronautical Propulsion Program at Lewis?”[190] [191] The Lewis engineers responded by unionizing, and in December 1974, instead of joining the American Federation of Government Employees, they created the new Engineers and Scientists Association and became part of the International Federation of Professional and Technical Engineers. They also looked for a way to return to the roots and the expertise of the Center—engine research. They found their major new mission in the growing national need to develop more efficient engines for commercial aircraft. The new emphasis on energy-efficient aircraft, unlike the ERDA projects, promised to keep Lewis firmly in NASA’s fold.14 Moreover, it brought high visibil­ity to the aeronautics side of NASA, long overshadow ed by the enormous budgets and prestige of the space program.

From 1973 to 1976, according to Donald Nored. the head of the Lewis ACEE programs, “there was much action at Lewis, at Headquarters, and within the propulsion industry addressing fuel conservation,”[192] Preliminary studies explored technology concepts that improved efficiency. At the time, Nored remembered, a strong national need fostered a climate that was favor­able and aggressive in its support of research. Concepts, ideas, and programs were plentiful, but Nored explained that the genesis of many of the origi­nal ideas was blurred because of the frequent interaction and “synergism in the activities.” Nonetheless, the period from 1973 to 1976 demonstrates the early articulation of ideas that eventually led to Lewis’s three main proj­ects in the ACEE program—Advanced Turboprops, a new energy-efficient engine, and engine performance improvements and deterioration studies.

National need prompted Lewis engineers to begin their fuel efficiency studies 3 years before ACEE’s inception. In April 1973.6 months before the OPEC oil embargo, the Energy Trends and Alternative Fuels study began at NASA Headquarters, with Lewis and Ames assisting. The goal was to iden­tify alternative fuel studies and project fuel usage requirements in the future. Abe Silverstein, Lewis’s former powerful Director, chaired the Alternative Aircraft Fuels Committee. By the end of the year, discussions centered on recommending programs more specifically for aircraft fuel conservation and conventional and unconventional modifications to aircraft engines.

In January 1974, a steering committee performed design studies, explored new fuel-conservation technologies, and suggested modifica­tion to existing engines. Its work concluded I month later, with a plan to establish an Energy-Conservative Aircraft Propulsion Technology pro­gram. an ambitious, 9-year plan, accompanied by a funding request of SI36 million. By April of that year, cost-benefit analyses were presented to Headquarters. A main component of the project was a new energy-effi­cient engine, which some speculated would be 30 percent more efficient than existing engines and could possibly be ready for service by 1985. This project eventually evolved into the Energy Efficient Engine program.

The Advanced Turboprop had its origins in an American Institute of Aeronautics and Astronautics (AIAA) workshop in March 1974. After much discussion, the participants agreed that a 15-percent fuel savings was possible. The Engine Component Improvement program traced its beginnings to summer 1974, when Lewis engineers awarded a contract to American Airlines, allowing them to examine the airlines’ records to begin looking at how its JT8D and JT3D engines deteriorated over time. These records provided early clues as to the extent and cause of the performance decline of the engines. Pratt & Whitney also entered into a contract with Lewis to investigate similar issues and in January 1975 offered its findings on performance deterioration for its current engines. It was at this time that the Kramer Committee took the lead in coordinating NASA’s efforts in air­craft fuel conservation, working to establish one central program to orga­nize these activities. Kramer, according to Nored, was “very successful in guidance of the program. . . through the various Headquarters/OMB/ industry advisory board pitfalls that can squelch a new start.’”1 The ACEE program was underway, and Lewis engineers were anxious and enthusias­tic about their three aircraft propulsion projects.

