Takeoff (climb)

The pilot reported that the airplane "hesitated" during the takeoff roll due to the added weight of the passengers on board and the grass surface of the departure airstrip (Jim Finlay Farm Airstrip). He said he then added "extra" engine power at rotation, and that the left engine accelerated more quickly than the right, which resulted in an adverse yaw to the right and collision with trees along the right side of the runway. The subsequent collision with trees and terrain resulted in substantial damage to the airframe. According to the pilot, there were no mechanical deficiencies with the airplane that would have prevented normal operation.

During takeoff to the east over the ocean, after the twin-engine jet climbed straight ahead to about 2,200 ft and 200 knots groundspeed, the copilot requested radar vectors back to the departure airport due to an "engine failure." The controller assigned an altitude and heading, and the copilot replied, "not possible," and requested a 180-degree turn back to the airport, which the controller acknowledged and approved. However, the airplane continued a gradual left turn to the north as it slowed and descended. The copilot subsequently declared a "mayday" and again requested vectors back to the departure airport. During the next 3 minutes, the copilot requested, received, and acknowledged multiple instructions from the controller to turn left to the southwest to return to the airport. However, the airplane continued its slow left turn and descent to the north. The airplane slowed to 140 knots and descended to 900 ft as it flew northbound, parallel to the shoreline, and away from the airport. Eventually, the airplane tracked in the direction of the airport, but it continued to descend and impacted the ocean about 1 mile offshore. According to conversations recorded on the airplane's cockpit voice recorder (CVR), no checklists were called for, offered, or used by either flight crewmember during normal operations (before or during engine start, taxi, and takeoff) or following the announced in-flight emergency. After the "engine failure" was declared to the air traffic controller, the pilot asked the copilot for unspecified "help" because he did not "know what's going on," and he could not identify the emergency or direct the copilot in any way with regard to managing or responding to the emergency. At no time did the copilot identify or verify a specific emergency or malfunction, and he did not provide any guidance or assistance to the pilot. Examination of the recovered wreckage revealed damage to the left engine's thrust reverser components, including separation of the lower blocker door, and the stretched filament of the left engine's thrust reverser "UNLOCK" status light, which indicated that the light bulb was illuminated at the time of the airplane's impact. Such evidence demonstrated that the left engine's thrust reverser became unlocked and deployed (at least partially and possibly fully) in flight. Impact damage precluded testing for electrical, pneumatic, and mechanical continuity of the thrust reverser system, and the reason the left thrust reverser deployed in flight could not be determined. No previous instances of the inflight deployment of a thrust reverser on this make and model airplane have been documented. The airplane's flight manual supplement for the thrust reverser system contained emergency procedures for responding to the inadvertent deployment of a thrust reverser during takeoff. For a deployment occurring above V1 (takeoff safety speed), the procedure included maintaining control of the airplane, placing the thrust reverser rocker switch in the "EMER STOW" position, performing an engine shutdown, and then performing a single-engine landing. Based on the wreckage evidence and data recovered from the left engine's digital electronic engine control (DEEC), the thrust reverser rocker switch was not placed in the "EMER STOW" position, and the left engine was not shut down. The DEEC data showed a reduction in N1 about 100 seconds after takeoff followed by a rise in N1 about 35 seconds later. The data were consistent with the thrust reverser deploying in flight (resulting in the reduction in N1) followed by the inflight separation of the lower blocker door (resulting in the rise in N1 as some direct exhaust flow was restored). Further, the DEEC data revealed full engine power application throughout the flight. Although neither flight crewmember recognized that the problem was an inflight deployment of the left thrust reverser, certification flight test data indicated that the airplane would have been controllable as it was configured on the accident flight. If the crew had applied the "engine failure" emergency procedure (the perceived problem that the copilot reported to the air traffic controller), the airplane would have been more easily controlled and could have been successfully landed. The airplane required two fully-qualified flight crewmembers; however, the copilot was not qualified to act as second-in-command on the airplane, and he provided no meaningful assistance to the pilot in handling the emergency. Further, although the pilot's records indicated considerable experience in similar model airplanes, the pilot's performance during the flight was highly deficient. Based on the CVR transcript, the pilot did not adhere to industry best practices involving the execution of checklists during normal operations, was unprepared to identify and handle the emergency, did not refer to the appropriate procedures checklists to properly configure and control the airplane once a problem was detected, and did not direct the copilot to the appropriate checklists.

The crew was performing a night mail flight from Paris-Roissy-CDG Airport to Dole-Jura (Tavaux) Airport on behalf of Europe Airpost. Shortly after takeoff, while climbing to an altitude of 1,000 feet, the left propeller detached and impacted the left part of the fuselage, causing a large hole. The crew declared an emergency and was cleared for an immediate return. The aircraft landed safely less than 10 minutes later and was parked on the apron. Both pilots were uninjured and the aircraft was damaged beyond repair. The propeller was found in an open field in Mesnil-Amelot, near the airport. Nobody on ground was injured.

