Takeoff (climb)

After takeoff from runway 01/19 at La Vertiente Airport, both engines lost power. The aircraft lost height, struck trees and crashed in a field some 300 metres past the runway end. A crew member and nine passengers were killed while nine other occupants were injured. The aircraft was completing a charter flight to Santa Cruz-Viru Viru Airport on behalf of Servicios Aéreos Vargas de España (SAVE), carrying employees of the Tesoro Bolivia Petroleum Company based in San Antonio, Texas.

The four engine aircraft departed Irkutsk-2 Airport on a cargo flight to Cam Ranh Bay, with an intermediate stop in Vladivostok, carrying 15 passengers, eight crew members and a load consisting of two Sukhoi SU-27UB fighters to be delivered to the Vietnam Air Force. Three seconds after takeoff from runway 14 at Irkutsk-2 Airport, at a height of 5 metres, the engine n°3 failed. Six seconds later, at a height of 22 metres, both left engines n°1 and 2 also failed. The aircraft pitched up and entered a high angle of attack, climbed to a maximum height of about 66 metres then rolled to the left and crashed onto several buildings located 1,600 metres from the runway end. The aircraft was totally destroyed by impact forces and a post crash fire as well as several buildings. All 23 occupants and 45 people on the ground were killed. Hundred other people on the ground were injured, some seriously.

The pilot, who was also the station manager, arrived at the airport earlier than other company employees to prepare for a scheduled commuter flight, transporting seven passengers and cargo to another village during hours of arctic, predawn darkness. Heavy frost was described on vehicles and airplanes the morning of the accident, and the lineman who serviced the airplane described a thin glaze of ice on the upper surface of the left wing. The pilot was not observed deicing the airplane prior to flight, and was described by the other employees as in a hurry to depart on time. The pilot directed the lineman to place fuel in the left wing only, which resulted in a fuel imbalance between 450 and 991 pounds (left wing heavy). The first turn after takeoff was into the heavy left wing. The airplane was observed climbing past the end of the runway, and descending vertically into the water. No preimpact mechanical anomalies were found with the airplane or powerplant. The aileron trim indicator was found in the full right wing down position. Postaccident flight tests with left wing heavy lateral fuel imbalances, disclosed that approximately one-half of right wing down aileron control deflection was used to maintain level flight, thus leaving only one-half right wing down aileron control efficacy. Research has shown that frost on airfoils can result in reduced stall angles of attack (often below that required to activate stall warning devices), increases in stall speeds between 20% and 40%, asymmetric stalls resulting in large rolling moments, and differing stall angles of attack for wings with upward and downward deflected ailerons (as when recovering from turns).

The single engine aircraft was engaged in a local skydiving flight on behalf of the CERP of Picardie. After takeoff from runway 35, while climbing to a height of about 1,000 feet, the aircraft rolled to the right, entered an uncontrolled descent and crashed in a swampy area located about 1,500 metres east of the airfield. The aircraft was totally destroyed and all nine occupants were killed.

The pilot reported that the airplane lifted off at 70 knots. After accelerating in ground effect the airplane became 'unstable in the roll axis' so he added power. He reported that the left wing tip contacted the runway approximately 3/4 the way down the runway. The pilot then added additional power at which point the left wing contacted the grass off the left side of the departure end of the runway. The pilot then reduced the power to idle and landed the airplane in the grass collapsing the landing gear. The pilot reported that the engines sounded normal throughout the accident sequence. Investigation revealed another Beech 18 had taken off on the same runway, but in the opposite direction of N916TM less than one minute prior to the accident.

The float equipped airplane was observed taking off in light winds and calm water, and obtaining a steep climb and nose high attitude. Witnesses described hearing no reduction of engine noise from takeoff power to climb power. The airplane entered a steep left bank about 200 feet above the water, then rolled rapidly to the right and impacted at a steep angle into the water. The airplane had been modified with a Short Take Off and Landing (STOL) kit. Certification flight tests had determined that this modification eliminated aerodynamic warning of impending stalls, and therefore required an audible stall warning. Test results also required the addition of both a ventral fin, and horizontal stabilizer finlets, to meet directional stability certification. These tests determined that the least stable condition was in the takeoff flap configuration, during climb. The Supplemental Type Certificate (STC) for the modification required the ventral fin, and an audible stall warning system be installed. The manufacturer provided a marketing video, produced prior to the STC approval, which stated the stall warning system was not required in the U.S. The company indicated this tape was used for training, and was a basis for pilots routinely disabling the stall warning horn by pulling the circuit breaker. At the time of the accident, the airplane did not have the ventral fin installed, a takeoff flaps setting was selected, and the audible stall warning circuit breaker was in the pulled (disabled) position. The local FAA Flight Standards Office had inspected the accident airplane 14 times in the previous 29 months, and made no mention of the ventral fin not being installed.

During the takeoff roll, the aircraft went out of control, veered off runway and came to rest in a ditch. All 10 occupants escaped uninjured while the aircraft was damaged beyond repair.

During the takeoff roll from Najran Airport runway 06/24, at a speed of 95 knots, the right engine thrust suddenly increased. Few seconds later, at a speed of 120 knots, the exhaust gas temperature warning came on in the cockpit panel. The captain decided to abort and initiated an emergency landing procedure. Speed brakes were deployed but the thrust reversers could not be activated. Unable to stop within the remaining distance, the aircraft overran, lost its undercarriage and right engine before coming to rest. All 85 occupants evacuated safely.

The crew consisting of pilots and technicians were completing a training flight after PADC just acquired this aircraft. Shortly after takeoff from Fortune Island, the twin engine aircraft crashed in unknown circumstances in the sea. SAR operations were initiated and few debris were found floating on water three days later. All five occupants perished.

After takeoff, the twin engine aircraft collided with trees and crashed, bursting into flames. The pilot, sole on board, was killed. Takeoff from Ahlhorn?