Takeoff (climb)

The twin-engine Aerostar departed on Runway 1. While on initial climb, after take-off, witnesses observed the airplane roll to the left until it became inverted, after which the nose dropped and the airplane impacted the ground in a near vertical nose down attitude. The fuselage was consumed with a post crash fire. On-site examination revealed the wing flaps and landing gear were retracted. No evidence of a mechanical failure or malfunction was found relating to the airplane, engines, or propellers. The investigation revealed that both propellers were rotating and absorbing power at the time of impact. The winds were reported from 360 degrees at 17 knots, with gusts to 25 knots.

The pilot lost control of the airplane following the loss of engine power from the right engine during takeoff. The pilot stated that the engine power loss was not sudden, but rather a slow continued reduction of power. The pilot further stated that the loss of power occurred after he placed the landing gear selector in the retract position. He added that his airspeed at the time of the power loss was between Vmc (86 mph) and Vy (120 mph). The airplane started to roll towards the right (dead) engine as the pilot reduced the power on the left engine. The outboard portion of the right wing impacted the ground short of a taxiway. Examination of the wreckage revealed that the right engine propeller was in the feather position and the left engine was torn from the airframe. The reason for the loss of engine power was not determined.

Shortly after takeoff from Hamburg-Fuhlsbüttel Airport, while climbing, the pilot reported engine problems and was cleared to return for an emergency landing. While completing a turn, he lost control of the airplane that crashed in Niendorf, near the airport. The pilot, sole on board, was killed.

Immediately after take-off from London (Stansted) Airport, on a night flight with 30 passengers and 4 crew on board, an uncontained failure of the right engine occurred. This resulted in sudden power loss and a major engine bay fire. The commander elected to land back on the runway. The aircraft overran the paved surface, and uneven ground in the overrun area caused the nose landing gear to collapse. After the aircraft had come to rest, with the engine bay fire continuing, the crew organized a rapid evacuation and all the occupants escaped, with little or no injury. The engine bay fire was extinguished by the Airport Fire Service (AFS), but fuel release continued for some hours.

After takeoff from Toqui Airport, the pilot encountered poor visibility due to thick smoke coming from forest fire. While climbing, the single engine aircraft struck the slope of Mt Duida and crashed six minutes after takeoff. The wreckage was found few days later and all five occupants were killed, among them two US citizens and two Canadians.

The pilot stated he checked the fuel quantity in the inboard fuel tanks, but may have omitted the outboard tanks. He departed and climbed to 100 feet where the airplane yawed right. He believed it was a gust of wind which he attempted to correct. At 200 feet, the pilot stated the airplane rolled hard right and impacted trees in a 60 degree nose down attitude. There was no indication of a left engine discrepancy prior to impact. The right engine was examined with no fuel found in the fuel lines, and trace fuel was found in the fuel servo. According to the accident pilot, he regularly flew between Washington-Dulles and Southport, North Carolina using only the inboard tanks. Because of this, he did not check the location of the fuel selector, nor did he necessarily check the fuel quantity in the outboard fuel tanks. The cockpit fuel selector for the right engine was found in the outboard tank location. The right outboard tank on this airplane was not breached, and contained no fuel. The takeoff checklist states the fuel selector should be on the inboard fuel tank prior to takeoff.

During the takeoff roll, at a speed of 90 knots, the captain decided to abort. Unable to stop within the remaining distance, the aircraft overran and came to rest 270 metres further against an earth mound. All six occupants escaped with minor injuries and the aircraft was damaged beyond repair. The grassy runway used by the crew is 1,008 metres long and the last portion of 300 metres was waterlogged.

The cockpit voice recorder (CVR) recording indicated that the pilot was unable to start the right engine before takeoff, and elected to attempt takeoff with the right engine inoperative. Witnesses reported that the airplane's nose lifted off about 4,100 feet down the runway and that it then became airborne with its wings rocking, attaining a maximum altitude of 5 to 10 feet above the ground before settling back to the ground, departing the right side of the runway and entering an upright slide for about 1/2 mile. Investigators removed the right engine starter-generator from the engine after the accident and found the starter-generator drive shaft to be fractured. The aircraft has a minimum crew requirement of two, consisting of pilot and copilot; the copilot's seat occupant, a private pilot-rated passenger, did not hold a multiengine rating and thus was not qualified to act as second-in-command of the aircraft.