On 19 October 2013, an Avions de Transport Régional ATR42-320 freighter, registered P2-PXY (PXY) and operated by Air Niugini, was scheduled to fly from Madang to Tabubil, Western Province, as flight PX2900 carrying a load tobacco for a client company. There were three persons on board; the pilot in command (PIC), a copilot, and a PNG experienced DHC-8 captain whose function was to provide guidance during the approach into Tabubil. The PIC was the handling pilot and the copilot was the support monitoring pilot. The flight crew taxied to the threshold end of runway 25 intending to use the full length of the runway. The take-off roll was normal until the PIC tried to rotate at VR (speed for rotation, which the flight crew had calculated to be 102 knots). He subsequently reported that the controls felt very heavy in pitch and he could not pull the control column back in the normal manner. Flight data recorder (FDR) information indicated that approximately 2 sec later the PIC aborted the takeoff and selected full reverse thrust. He reported later that he had applied full braking. It was not possible to stop the aircraft before the end of the runway and it continued over the embankment at the end of the runway and the right wing struck the perimeter fence. The aircraft was substantially damaged during the accident by the impact, the post-impact fire and partial immersion in salt water. The right outboard wing section was completely burned, and the extensively damaged and burnt right engine fell off the wing into the water. Both propellers were torn from the engine shafts and destroyed by the impact forces.

The single engine aircraft was engaged in a charter flight from Likawage to Dar es Salaam, carrying one passenger and two pilots. Ready for takeoff at threshold, the crew applied full power and maintained brakes. Despite the engine did not reach the takeoff power, the captain released brakes and initiated the takeoff roll. The aircraft rolled for about three-quarters of the runway when the engine reached the takeoff power. But the aircraft failed to rotate, continued, overran and eventually collided with trees, bursting into flames. All three occupants were slightly injured and the aircraft was partially destroyed by fire.

The crew discussed some concerns about the aircraft prior to departure but at this time we are not prepared to elaborate on those concerns as there remains a lot of work to complete on the CVR analysis in order to determine the specific nature of the crew’s concerns. Associated 361 was cleared for take-off on runway one eight left at Lagos international airport. The wind was calm and weather is not considered a factor in this accident. Approximately 4 seconds after engine power was advanced to commence the take-off roll, the crew received an automated warning from the onboard computer voice which consisted of three chimes followed by “Take-off Flaps…Take-off Flaps”. This is a configuration warning that suggests that the flaps were not in the correct position for take-off and there is some evidence that the crew may have chosen not to use flaps for the take-off. The warning did not appear to come as any surprise to the crew and they continued normally with the take-off. This warning continues throughout the take-off roll. As we are in the process of verifying the accuracy of the flight data, we have not yet been able to confirm the actual flap setting however we expect to determine this in the fullness of time. It was determined from the CVR that the pilot flying was the Captain and the pilot monitoring and assisting was the First Officer. The ‘set power‘ call was made by the Captain and the ‘power is set’ call was confirmed by the First Officer as expected in normal operations. Approximately 3 seconds after the ‘power is set’ call, the First Officer noted that the aircraft was moving slowly. Approximately 7 seconds after the ‘power is set’ call, the internal Aircraft Voice warning system could be heard stating ‘Take off Flaps, Auto Feather’. Auto feather refers to the pitch of the propeller blades. In the feather position, the propeller does not produce any thrust. The FDR contains several engine related parameters which the AIB is studying. At this time, we can state that the Right engine appears to be producing considerably less thrust than the Left engine. The left engine appeared to be working normally. The aircraft automated voice continued to repeat ‘Take-off Flaps, Auto Feather’. The physical examination of the wreckage revealed that the right engine propeller was in the feather position and the engine fire handle was pulled/activated. The standard ‘eighty knots’ call was made by the First Officer. The first evidence that the crew indicated that there was a problem with the take-off roll was immediately following the ‘eighty knots’ call. The First Officer asked if the take- off should be aborted approximately 12 seconds after the ‘eighty knots’ callout. Our investigation team estimates the airspeed to be approximately 95 knots. Airspeed was one of the parameters that, while working in the cockpit, appeared not to be working on the Flight Data Recorder. We were able to estimate the speed based on the radar data that we synchronized to the FDR and CVR but it is very approximate because of this. In response to the First Officer’s question to abort, the Captain indicated that they should continue and they continued the take-off roll. The crew did not make a ‘V1’ call or a Vr’ call. V1 is the speed at which a decision to abort or continue a take-off is made. Vr is the speed at which it is planned to rotate the aircraft. Normally the non-flying pilot calls both the V1 and the Vr speeds. When Vr is called the flying pilot pulls back on the control column and the aircraft is rotated (pitched up) to climb away from the runway. During the rotation, the First Officer stated ‘gently’, which we believe reflects concern that the aircraft is not performing normally and therefore needs to be rotated very gently so as not to aerodynamically stall the aircraft. The First Officer indicated that the aircraft was not climbing and advised the Captain who was flying not to stall the aircraft. Higher climb angles can cause an aerodynamic stall. If the aircraft is not producing enough overall thrust, it is difficult or impossible to climb without the risk of an aerodynamic stall. Immediately after lift-off, the aircraft slowly veered off the runway heading to the right and was not climbing properly. This aircraft behavior appears to have resulted in the Air Traffic Controller asking Flight 361 if operation was normal. Flight 361 never responded. Less than 10 seconds after rotation of the aircraft to climb away from the runway, the stall warning sounded in the cockpit and continued to the end of the recording. The flight data shows characteristics consistent with an aerodynamic stall. 31 seconds after the stall warning was heard, the aircraft impacted the ground in a nose down near 90° right bank.