Curing Sick Engines—Engine Component Improvement

It was Raymond Colladay’s responsibility to establish the three ACEE propulsion projects at Lewis Research Center. Having started his career at Lewis in 1969. he moved to NASA Headquarters in 1979 to become the Deputy Associate Administrator of the Office of Aeronautics and Space Technology, and then head of DARPA in 1985. Colladay recalled that, at the time he was helping to develop the ACEE program, it was an easy sell to Congress. “The general tenor of Congress and the country as a whole was focused on energy efficiency.” and “therefore the Congress was pretty receptive to NASA trying to do what it could in research for energy effi­ciency." The biggest hurdle was the Office of Management and Budget (OMB). Ideologically, its concern was the proper role of Government in a research and development enterprise. The OMB did not want NASA developing applications for the aircraft industry. While this was not a problem for the majority of the ACEE programs, Colladay said, “the area that caused them the greatest concern was the ECI program because it was component improvements in existing engines, existing aircraft engines.”[193] [194]

Curing Sick Engines—Engine Component Improvement

Three of the engines studied in the Engine Component Improvement (ECI) project. The EC1 engineers’ mission was to improve various components on existing engines that were most likely to wear and decrease fuel efficiency. (NASA Glenn Research Center [NASA GRC].)

The Engine Component Improvement project was unique among all the ACEE programs in that it was expected to return quick results. While other projects looked to incorporate fuel savings advances over 10 to 15 years, ECI aimed to incorporate new technologies within 5 years. The project did not call for revolutionary advances or fundamental changes to existing airplanes. Instead, the mission of the ECI engineers was to improve the components on existing engines that were most likely to wear and decrease fuel efficiency. Pratt & Whitney Aircraft and General Electric manufactured most of the commercial aircraft engines in the United States in the 1970s, and both of these companies collaborated closely with Lewis Research Center on the ACEE project. According to the ECI statement of work, written in December 1976. the main objectives of the program were to “(1) develop performance improvement and retention concepts which will be incorporated into new production of the existing engines by the 1980-1982 time period and which would have a fuel savings goal of 5 percent over the life of these engines, and (2) to provide additional technology which can be used to minimize the performance degradation of current and future engines."25

In 1976, four jet engines that were responsible for powering all com­mercial aviation in the United States. These engines consumed 10-billion gallons of fuel per year.-4 The ECI project focused specifically on devel­oping fuel-saving techniques for the JT9D, JT8D, and CF6 engines. It ignored the JT3D. the fourth major engine, because most industry ana­lysts believed it would not be produced in the future. Introduced in 1964, the Pratt & Whitney JT8D engine was a “phenomenal success” and at its height of popularity flew 12.000 aircraft of different types.25 Two years later, Pratt & Whitney introduced the JT9D engine, often referred to as opening a “new era in commercial aviation ” because it was the first high-bypass engine to power a wide-body aircraft. It was first installed on the Boeing 747 Jumbo Jet. and Pan American placed the first order for this new jet in April 1966.26 The CF6, a General Electric engine first introduced in 1971, was used on the DC-10 and became the cornerstone of its wide-body engine business for more than 30 years.

The organizations involved in the ECI program read like a who’s who of the airlines industry in America at the time. Beginning in February 1977, NASA awarded the two major contracts to General Electric and Pratt & Whitney.27 Because these companies stood to increase their sales significantly thanks to these NASA advances, a cost recoupment clause was included in their contracts. They were to pay to the U. S. Treasury a 10-percent return on every sale of one of these improved engine compo­nents. which was how the ACEE administrators persuaded the OMB to let [195] [196] [197] [198] [199]

Curing Sick Engines—Engine Component Improvement

Pan Am-Boeing 747 flying in 1975. It was one of the main types of aircraft used to test and incorporate ACEE fuel-saving technology. (NASA Glenn Research Center [NASA GRC).)

them go ahead with the ECI project. Every engine that went into active service and had a component traceable to ECI triggered this recoupment. Colladay recalled, ‘’It was a bigger headache than any money it derived, and NASA never saw the money anyway, it went into the Treasury."211

General Electric and Pratt & Whitney then established subcontracts with American Airlines. Trans World Airlines, United Airlines. Douglas Aircraft, and Boeing. In addition. Lew is Research Center also contracted with Pan American (for an international route analysis) and Eastern Airlines (for domestic analysis of the technology ) to review’ the program independently and provide ongoing assessments for 30 months.[200] [201] All of these contracts called for three specific tasks: feasibility analysis, development and evalu­ation in ground test facilities, and in-service and flight-testing. According to Colladay, the reason for the inclusion of essentially all the major airlines

in the United States was to “generate a broad base of support” and ensure the highest probability that the ECI technology would be rapidly retrolitted into existing engines or incorporated into new engine builds.10

