Dobbins AFB

The aircraft was designed and used as the company's engineering test bed. An evaluation of the fly-by-wire rudder actuator and ground minimum control speed (vmcg) was being conducted. During the final hi-speed ground test run, the aircraft abruptly veered left and became airborne. It entered a left turn, climbed to about 250 feet, departed controlled flight and impacted the ground. Investigation revealed a design feature in the rudder actuator that removes hydraulic pressure within the actuator if the rudder position commanded by the pilot exceeded the actual rudder actuator position for a specified time, and the rudder aerodynamically trails. The actuator previously disengaged in flight. The company did not conduct a system safety review of the rudder bypass feature and its consequences to all flight regimes, nor of the vmcg test. The flight test plan specified that engine power be retarded if the rudder became ineffective. Neither pilot had received training as an experimental test pilot. The company allowed experimental flight tests at a confined, metropolitan airport. All seven occupants were killed.

During gear retraction after takeoff, the right main gear became jammed in a partially retracted position and the respective in-transit gear light would not extinguish. Attempts to recycle the gear were unsuccessful. The flight crew diverted to Atlanta, GA; then decided to land at Dobbins AFB, where there was a long, wide runway that could be foamed. Foam was applied to approximately 300 feet of runway 29. The aircraft was landed with the nose and left main gear extended and the right main gear partially retracted. Subsequently, the aircraft veered to the right and stopped with the nose gear approximately 70 feet off the runway. Fire erupted in the area of the right main gear; however, the fire was quickly extinguished by fire dept personnel. An investigation revealed the clearance between the main landing gear door hook, pn 803845-1, and the strut roller was excessive. The reason for the improper clearance was not determined. Lockheed service bulletin 88/sb-558 warned that excessive clearance combined with a drop in hydraulic pressure, gust or maneuver could result in the gear jamming. All three crew members were uninjured.

The twin engine airplane departed Dobbins AFB on a local training flight, carrying two pilots and one instructor. While flying at an altitude between 1,900 and 2,100 feet, the crew reduced the speed, lower the gears and the flaps then initiated a 180 turn when control was lost. The aircraft entered a dive and crashed in a wooded area located in Hiram, bursting into flames. All three occupants were killed.
Crew:
Cw2 James Q. Tyner Jr.,
Civ John R. Bailey,
Maj David M. Bishop.

The crew was performing a flight from Harlingen AFB, Texas, to New York with an intermediate stop at Dobbins AFB, Georgia. The accident occurred in unclear circumstances, killing both crew members, Cpt Cecil Bryant and 1st Lt Donald Carillo.