After takeoff from runway 34 at Lyon-Bron Airport, while in initial climb at a height of 200 feet, the twin engine airplane deviated to the left, rolled to the left and then veered to the left with a low rate of climb. Shortly after passing the end of the runway, the airplane lost height then struck the ground and caught fire. The airplane was destroyed by a post crash fire and all four occupants were killed. For unknown reasons, the pilot-in-command was seating in the right seat.

The pilot reported that he performed the takeoff with the airplane at gross weight and with the flaps up and the engine set for maximum power, which he verified by reading the instruments. During the takeoff, the airplane accelerated and achieved liftoff about 65 to 70 mph and then climbed a couple hundred feet before the pilot began to lower the nose to accelerate to normal climb speed (90 to 100 mph). The airplane then stopped climbing and would not accelerate more than 80 mph. While the pilot attempted to maintain altitude, the airplane decelerated to 70 mph with the engine still at the full-power setting. With insufficient runway remaining to land, the pilot made a shallow right turn toward lower terrain and subsequently made a hard landing in a field. The pilot likely allowed the airplane to climb out of ground effect before establishing a proper pitch attitude and airspeed for the climb, which resulted in the airplane inadvertently entering a “region of reversed command” at a low altitude. In this state, the airplane may be incapable of climbing and would require either more engine power or further lowering of the airplane’s nose to increase airspeed. Because engine power was already at its maximum and the airplane was at a low altitude, the pilot was unable to take remedial action to fly out of the region of reversed command.

Company personnel reported that, in the weeks before the accident, the airplane's left engine had been experiencing a problem that prevented it from initially producing 100 percent power. The accident pilot and maintenance personnel attempted to correct the discrepancy; however, the discrepancy was not corrected before the accident flight, and company personnel had previously flown flights in the airplane with the known discrepancy. Witnesses reported observing a portion of the takeoff roll, which they described as slower than normal. However, the airplane was subsequently blocked from their view. Examination of the runway environment showed that, during the takeoff roll, the airplane traveled the entire length of the 4,501-ft runway, continued to travel through a 300-ft-long grassy area and a 300- ft-long soybean field, and then impacted the top of 10-ft-tall corn stalks for about 50 ft before it began to climb. About 1/2 mile from the airport, the airplane impacted several trees in a leftwing, nose-low attitude, consistent with the airplane being operated below the minimum controllable airspeed. The main wreckage was consumed by postimpact fire. Postaccident examinations revealed no evidence of mechanical anomalies with the airframe, right engine, or propellers that would have precluded normal operation. Given the left engine's preexisting condition, it is likely that its performance was degraded; however, postimpact damage and fire preluded a determination of the cause of the problem.

According to the pilot, he applied full power, set the flaps at 10 degrees, released the brakes, and, after reaching 80 knots, he rotated the airplane. The pilot further reported that the engine subsequently lost total power when the airplane was about 150 ft above ground level. The airplane then impacted water in a nose-down, right-wing-low attitude about 300 ft from the end of the runway. The pilot reported that he thought that the runway was 1,900 ft long; however, it was only 1,300 ft long. Review of the takeoff ground roll distance charts contained in the Pilot’s Operating Handbook (POH) revealed that, with flap settings of 0 and 20 degrees, the ground roll would have been 1,700 and 1,150 ft, respectively. Takeoff ground roll distances were not provided for use of 10 degrees of flaps; however, the POH stated that 10 degrees of flaps could be used. Although the distance was not specified, it is likely that the airplane would have required more than 1,300 ft for takeoff with 10 degrees of flaps. Examination of the engine revealed saltwater corrosion throughout it; however, this was likely due to the airplane’s submersion in water after the accident. No other mechanical malfunctions or abnormalities were noted. Examination of data extracted from the multifunction display (MFD) and primary flight display (PFD) revealed that the engine parameters were performing in the normal operating range until the end of the recordings. The data also indicated that, 7 seconds before the end of the recordings, the airplane pitched up from 0 to about 17 degrees and then rolled 17 degrees left wing down while continuing to pitch up to 20 degrees. The airplane then rolled 77 degrees right wing down and pitched down about 50 degrees. The highest airspeed recorded by the MFD and PFD was about 70 knots, which occurred about 1 second before the end of the recordings. The POH stated that, depending on the landing gear position, flap setting, and bank angle, the stall speed for the airplane would be between 65 and 71 knots. Based on the evidence, it is likely that the engine did not lose power as reported by the pilot. As the airplane approached the end of the runway and the pilot realized that it was not long enough for his planned takeoff, he attempted to lift off at an insufficient airspeed and at too high of a pitch angle, which resulted in an aerodynamic stall at a low altitude. If the pilot had known the actual runway length, he might have used a flap setting of 20 degrees, which would have provided sufficient distance for the takeoff.