Although getting this broad base of support was important, it did generate some problems—most notably in the relationship between General Electric and Pratt & Whitney. Though within the ECI program they worked together with NASA, in the real world. General Electric and Pratt & Whitney were fierce competitors. Theirs was a historic rivalry. After World War II. Pratt & Whitney dominated in the commercial air­craft engine market, while General Electric was more closely aligned with the military. However, their spheres of influence shifted over time, and by 1977, Pratt & Whitney began losing ground to General Electric in the commercial market. This set the stage, in the early 1980s, for what some have called the "great engine war” between the two companies.4

Because of this, the collaboration was sometimes difficult. Pratt & Whitney thought there were “major problem areas” with their relationship. Nored. head of the NASA Energy Conservative Engines Office, admitted that the office was having “extreme difficulty" with Pratt & Whitney and said. “I think they are suffering a corporate reaction to the increasing com­petition by GE (JT9D vs. CF6).” Both of these engines were scheduled to be improved within ECI. Nored thought the company was nervous about the Freedom of Information Act and as a result wanted to classify all of its research as proprietary. Pratt & Whitney also, in his opinion, sought more and more governmental support to “augment their technology in ways that can influence immediate sales.” In accepting this assistance, the company had to learn how to work in the much more open governmental research atmosphere, and sometimes this included being bedmates with chief rivals. For example, General Electric had expressed no concerns about sharing pro­prietary information, and Nored concluded that Pratt & Whitney needed to “bite the bullet.”’- The program continued despite its often-stated concerns. [202] [203] [204]

There were two main thrusts to EC1 —Performance Improvement and Engine Diagnostics. The Performance Improvement section began with a feasibility study to examine a variety of concepts and to prove which one might offer the highest fuel-savings results for the airlines industry. The study looked at the development of an analytical procedure to deter­mine possible concepts, the identification and categorization of concepts, preliminary concept screening, and detailed concept screening. Engineers evaluated 95 concepts for the Pratt & Whitney engines and another 58 concepts for the General Electric engine. The job of the airline industry was to "assess the desirability and practicality of each concept."3′ The con­cepts were evaluated on two main criteria—technical and economic fac­tors. Technical factors included performance, weight, maintenance, fuel – savings potential, material compatibility, development time, and technical risk, while economic factors included fuel prices, engine cost, production levels, operating costs, return on investment, and life expectancy. Using these criteria, the 153 initial concepts were quickly reduced to 18 and 29, respectively. They were then reviewed in greater detail by NASA and the airlines, which identified 16 concepts that could meet their goals.

The content of these projects can be broken into several important areas. The first was leak reduction. An aircraft engine is similar to an air pump in that it moves air from in front of it to the back. By adding energy to it, the speed of the air moving through the exhaust is faster than what originally came through the inlet. Any air leak in this system caused it to be inefficient, just like an air pump leak. ECI engineers looked for areas in which engine seals could be improved to reduce this leakage. A second major area for improvement was in aerodynamics: ECI engineers devel­oped improved designs of the compressor and turbines. A third area was ceramic coatings on components, which was important because it reduced the necessity of cooling holes and both increased efficiency and reduced manufacturing costs.

Specifically, the 16 projects, and their related engine types, were as follows. For the JT8D. they included an improved high-pressure turbine air seal, high-pressure turbine blade, and a trenched tip high-pressure compressor. JT9D improvements for the high-pressure turbine included a [205] ceramic outer seal, a thermal barrier coating, active clearance control, and new fan technology. CF6 improvements were a new fan, a front mount for the engine, a short core exhaust nozzle, improved aerodynamics for the high-pressure turbine, a roundness control for the turbine, and active clear­ance controls for the turbine. There were two other aircraft-related proj­ects: a nacelle drag reduction for the DC-9 and compressor bleed reduction for the DC-10. The ECI Performance Improvement program was signifi­cant thanks to its success after only a few’ years of research, testing, and development. According to Jeffrey Ethell,“By 1982 most of the improved components were flying and saving fuel, giving the companies involved a firm leg up in the commercial aircraft marketplace, w here they were being challenged by foreign competition."14

