Merica Catches Up
The U. S. aircraft industry took its cue from its potential customers. The industry was obviously not interested in designing and building airplanes unless and until a market existed for them. The concept of the turboprop (the turbine jet engine used to drive a propeller) was considered the likely next commercially successful form of propulsion, and research and development efforts were stepped up both in military and commercial circles, particularly at Lockheed.
There was one other possibility. Boeing’s reputation as a builder of military aircraft, mainly bombers and tankers, was unequalled. But Douglas and Lockheed were far ahead of Boeing in the commercial transport field. Boeing had taken a back seat to Douglas and Lockheed in every commercial airliner contest thus far—the B-247 ran second to the DC-3, the B-307 lost out to the Connie and to WWII, and the B-377 could not compete with the DC-7 and the Super Constellation. Boeing had built the C-97 piston engine tanker for the Air Force, but it was not adequate for fueling the new jet bombers, the B-47 and the B-52. The Air Force, Boeing reckoned, would be in the market for a new jet tanker.
Boeing decided to take the gamble. On April 22, 1952, Boeing’s board of directors authorized the expenditure of one-fourth of the company’s total net worth, $15 million, to develop a prototype. Neither the airlines nor the military had actually expressed an interest in purchasing such an airplane, nor had any appropriation been secured in Congress for replacing the C-97. Boeing officially designated the project the model 367-80, and it was known internally at Boeing as the “dash 80” thereafter. But the designation that the world would come to know was the “707.”
Boeing had the largest and the only state – of-the-art wind tunnel for testing aircraft shapes. The development of this wind tunnel, in fact, had been responsible for the adoption of the swept-wing design first incorporated in the B-47. (See Figure 19-5.) The 707 design was adapted through wind tunnel testing for over 4,000 hours. Redundant systems, overlapping structural components, multiple strength round windows, plug
FIGURE 19-5 A KC-97 refueling a B-47. |
Source: Florida State Archives. |
type doors for better pressurization seals, and spot welds set the standard for the jet aircraft production industry to come. The exterior shell of the 707 was engineered before the Comet disasters. Boeing decided that the skin of the aircraft would be aluminum, of a thickness that turned out to be 4’/2 times as thick as the Comet’s (the Comet’s exterior shell was so designed in order to save weight). Boeing also incorporated a new alloy, known as titanium, that was as light as aluminum but stronger than steel, to bolster the strength and fatigue resistance of the 707’s skin. Then the engineers put the design through 50,000 pressurization cycles with no evidence of metal fatigue.
Tests revealed that the positioning of the aircraft’s engines on pylons slung underneath the wings provided the best lift efficiency and had the added benefit of allowing easy access to the engines for maintenance. The wings were also designed to carry 17,000 gallons of fuel, thus allowing for nonstop transcontinental range.
In 1952, Douglas was investigating the feasibility of jet-powered airliners but only went so far as to construct a full-scale wooden mockup of what was to become the DC-8. The problem in the industry, with both manufacturers and carriers, was one of confidence. None of the industry leaders could seem to project a solution to the financial impact of the cost of construction of the highflying jet airliner and its cost of operation, particularly from the fuel standpoint. The J-57 was still not available. Projections of cost per aircraft approximated $4 million, contrasted to the $1.5 million price tag of the DC-7. Aviation industry leaders were not convinced that jets were commercially viable. C. R. Smith of American Airlines was of the opinion that in order to justify going to jetliners, the cost of operating them should be no higher than the cost of operating the DC-6. Of course, no one knew what the costs of operation of a jet fleet would be. Fuel consumption could be projected, but some costs, such as parts, maintenance, and engine life (time between overhaul, or TBO) would have to await experience. Among the Americans, only Juan Trippe dissented.
Trippe had been interested in the De Havilland Comet when it first came out, and had placed orders for three of the airplanes subject to their specifications meeting the United States Civil Aeronautics Administration requirements. There was, in fact, some concern that the CAA would not grant the Comet an airworthiness type certificate based on CAA reservations (prophetic, as it turned out) about the square corners of the windows in the aircraft. The CAA had recommended oval windows but De Havilland appeared to be satisfied with its design, citing design safety tolerances much in excess of expected stresses. Subsequent events would tragically vindicate the CAA’s position but, without U. S. approval, Trippe was left in the age of piston aircraft. By the time the problems with the Comet had been rectified in the redesign of the Comet 4, in 1958, the 707 was light years ahead of the old Comet design. The Comet, for instance, had seating for 67 while the 707’s capacity was 130.