When the crew boarded the aircraft in Hsinchu for the flight to Kaohsiung it had been a long and demanding day for the captain who was to fly the aircraft. He had been on duty more than 11 hours and performed nine flights. The accident flight, which was planned to be his last flight of the day, was to take place in darkness. The weather was above minima but IMC. During the pre-flight check the crew noted a failure in the RH Main Bus. This caused a number of systems to be unavailable, a.o.: the autopilot, the left hand EFIS, LH/RH Flight Director, LH RMI, EFIS Comparators, and the no. 2 engine anti-ice start bleed valve being open (as a result of this, the ITT on this engine was approximately 15°C higher than normal at selected power on this engine). Despite the fact that, according to the Minimum Equipment List (MEL), taking off for a flight with any of the Main Buses inoperative was not allowed, the captain decided to continue. During taxi to runway 05 the aircraft was cleared for a Chunan One (CN1) departure. The aircraft took off at 19:29:09. Because of the autopilot was not available, the captain now had to fly manually. In addition, the flying had to be performed without support from the yaw-damper that was also inoperative as a result of the RH Main Bus failure. This means that more active rudder control was required, while the DFDR-data shows that such input was not made. The more than 30°C ITT-split between the engines, of which approximately 15°C was caused by the RH Engine Anti-ice Start Bleed Valve being open, did have little effect on the behavior of the aircraft in the initial start-sequence. But when the crew, 30 seconds after lift off, disengaged CTOT and started to manually adjust the RH PLA downwards, possibly to get equal ITT in the engines, this ended up in a torque-split of more than 13% between the engines, with the RH engine being lower in torque. This asymmetry tended to yaw and roll the aircraft to the right and required higher aileron input than normal to the left in order to keep the aircraft at a constant bank angle. Normally the flaps are retracted at around 1,000 feet during initial climb. In this flight the flap retraction was not initiated until the first officer was reading the Climb Check List in which the flap position should be checked and verified. Flap retraction was done just prior to the aircraft reaching VFE15 (175 KIAS, which is the maximum allowed speed with flaps extended). When the climb power was set, a symmetric PLA change was made. However, due to the earlier RH Power Lever Angle (PLA) pull in combination with the normal backlash in the power lever cables between the PLA and the HMU, the RH engine torque was decreased while the LH engine torque remained unchanged. Hence, a torque split occurred. This resulted in an increased aerodynamic asymmetry giving a force tending to yaw and bank the aircraft to the right. Consequently, still more aileron input was required in order to maintain a correct bank angle. Because the behavior of the aircraft was very different from what the captain was used to, the need for continuous manual flying under IMC-conditions may have totally occupied his capacity. This could also explain why, during this phase of flight, he did not observe the aircraft starting a turn to the right 78 seconds after take off instead of continuing the left turn for a heading of 260. At about this same time, and for no obvious reasons, the positive rate of climb decreased and the aircraft leveled out at approximately 2,000 feet for a short time instead of continuing the climb to its assigned altitude of 3,000 feet. The captain's actions could be interpreted as signs that he might have been suffering from fatigue or spatial disorientation. It is difficult to determine if the F/O was aware of the captain's deviation from the cleared departure route. All indications point to the fact that he was not aware or that he out of respect for the captain did not report of the deviations. For example, the F/O transmitted back to Taipei Approach 114 seconds after takeoff, "Left 230, Bravo 12255," while at the same time the aircraft was in a right turn with a 21 degree right bank, passing through a heading of 312 degrees. In fact, his primary means for monitoring the flight were very limited due to dark, IMC-conditions since his EFIS instruments were black or flagged. This could also explain why the captain did not receive any support from the F/O about the flight becoming more and more uncontrolled. Not until 124 seconds after takeoff and 37 seconds prior to the last DFDR-recording did the captain state that he was having a problem with the heading and asked for help with the magnetic compass. At that time the aircraft was in a 24° right bank and 10° pitch up position and had a heading and roll rate by one degree per second. From that moment a continuous decrease in pitch angle was recorded down to -65,4° just prior to the impact. Just 19 seconds before the last DFDR-recording, with a heading of 022 and a bank angle of 36° to the right, the captain said "Ask for a radar vector." At this moment, he also initiates a short aileron input to the right, further increasing the bank angle. The other crewmembers did not answer or give any notable response to the captain's request for help with the magnetic compass. The reason might be that they also were very confused about the situation and unable to take any relevant action. When the captain, 14 seconds before the last DFDR-recording, said "Wah Sei!!! Everything is wrong." the aircraft was in a 8,4° pitch down and the right bank angle was 47,5°. Finally, only 10 seconds before the last data point was recorded, the first officer responds by asking "Sir, shall we look at this one? ". Pitch down was then 15,8° and the right roll angle 71,7°. In the last part of the flight the pitch and bank angles were at extreme values not to be experienced in normal operation. At this stage of the flight, the control inputs recorded are rapid aileron inputs to the right that further increased the adverse attitudes. The aircraft was then totally uncontrolled and the airspeed and sink rate increased dramatically. Four seconds before impact the Vmo warning started. The aircraft then crashed into the sea.

During the takeoff roll at Mogadishu Airport, the crew lost control of the airplane that crashed in unknown circumstances. All four crew members were injured.