The Engine Diagnostics program focused on analyzing and testing the JT9D and CF6 engines.[206] [207] [208] Pan Am engineers considered this to be the “most significant work” of the ECI program. An often-used logo for the Engine Diagnostics program was an engine with a human face, frowning, tongue sticking out. and arms clasped over its midsection. A country doc­tor hunched over it, tools sticking out of his pockets, examining an x-ray machine, diagnosing a w ay to “cure the sick engine.” While just a carica­ture, it did simplistically convey the fundamental goals of this program. The engine “illnesses” were the performance losses they experienced as their flight hours increased. The “doctors” were the Lewis engineers, whose job was to determine the mechanical sources of these problems and recommend ways to “cure" the sick machines. Their recommendations could keep existing engines healthy and help to prevent the deterioration of future engines.3*

One known problem with these or any type of engines wfas that over time, various components begin to deteriorate because of operational stresses, which included combustors that w’arped because of continual fluctuation in temperatures from hot to cold, compressor blades whose tips w’ore down over time, seals that began to leak hot gases, and turbine blades eroding from high temperatures. Other types of damage could occur when foreign objects such as stones or dust entered the engines on the runway and caused dents, breaks, or scratches to the fan blades. The engines were durable and could typically tty for 10.000 hours before they needed major maintenance, but during that time, the engine slowly became less and less fuel efficient because of small degradations that did not compromise the safety of the aircraft. Furthermore, the major maintenance sessions never restored the engines to their original levels of fuel efficiency. Pan American engineers said that prior to the ECI Engine Diagnostics program, “engine deterioration had been largely a matter of educated guessing, speculation, and hand-waving.”” This deterioration became the focus of the Engine Diagnostics program, and engineers estimated that by preventing these wear-and-tear issues, aircraft would become more fuel efficient.

Engine Diagnostics engineers from NASA, General Electric, and Pratt & Whitney began their work by evaluating the existing data on perfor­mance deterioration from the airline industry and engine manufacturers. The data included in-flight recordings, ground-test data, and information on how frequently various parts were repaired and replaced. Additional data, needed on the JT9D and CF6. were obtained though special monitor­ing devices, as well as analysis gained from a complete teardown and eval­uation of the engines. Special ground tests were developed to experiment with short – and long-term performance deterioration. These ground tests helped engineers simulate operating conditions to determine the sources of component deterioration. From the data they collected, they identified certain components whose failure rates could be improved upon/1*

One concern, raised by Pratt & Whitney, was that the deterioration information on its engines was being used by its competitors. Its company slogan was “Dependable Engines," and extensive publications as to how they deteriorated over time was. in its opinion, damaging to its reputation; [209] [210] [211]

Specifically, the company had evidence that Rolls-Royce, a British engine competitor, used the ECI deterioration data from the JT9D and CF6 engines in its then-current marketing campaign, demonstrating the superiority of Rolls-Royce engines. A 1979 letter from Pratt & Whitney’s legal team to NASA expressed concerns that the ECI program would “adversely affect" its marketing and future sales potential. The team wanted NASA to change its dissemination policy for technical reports to protect the Pratt & Whitney “marketing position" for its engines.[212] NASA responded that this was an unintended consequence of the ECI program and the effort to improve engines for the United States airlines industry. Furthermore, according to NASA, Pratt & Whitney’s role in the program had been voluntary and had the “full backing and support of P&W management.” NASA officials had informed the companies at the outset that comparisons between the engines would be made, and both Pratt & Whitney and General Electric “realized the consequences of enter­ing into the program and accepted them.”[213]