Boeing’s gamble paid off when, in March 1955, it received its first order for the 707, not as the anticipated passenger airliner, but as the first jet tanker ordered by the Air Force. The first 707 was rolled out of its hangar at Renton, Washington, in May 1955, and completed its maiden flight on July 15, 1955. The 707 prototype would undergo flight testing for the next three years before being placed in commercial airline service. The largest aircraft then in commercial service was the Boeing Stratocruiser and the 707 was 15 times more powerful, twice as fast, and almost twice as big. Douglas, now convinced of the feasibility of building civilian jet aircraft, announced that it would complete its design and begin production of the DC-8.
Pan American, alone among the American carriers, seemed interested in jets, despite their projected economic indicators. Trippe had seen how the public had abandoned piston-powered airplanes in droves for the Comet, and it was his purpose to be the first to supply the high-flying, vibration-free, 500-mile-per-hour airplane of the future to America. Just as he had been among the first to abandon the wood and wire airplane and put the Fokker Trimotor all-metal cantilevered monoplane in service in 1928 (Key West to Havana), the first to inaugurate extended over-water service in the great Clipper amphibians, the first to offer his airline passengers hotel accommodations in his own hotels at their destinations, and among the first to switch to pressurized aircraft, he was now the first to order the first U. S.-produced commercial jet airliner. He did so against the prevailing industry tide in October 1955 with the announcement that he had ordered 20 Boeing 707s and, to the great delight of Douglas who did not actually have a real airplane in existence, twenty-five Douglas DC-8s. At a total capital outlay of $269 million, Pan American had committed to the largest airplane acquisition in the history of the industry.
The 707 and the DC-8 were so similar in appearance that it was hard to distinguish between them. But there were real differences to the potential customers, the airlines. First was cabin width, then length, then seating capacity, then the engines. The airlines seemed to prefer the DC-8 design. Before very long, Douglas had twice the orders for DC-8s than Boeing did for 707s. Boeing began making modifications, first to widen the fuselage to a dimension one inch wider than the DC-8, then to increase its length, wingspan, and range. Soon, it had another version of the original 707, and this time the airlines liked it. In 1955, Douglas outsold Boeing, only to be put in second place at the end of 1956. The airlines were now getting caught up in the idea of the jet age, and orders began to pour in. United States airlines bought, but so did foreign airlines. Eastern, Delta, KLM, SAS, Japan Air Lines, and Swissair all bought Douglas. American, Continental, Western, TWA, Air France, Sabena, and Lufthansa went with Boeing. Boeing had finally broken the old jinx of second best. All told, Boeing would win the numbers competition against Douglas by almost 2 to 1. The most satisfying event, though, might have been the selection by the president of the United States of the Boeing 707 as the first jet Air Force One, in 1959.
Lockheed declined to enter the competition, concentrating on the turboprop as its best guess of where the future of commercial aviation lay. Lockheed’s contribution was to be the Electra, which in 1957 became the first propjet put in service by U. S. airlines. Only 169 planes were produced, some for the Navy, designated as the P-З. Convair submitted its 880 in 1959 but was unable to compete with the Boeing and Douglas jetliners, losing some $270 million for its efforts.
On October 26, 1958, Pan American became the first American air carrier to inaugurate scheduled jet service with the 707 on its New York to Paris flight. National Airlines was next on December 10, 1958, with a 707 leased from Pan Am that was put on the New York-Miami run to mark the first domestic jet service. Eastern was flying the same route with Lockheed Electras, and immediately began losing out to National. American followed domestically by putting the 707 to work on the transcontinental route, then TWA. United was out of action awaiting the delivery of the first DC-8s, still in the production phase. Eastern could not seem to accept that the jet age had really arrived, and was woefully late in acquiring its first jets, much to its economic disadvantage against its competitors.
On any competitive route in the late 1950s, jets trounced the piston airplanes. The flying public loved jets, and this translated into filled passenger seats. The load factor went up dramatically on jet routes, and their capacity was almost twice that of the DC-7. The airlines were surprised to find that the reliability of the new jet engines greatly reduced failure concerns which had become commonplace with the great turbocompound piston engines, and that replacement parts and maintenance costs were much lower than expected. Time Between Overhaul (TBO) was a federally mandated life expectancy of the piston engine used in commercial service in the late 1950s, and it was about 800 hours. The FAA found that jet engines could greatly exceed this limit, and gradually raised the TBO for jets to
4,0 hours. This artificial limit was ultimately discarded entirely in favor of a progressive maintenance schedule designed around the few critical components of the jet engine.
Passenger-mile costs proved to be about the same as on the DC-7. Although fuel consumption in the 707 was much higher than the DC-7, the actual passenger miles per gallon for the 707 was 42 compared to the 59 passenger miles per gallon for the DC-7. The lower cost for jet fuel (kerosene) compared to high-octane gasoline off-set this slight difference. The economics of commercial jet travel were working out after all, and the flying public embraced the jet age.