Models and Mother Ships—Utility RPRV and Ultralight RPRV

By the mid-1990s, it was clear to NASA researchers that use of unpiloted vehicles for research and operational purposes was expanding dramat­ically. R. Dale Reed and others at Dryden proposed development of in­house, hands-on expertise in flight-testing experimental UAVs to guide and support anticipated research projects. They suggested that lower risks and higher mission-success rates could be achieved by applying les­sons learned from flight-test experience and crew training. Additionally, they recommended that special attention be paid to human factors by standardizing ground control consoles and UAV operational procedures.

To meet these goals, Reed recommended using two types of low – cost expendable UAVs. The first was a radio-controlled model air­plane weighing less than 50 pounds but capable of carrying miniature downlink television cameras, autopilot, and GPS guidance systems. Requirements for flight termination systems and control redundancy for such an aircraft would be much less stringent than those for larger UAVs, and the model would require much less airspace for flight oper­ations. Reed felt the R/C model could serve as a basic trainer for UAV pilots because the same skills and knowledge are required regardless of vehicle size. Additionally, the R/C model could provide flight research results at very low cost.[998] Second, Reed felt the modified Rans S-12 ("Ye Better Duck”) should be returned to flight status since an ultra­light-type vehicle could duplicate the size and flying characteristics of planned high-altitude RPRVs then being developed. He saw the S-12 as an advanced trainer for NASA UAV crews. The S-12 had not been flown since January 1994 and required a thorough inspection of airframe and engine, as well as replacement of batteries in several of its sys­tems. Reed recommended that Tony Frackowiak of the Dryden Physics Lab be given the task of preparing the "Ye Better Duck” for flight sta­tus and then serving as primary checkout pilot.[999] Reed submitted his proposals to Dryden director Ken Szalai with a recommendation to develop a Utility UAV as a mother ship for small experimental models. Jenny Baer-Riedhart and John Del Frate, Project Manager and Assistant Project Manager, respectively, for the Environmental Research Aircraft and Sensor Technology (ERAST) program, were willing to support the project plan if the Dryden Operations Division provided a require­ment and also pledged strong support for the plan. Research pilots Dana Purifoy, Tom McMurtry, and Steve Ishmael were enthusiastic about the project. Ishmael immediately saw a potential application for the Utility UAV to drop a subscale aerodynamic model of the planned X-33 spacecraft. Project personnel included Reed as Utility UAV project engi­neer, research pilot Purifoy, crew chief/project pilot Tony Frackowiak, UAV systems technician Howard Trent, and UAV backup pilot Jerry Budd.[1000] [1001]

During this time, Reed reactivated the old R/C Mothership that had been used to launch lifting body models in the 1960s. Frackowiak removed and overhauled its engines, cleaned the exhaust system, replaced throttle servos, and made other repairs. During six checkout flights November 25, 1996, the Mothership underwent checkout and demonstrated a 20-pound payload capability. It was subsequently used as a launch air­craft for a model of a hypersonic wave rider and a 5-percent-scale model of the Pegasus satellite booster.123 Meanwhile, Reed had pressed on with plans for the larger Utility UAV. For systems development, Frackowiak acquired a Tower Hobbies Trainer-60 R/C model and modified it to accept several different gyro and autopilot configurations. The Trainer 60 was 57 inches long, had a 69-inch wingspan, and weighed just 8 pounds. Frackowiak conducted more than a dozen test flights with the model in March 1997.[1002] In April 1997, the Mothership was equipped with a video camera and telemetry system that would also be used on the Utility UAV. The first three test flights took place at Rosamond Dry Lake on the morning of April 10, with one pilot inside a control van watching a video monitor and another outside directly observing the aircraft. For the first flight, Frackowiak served as outside pilot—controlling takeoff and landing—while Reed familiarized himself with pitch and roll angles in climb, cruise, and descent. On the third flight, they switched positions so Reed could make a low approach to familiarize Frackowiak with the view from the camera. They found that it helped to have a ground mark­ing (such as a runway edge stripe) on the lakebed as a visual reference during touchdown. Other areas for improvement included the reduc­tion of glare on the video monitor, better uplink antenna orientation, and stabilization of pitch and roll rate gyros to help less-experienced pilots more easily gain proficiency.[1003] In May 1997, Dana Purifoy began familiarization and training with the Mothership. In August, the air­craft was again used to launch the Pegasus model (for deep-stall tests) as well as a Boeing-UCLA Solar-Powered Formation Flight (SPFF) vehicle.

On August 5, Reed piloted the Mothership, while Frackowiak flew the SPFF model.

In September 1997, Frackowiak modified the Mothership’s launch hook to accept a scale model of the Lockheed Martin X-33 lifting body vehicle. The X-33 Mini-RPRV was, like the SPFF model, equipped with its own set of radio controls. Initial drop flights took place September 30 at a sod farm near Palmdale, with John Howell piloting the X-33 model.

Following a series of SPFF flights in October, the Mothership was taken to Air Force Plant 42 in Palmdale for more X-33 Mini-RPRV drops. On February 12, 1998, interference led to loss of control. The Mothership crashed, sustaining severe but repairable damage to wing and nose.[1004]

While the Mothership was undergoing repairs, Frackowiak com­pleted construction of the 30-pound Utility UAV in April 1998. On April 24, he took the airplane to Tailwinds Field, a popular R/C model airstrip in Lancaster, for its first flight. Takeoff at partial power was uneventful. After gaining 300 feet altitude, Frackowiak applied full power to check the trim then checked controllability in slow flight before bringing the Utility UAV in for a smooth landing.

By the end of June, the aircraft had been cleared to carry payloads weighing up to 20 pounds. Three months later, the Utility UAV was

modified to carry the X-33 Mini-RPRV. On September 10, Reed and John Redman began a series of captive flights at Rosamond Dry Lake. Drop testing at Rosamond began 4 days later, with 4 successful free flights made over a 2-day span to evaluate higher X-33 model weights and a dummy nose boom.[1005] On October 1, 1998, the Utility UAV made its 20th flight, and the X-33 model was released for the 5th time at Rosamond. Piloted by Frackowiak, the lifting body’s steep descent ended with a flaw­less landing, but disaster lurked in wait for the drop plane. As Redman maneuvered the Utility UAV toward final approach, he watched it sud­denly roll to the left and plunge into the clay surface of the lakebed, sus­taining major damage.[1006] Further testing of the X-33 Mini-RPRV was undertaken using the repaired Mothership. Several successful drops were made in early October, as well as a familiarization flight for research pilot Mark Stucky. Reed noted in his log: "The Mothership has again proven the practicality of its design, as it has been flawless during these launches. And it is very good to see it flying and performing useful missions again.”[1007]