The independent outside evaluations by Pan American and Eastern Airlines were an important part of the ECI project. The independent reports by Pan American World Airways are especially revealing. The reports were based upon 10 meetings held during the project in which NASA, General Electric, and Pratt & Whitney representatives summa­rized their work for the Pan America review committee. The first meet­ing, held at John F. Kennedy Airport in March 1977, was a get-acquainted session for the various participants to discuss early concepts, directions, and goals for the project.[214] By the sixth meeting, in September 1978, Pan American was expressing serious concerns, characterizing the program as “disappointing" and criticizing the ECI engineers for taking a “very con­servative approach," rather than a “considerably more aggressive" one. “We are also greatly concerned that the manufacturers appear to be losing sight of the basic objective of this program," Pan American concluded at the time.[215] By the end of the program. Pan American engineers saw significant areas of improvement and at one of the final reviews offered substantial praise to the program, saying, “In spite of what may have been interpreted as high critical comments during various review presentations”the pro­gram has resulted in “important knowledge” and was “quite successful.”[216] In fact, the ECI project was one of the more successful of the ACEE programs, for several reasons. The first reason was the speed with which improvements were incorporated onto commercial aircraft —many of the projects findings found their way into commercial aircraft engines before other ACEE programs even had their first test flights. John E. McAulay, the head of the ECI Performance Improvement project, presented the posi­tive results of the project’s work at the January 1980 Aerospace Sciences Meeting, just 3 years after the program began. While it “has already provided significant potential for reductions in the fuel consumed by the commercial air transport fleet,” he said he was optimistic that even greater savings were possible through their ongoing studies.[217] By March 1980. the ECI engineers had produced 20 technical papers, 21 contractor reports. 4 technical memo­randums, 6 conference publications, and 8 journal and magazine articles.[218]* Second, the organizations that benefited most from the project were very enthusiastic about the results when ECI ended. In 1980. Harry C. Stonecipher (General Electric vice president and general manger) wrote to John McCarthy (Director of Lewis Research Center) to highlight the program’s value to his company, writing that it generated a “wealth of knowledge” and that its main beneficiaries were the airline industry. He estimated the savings of this “invaluable” research at a reduction of 10 gallons of fuel for the CF6 engine for each hour of flight. Stonecipher concluded, “We at General Electric want you to be aware of the benefits this program has provided, and the tremendous potential for the years ahead.”[219]

Third, the ECI program helped to maintain the competitive advan­tage of the entire commercial aircraft industry. For example, in February 1980, Boeing executives approached NASA to ask if they could disclose results of the ECI program to foreign airlines, because in order to sell new American aircraft in the international marketplace, the company needed to show its more advanced understanding of engine deterioration and how to improve engine performance. NASA agreed with Boeing’s request and stated. “In order to meet the challenge presented by interna­tional competition, it is appropriate that the U. S. aircraft industry use the technology generated in the ECI program to maintain its dominant posi­tion in the marketplace.”4*As Roger Bilstein wrote, “Research results were so positive and so rapidly adaptable that new airliners in the early 1980s like the Boeing 767 and McDonnell Douglas MD-80 series used engines that incorporated many such innovations.”[220] [221] [222] Though the fuel-efficiency rewards were never intended to be as high as in other ACEE programs (including the Energy Efficient Engine), ECI was successful in achieving a significant fuel reduction of roughly 5 percent, exactly what its engineers projected at the onset of the program.

The Frontiers of Engine Technology — The Energy Efficient Engine

In the early 1980s. the aircraft industry had endured numerous difficulties, including reduced profitability, increasing fuel costs, higher worker wages, political pressures with deregulation, and increasing worldwide competi­tion. Many once-dominant airlines were fighting for their survival, includ­ing Pan Am. Pratt & Whitney and General Electric, two of the leading U. S. engine manufacturers, were “cutting each others’ throats, and prices,” and experiencing increasing difficulties competing in the world market against the British government-owned Rolls-Royce.30 But according to one 1983 report, despite these problems, the “airline industry in the years ahead

The Frontiers of Engine Technology — The Energy Efficient Engine

Model of the E* technology improvements. These included improved component aerodynamics, improved compressor loading, active clearance control, low emissions combustor, and higher-temperature materials. (NASA Glenn Research Center |NASAGRC].)

looks a bit rosier.” One major reason cited for this optimism was a “less noticed effort” that involved the redesign of the aircraft engine itself.[223] [224] This was another ACEE project managed by Lewis Research Center, known as the Energy Efficient Engine. As Forbes magazine reported, EJ was a "NASA success story.. . thoroughly overshadowed by the glamor­ous space programs.”’2

