Test

The pilot was completing a local post maintenance test flight at Cooinda Airport. Shortly after takeoff, while in initial climb, the engine failed. The pilot attempted an emergency landing in the bush but the aircraft collided with a telephone pole and came to rest. The pilot escaped with minor injuries and the aircraft was damaged beyond repair.

The pilot, sole on board, was performing a local test flight following an engine overhaul. En route, the engine lost power. The pilot attempted an emergency landing when the aircraft crashed in an open field located 6 km northeast of Dmitrievskaya, bursting into flames. The aircraft was destroyed and the pilot was seriously injured.

The aircraft was on a post maintenance delivery mission. A crew of two engineers was positioning the aircraft from a technical hangar at Caracas-Maiquetía-Simón Bolívar Airport to the main terminal. While taxiing on the ramp, the crew lost control of the aircraft that rolled to a grassy area and eventually collided with a drainage ditch. The left main gear collapse and the left wing was severely damaged. Both crew were uninjured while the aircraft was damaged beyond repair.

The aircraft registered F-WWCJ was tested at a fixed point at Toulouse-Blagnac Airport. The current mission consisted of various test' systems with airline technicians who had ordered the plane. It unfolded engines in operation without chocks wheel. At the end of these tests, after having stopped and inspected the engines, the technicians restarted them for a new fixed point at high power, to find the source of oil seeps. About three minutes after power-up, the aircraft began to moving forward. The technician in the left seat noticed the movement and informed the test technician in the right seat. The latter acted on the brakes located rudder pedals then released the parking brake. The DFDR then shows a release of the brake command with the rudder bar. As the plane continues to advance, he tried to deviate from his course using the steering wheel. The nose gear quickly got in the way as the plane accelerated. The plane struck an inclined blast wall. Its front part broke and flipped over to the other side. Thirteen seconds elapsed between the start of the aircraft's movement and the shock with the wall. The aircraft was destroyed and all nine occupants were injured, four seriously.

While on downwind the airplane experienced a loss of engine power and collided with houses and other obstacles during a forced landing on a residential neighborhood street. The pilot stated that he took off to troubleshoot a landing gear anomaly. He departed the airport area to the south. He cycled the landing gear and upon getting questionable indications in the cockpit of gear position he requested another aircraft confirm his landing gear configuration. Once he got the confirmation that all three wheels were down he proceeded back to the airport. About 2 miles away and approximately 1,800 feet agl the right engine began to lose power. He troubleshot the engine by attempting a restart, cycling the fuel pump off then on, and selected the right auxiliary fuel tank. The right engine did regain some power. He had lost some altitude during the process of troubleshooting the engine. He raised the landing gear to reduce drag, and entered right hand traffic for runway 17. At this point the left engine lost power, the airplane turned left, and he entered a descent to help maintain airspeed. He put the left propeller in feather, and switched to a new fuel tank, but the engine did not regain power. He did not have any altitude to exchange for airspeed and steered the airplane towards a clear residential street. The airplane impacted the roofs of at least two houses before colliding with the street. The pilot egressed through the rear of the airplane. An FAA inspector that examined the airplane wreckage stated that there was very little evidence of fuel onboard the airplane. The pilot stated that the left engine had failed due to fuel starvation and that he had fuel onboard but it was not in the right places.

With all cockpit indications showing the landing gear was down and locked, the airplane touched down on the runway. Immediately after touchdown, the pilots heard the landing gear warning horn sound intermittently for several seconds, and then the right main landing gear collapsed. The airplane veered to the right, exited the runway, and came to rest. A post crash fire ensued, and the crew exited without injury. A postaccident examination of the airplane revealed that the collapsed right main landing gear had penetrated the right main fuel tank and the majority of the right side of the fuselage had been consumed by fire. Examination of the left and right main landing gear assemblies revealed, that both downlock plates had been installed backwards, providing only a fraction of the design contact area between the plate and throat of the downlock hook. Examination of the manufacturer's component maintenance manual, which was used for the assembly and installation of the left and right main landing gear, revealed no guidance regarding downlock plate orientation during installation.

