Test

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.

The crew was engaged in a local test flight after the right engine has been replaced. After takeoff, while in initial climb, the left engine lost power and smoke came out. The crew decided to return but was unable to maintain a safe altitude. In such conditions, the captain decided to attempt an emergency landing when the aircraft crashed in a swampy area near the airport. All three occupants escaped uninjured while the aircraft was damaged beyond repair.

The aircraft departed Kiev-Gostomel Airport on a test flight part of a certification programme, carrying nine crew members. While cruising at an altitude of 19,000 feet and at a speed of 614 km/h, the radome disintegrated. This caused the front cargo door to open and to detach. Debris struck the engine n°3 that stopped automatically. The aircraft suffered strong vibrations and oscillations then the 3rd hydraulic system failed as well as the flight management system. In such conditions, the crew was unable to get valid data about speed, altitude or the angle of attack. The aircraft entered an uncontrolled descent during which flaps were selected down to reduce the speed, but due to an asymmetrical release of flaps, the descent rate increased until the aircraft crashed in a wooded area located 1,5 km south of Korda and 43 km west of Gostomel Airport. The aircraft was destroyed and eight occupants were killed. The engineer survived after he bailed out during the descent but was seriously injured.

According to the owner, he and the pilot had flown from Albany, Georgia to swap a Piper 28 for the Aero Commander 680. Prior to completing the trade, the previous owner reconstructed a set of aircraft maintenance logs which revealed the estimated total airframe time and engine serial numbers. The owner assumed that the airplane was airworthy. Since the pilot was not Aero Commander rated, they decided to taxi the airplane on the ramp and runway to gain some experience. While taxiing at a high rate of speed on runway 09, the owner reported that a gust of wind caught the airplane as the taxi speed approached 65 mph. The pilot lost control of the airplane as it became airborne. The airplane rotated to the right and the right wing struck the ground; the airplane cartwheeled to a stop facing the opposite direction. The wreckage examination failed to disclose a mechanical malfunction. Reportedly, the pilot completed a preflight but, the wreckage examination discovered a large bird's nest in the sump area of the left engine and a missing exhaust manifold. The pilot was not multi engine rated. The pilot was killed and the passenger was seriously injured.

The pilot was conducting a functional test flight and qualitative engineering evaluation of the airplane's longitudinal control during landing. During final approach to runway 12L, he reduced the engines to the flight idle positions and established 95 kias. He was unable to raise the nose of the airplane during the flare to arrest the descent rate and landed hard onto the runway. The airplane was taxied to the ramp and secured. No mechanical failure was found or reported.

Crashed in the Caspian Sea about six minutes after takeoff when leaving the ground effect for unknown reasons. Crew fate unknown.

Following maintenance, the crew was engaged in a local test flight at Gimli Airport. Shortly after takeoff, while climbing steeply to a height of about 200 feet, the aircraft entered a right turn then nosed down and crashed near the runway, bursting into flames. All three occupants were killed.

The maintenance test flight was being flown following completion of airworthiness directive 87-02-02 requiring the mandatory replacement of all primary flight control cables. Following lift-off, witnesses observed the airplane start a rapid roll to the right until initial impact was made with the ground by the right wing tip. Examination of the wreckage revealed the a half turn in the routing of the replaced flight control cable was inadvertently omitted on both control columns which would result in the ailerons operating in reverse of the commanded input. The passenger was the quality control inspector who had inspected and signed off the maintenance performed. According to other company personnel, he had briefed the crew prior to the flight on the purpose of the test flight and the extent of the maintenance that the airplane had undergone. All three occupants were killed.

While parked at Tunis-Carthage Airport for maintenance, the aircraft was under control of engineers/mechanics. When the engines were started for an engine run-up and power increased to 80%, the aircraft ran over its blocks and collided with an hangar. There were no injuries while the aircraft was damaged beyond repair.

The pilot had the waste gates on the turbocharges adjusted and wanted to test fly the airplane after the work was completed. The airplane departed and had reached an altitude of about 1,000 feet when witnesses heard an engine sputter. The airplane was seen making a left turn and enter a nose low, left spin before impacting the terrain. A tear down of the left engine revealed that the exhaust valves in cylinders #3 and #5 were burnt through at the valve head. The #5 exhaust valve had a deep preexisting deep mark on the valve stem. The failures of both valves were sufficient enough to cause a power failure in the left engine. The pilot, sole on board, was killed.