Given their intense competition. Pratt & Whitney and General Electric were strange bedfellows, but they continued this relationship in the Ei project. Each organization had ideas about how to improve fuel efficiency for aircraft engines, but neither was willing to accept the risk, in both time and money, to develop these ideas on its own. NASA stepped in to assume the majority of the risk, providing $90 million to each company, with a promise that each would invest $10 million of its own. This program had

The Frontiers of Engine Technology — The Energy Efficient Engine

GE Energy Efficient Engine (June 16.1983). (NASA Glenn Research Center |NASAGRC|.)

several main goals: to reduce fuel consumption by 12 percent, decrease operating costs by 5 percent, meet FAA noise regulations, and conform to proposed EPA emission standards. Additional goals included guidelines for minimum takeoff thrust and a safe and rugged engine with a 10-percent weight reduction.5′ The engines used for benchmarking fuel efficiency were the same ones used for the ECI studies—the Pratt & Whitney JT9D and the General Electric CF6. Also as in the ECI program, these two prime contractors worked with the airlines to discuss engine design options. These included Boeing. Douglas, and Lockheed. Eastern Airlines and Pan American served as additional advisers and contributed opera­tional experience.

The program was managed by Carl Ciepluch at Lewis (as well as Raymond Colladay for a time), Ray Bucy at General Electric, and W. B. Gardner at Pratt & Whitney. Bucy was extremely enthusiastic about this program, saying that the E’ program was “guiding the future of aircraft engines.”[225] [226] Fuel-efficient aircraft were very complex technological sys­tems that required extensive and costly research, he believed, but the rewards would be well worth the investment. Bucy hoped the resulting engine would save 1-million gallons of fuel per year for each aircraft fly­ing commercially. Gardner even thought that the program would surpass its expectations “beyond the program goal.”[227] [228]

That goal was to have a new turbofan engine ready for commercial use by the late 1980s or early 1990s. A turbojet derived its power and thrust entirely from the combustion and exhaust of its burning fuel.5* A turbofan is also a turbojet, but it has an extra set of rotating, propeller-like blades, positioned ahead of the engine core. The air from the fan goes partly through the engine core, and the remainder flows around the out­side the engine. The “bypass ratio” is the ratio of air flowing around the engine to the air flow ing through it. When this ratio is either 4 or 5 to 1. the engine is referred to as a “high-bypass engine.” The high-bypass turbofans were more efficient than were either the turbojets or the earlier low-bypass engines developed in the 1950s and 1960s. However, by the 1970s. the high-bypass engines promised greater potential for application to wide – body commercial aircraft, although one of their main problems was their environmental impact, in terms of noise and emissions.” The potential of the high-bypass turbofan engine was the Ei program’s main goal.

The idea for incorporating high-bypass engines into the existing com­mercial airline fleet began in 1974. Two investigations—the “Study of Turbofan Engines Designed for Low Energy Consumption." led by General Electric, and the “Study of Unconventional Aircraft Engines Designed for Low Energy Consumption," led by Pratt & Whitney—demonstrated a great deal of promise. Both studies suggested to NASA the importance of new high-bypass engines. But, as was so often the case, “the cost of such pro­grams. . . [was] enormous,” and the time required to accomplish it was at least a decade.5*1 To make the development more feasible for industry’, the report suggested a continued joint effort led by NASA, with the results made available to all airlines and engine manufacturers. Without governmental support, such an open research atmosphere would have been impossible. “Results from these studies.” wrote Colladay and Neil Saunders, “indicated enough promise to initiate the EEE project.”[229] [230] [231]

In the E‘ program, both General Electric and Pratt & Whitney were given the task of building a new turbofan engine. But the idea was not for them to build a commercial-ready engine. The E; engine was to be used primarily for testing and proof of fuel-efficient concepts. The new technological components included a compressor, fan, turbine-gas-path improvements, structural advances, and improved blading and clearance control. Although the contractors had the same goal, they approached their work within Ел differently.[232] Pratt & Whitney engineers took a

The Frontiers of Engine Technology — The Energy Efficient Engine

Energy Efficient High Pressure Compressor Rig (April 10. 1984). (NASA Glenn Research Center [NASA GRC|.)