The proto-type experimental light jet airplane was departing on a local maintenance test flight. Witnesses reported that the airplane entered a right roll almost immediately after liftoff. The roll continued to about 90 degrees right wing down at which point the right wingtip impacted the ground. During examination of the wreckage, the aileron control system was found connected such that the airplane rolled in the opposite direction to that commanded in the cockpit. The maintenance performed on the airplane before the accident flight included removal of the main landing gear (MLG) in order to stiffen the MLG struts. Interviews with the mechanics who performed the maintenance revealed that during re-installation and system testing of the MLG, it was discovered that the changes to the MLG struts impacted the Vbracket holding the aileron control system's upper torque tube. The V-bracket was removed and a redesigned V-bracket was installed in its place. This work required the disconnection of a portion of the aileron control system, including the removal of the aft upper torque tube bell crank from the torque tube. The mechanic who reinstalled the aft upper torque tube bell crank was under the incorrect assumption that there was only one way to install the bell crank on the torque tube. However, there are actually two positions in which the bell crank could be installed. The incorrect installation is accomplished by rotating the bell crank 180° about the axis of the torque tube and flipping it front to back, and this is the way the bell crank was found installed. With the bell crank installed incorrectly and the rest of the system installed as designed, there is binding in the system. This binding was noticed on the accident airplane during the inspection after initial installation. However, the mechanic did not recognize that the bell crank was improperly installed on the torque tube. Instead of fixing the problem by removing and correctly reinstalling the bell crank, he fixed the problem by disconnecting the necessary tie rods and rotating the upper torque tube so that the arm of the bell crank pointed up and to the left. This action reversed the movement of the ailerons. According to all of the personnel interviewed, there was no maintenance documentation to instruct mechanics how to perform the work since this was a proof-of-concept airplane. None of the mechanics who performed the work could recall if the position of the ailerons in relation to the position of the control stick was checked. Such a position check, if it had been performed by either the mechanics after the maintenance or by the flight crew during the preflight checks, would assuredly have indicated that the system was installed incorrectly.

According to the pilot, passenger, and several witnesses, during takeoff the light jet became airborne momentarily, and then banked aggressively to the left. It impacted the runway in a left wing low attitude and cartwheeled down the runway. An examination of the airplane's systems revealed no anomalies. Approximately 1.5 minutes before the airplane was cleared for takeoff, a De Havilland Dash 8 (DH-8) airplane departed. A wake turbulence study conducted by an NTSB aircraft performance engineer concluded that even slight movement in the atmosphere would have caused the circulation of the vortices near the accident site to decay to zero within two minutes, that is, before the time accident jet would have encountered the wake from the DH-8. The study states, in part: "Given the time of day of the accident, consistent reports of easterly surface wind speeds on the order of 6 to 7 knots, higher wind speeds aloft, and the mountainous terrain near Colorado Springs, it is unlikely that the atmosphere was quiescent enough to allow the wake vortices near the Sport-Jet to retain any significant circulation after two minutes. Furthermore, easterly surface winds would have blown the wake vortices well to the west of the runway by the time of the accident. Consequently, while in smooth air the wake vortices from the DH-8 that preceded Sport-Jet off of the runway may have retained enough circulation after two minutes to produce rolling moments on Sport-Jet on the order of the rolling moment available from the Sport-Jet's ailerons, it is most likely that the wake vortices were neither strong enough nor close enough to the Sport-Jet to cause the violent roll to the left reported by the pilot and witnesses to the accident."

The crew was performing a test flight on this aircraft that was parked for 10 years at Kinshasa-N'Djili Airport. On landing, the left main gear collapsed and the aircraft came to rest. All seven occupants escaped uninjured while the aircraft was damaged beyond repair. The General Kikunda Ombala was PIC at the time of the accident.

After takeoff for a maintenance check flight, both engines on the twin-engine airplane experienced a loss of engine power. The 7,200-hour pilot had recently purchased the airplane, which had not been flown for nearly four years. The pilot, who is also a certificated airframe and powerplant mechanic, completed the inspection of the airplane prior to takeoff. During the engine run-up, the pilot noticed that the RPM and manifold pressure on the left engine did not correspond with those of the right engine. During the takeoff roll, the pilot believed the RPM on both engines began to rise to near acceptable levels, but not entirely. However, he did not abort the takeoff. The airplane became airborne for a short time, and then began to descend into trees before impacting the ground. The reason for the reported loss of engine power could not be determined.