“component” strategy and concentrated on developing a high-pressure turbine that could be operated with a lower temperature of hot gas to improve efficiency. General Electric proceeded with a more compre­hensive approach, researching the best way to integrate a new fan. high – pressure compressor, and low-pressure turbine. According to Jeffrey Ethell. the freedom that the contractors had was important: “The ‘clean sheet’ opportunity. .. gave both companies the chance to leave their nor­mal line of evolutionary development and leap forward into high-risk. .. areas to research and aggressively push the frontiers of technology.”[233] Along with these two prime contractors, there were subcontracts with major commercial airframe manufacturers. Boeing, Douglas, and Lockheed provided expertise in areas related to airplane mission defini­tions and engine and airframe integration. Just as in the ECI program. Eastern Airlines and Pan American also provided ongoing evaluation of the results from the perspective of the airlines. NASA also planned to use its own in-house technological advances and other contractors to support specific program needs. NASA never intended to develop a new engine as a product. This was a project for the engine manufactur­ers to achieve after NASA assisted with the proof of concepts. Elements of the ECI program such as improved fans, seals, and mixers were incorporated into the E‘program, and the E‘engineers were also able to apply results from the ECI Engine Diagnostic program to improve engine performance.[234]

A first step in the E’ program was to identify risk factors that might potentially cause the new engine to fail. In an April 1976 letter from James Kramer. Director of the ACEE office, to Donald Nored. the chief of the Energy Conservative Engines Office at Lewis, Kramer asked that the Center perform a “risk assessment of the total E‘ program.”[235] With a list of potential failures in hand, the Center could better under­stand the implication on schedules, cost, and program success. A separate action plan could then be put in place to reduce these risks. Two months later, Nored and Lewis completed the risk assessment. “By nature," wrote Nored, “this is a high risk program, as is true of most advanced technology programs, and there is no way to make it a safe bet.”[236] The best way to minimize risk, according to Nored. was to use multiple con­tractors who were supplied with adequate funds. Both General Electric and Pratt & Whitney took on separate areas of risk that were unique challenges to their approaches and engines. With both companies involved. Nored believed “at least one-half or greater of the stated goal” would be achieved.

As the program got underway, one important advance was a com­puter control system known as a full authority digital electronics control (FADEC). It could monitor and control 10 engine parameters at the same time and communicate information to a pilot. Sensors were known to be one of the least reliable of all engine components. The FADEC system was able to compensate for this problem in case of failure by modeling what the engine should be doing at any given time during a flight. If the sensor failed, then the FADEC. based on its model, could tell the various engine components what they should be doing.[237]

In 1982, budget reductions caused “program redirection” for the EJ project. According to Cecil C. Rosen, the manager of the Lewis propulsion office, this meant changes for both General Electric and Pratt & Whitney in how they planned to complete the project. General Electric proceeded with its core engine test and suspended work on emissions testing and an update for a flight propulsion system. For Pratt & Whitney, the redirection meant a continued focus on component technology as opposed to an over­all engine system evaluation. The main concern with this plan was that it provided more funding for Pratt & Whitney than General Electric because it had “much farther to go in its component technology efforts.” Rosen hoped this “unequal funding,” which went against the original spirit of the E’ program, would be acceptable.[238] [239] [240] [241]

General Electric completed the program with a great deal of success and as early as 1983 was being called the “world’s most fuel-efficient and best-performing turbofan engine.”6′ Bucy, the Program Manager at General Electric, called it “one of the most successful programs on an all-new engine in yearsWhile the low-pressure turbine was a diffi­cult challenge from an aerodynamic perspective, it achieved the desired parameters laid out by NASA at the start of the program to define success. There is a 13-percent improvement in fuel efficiency over the CF6-style engine, which was 1 percent better than required. GE immediately began to incorporate the new technology into its latest engine designs, including the CF6-80E, the latest engine for the Airbus A330, and the GE90 engine for the Boeing 777.M The GE90 first made headlines in 1991 because it “pushed the edge of technology ” not only because it was more efficient, but also because it used another ACEE project. It became the only engine to use composite fan blades, making it 800 pounds lighter, with a 3.5-per­cent fuel savings. It also had a cleaner burn, producing 60 percent less nitrous oxide, and was quieter. Though it was a larger engine, its engineers believed that the wind whistling over the landing gear would produce more noise than the engine. As Christopher D. Clayton, the manager of the GE90 technical programs said,‘’It will give us a much more efficient engine. That’s the real purpose of it."[242] [243] The 777 now Hies with an engine based directly upon the one developed through the efforts of the E’ ACEE program.

Pratt & Whitney also had success with its energy efficient engine technology, though at a slower pace. In 1988, it reported that the “effi­ciency trends show a steady increase”’1 with the E3 technology. But the company still had research to perform to enable it to realize the gains for “tomorrow’s engine." These successes were finally realized in 2007, when it launched the new energy-efficient Geared Turbofan as the engine for the Mitsubishi Regional Jet. This was a 70- to 90-seat passenger aircraft, and Mitsubishi planned to purchase 5,000 of them over the coming 20 years. The technology for this engine could be directly traced back to Pratt & Whitney’s participation in the ACEE program.[244]*

These favorable results of the E* program, as well as the achievements of the EC1 program, resulted in enthusiasm for ACEE. In 1979, Colladay said, “This early success in the first of the ACEE Program elements to near completion is certain to continue as more of the advanced concepts are put into production.”[245] However, this “continued certainty” was seri­ously threatened in 1980 with a new presidency on the horizon. Unlike ECI, which returned such fast and positive results, the other ACEE pro­grams required a longer window to develop and prove their technologies, and their engineers required a commitment of time and money from the United States Government to ensure that their research continued. Just 3 years after the entire program began, there were serious concerns not only for the future of ACEE. but for the future of all aeronautics activi­ties at NASA. For the ACEE participants, the question was: Would the Government terminate such a vital fuel-efficiency program to the Nation early, when it had already had such success with its shorter-term projects like the Engine Component Improvement? For NASA, the question was even more dire: Would the Agency be allowed to continue its work in aeronautics?

The Frontiers of Engine Technology — The Energy Efficient Engine

Aeronautics Wars. at NASA

Aeronautics Wars. at NASAn September II, 1980, 2 months before the presidential elec­

tion. Ronald Reagan wrote a letter to Gen. Clifton von Kann, the senior vice president at the Air Transport Association of America. In it. he outlined the aeronautical objectives of his potential presidency, as well as his criticisms of the Carter era. While not questioning the importance of aviation to the economic and military strength of the Nation. Reagan was highly critical of ongoing programs. “1 am deeply concerned about the state of aeronautical research and development,” he wrote, using as an example the “alarming” slowdown in aircraft exports to other nations, an industry the United States had once dominated. He identified energy efficient aircraft as one critical aviation issue facing the Nation, and of these efforts, he wrote, “Our technological base is languishing.” Reagan promised von Kann, “The trends must be reversed. And I am committed to do just that.”1

Soon after Reagan assumed the presidency, a conservative think tank that played a major role in shaping the philosophy of his Administration made the shocking assertion that the NASA aeronautics program was actu­ally eroding the country’s leadership in aviation. The group, the Heritage Foundation, said. “The program should he abolished."[246] [247] The new Reagan Presidential Administration began to seriously consider taking aeronautics away from NASA and letting industry assume the primary role in research. Richard Wagner, the head of the Laminar Flow Control program at Langley, said, when “Reagan came into office… we didn’t know whether

Aeronautics Wars. at NASA

President Ronald Reagan gets a laugh from NASA officials in Mission Control when he jokingly asks astronauts Joe Engle and Richard Truly if they could stop by Washington en route to their California landing. To his right is NASA Administrator James Beggs (November 13.1981). (NASA Headquarters-Greatest Images of NASA (NASA HQ GRIN].)

we were going to stay alive or not. . . it was a struggle.”’ It was an even greater struggle for his colleagues at Lewis Research Center, as the entire base was threatened with closure. The conflict between NASA and other Government agencies had started slowly in 1979, with general disagree­ments over language in an ACEE report by the Government Accounting Office (GAO). Conflict escalated over budget reductions in 1980 and subsequent cuts for ACEE. But by 1981, the clash became a full-on fight for survival as the Reagan Administration pushed for the closure of Lewis Research Center, the elimination of aeronautics from all of NASA, and the termination of over 1.000 aeronautics jobs. These were the aeronautics wars.