Takeoff (climb)

Findings as to Causes and Contributing Factors:
1. The combined effects of the atmospheric conditions and bank angle increased the load factor, causing an aerodynamic stall.
2. Due to the absence of a functioning stall warning system, in addition to the benign stalling characteristics of the Beaver, the pilot was not warned of the impending stall.
3. Because the aircraft was loaded in a manner that exceeded the aft CG limit, full stall recovery was compromised.
4. The altitude from which recovery was attempted was insufficient to arrest descent, causing the aircraft to strike the water.
5. Impact damage jammed 2 of the 4 doors, restricting egress from the sinking aircraft.
6. The pilot’s seat failed and he was unrestrained, contributing to the seriousness of his injuries and limiting his ability to assist passengers.
Findings as to Risk:
1. There is a risk that pilots will inadvertently stall aircraft if the stall warning system is unserviceable or if the audio warnings have been modified to reduce noise levels.
2. Pilots who do not undergo underwater egress training are at greater risk of not escaping submerged aircraft.
3. The lack of alternate emergency exits, such as jettisonable windows, increases the risk that passengers and pilots will be unable to escape a submerged aircraft due to structural damage to primary exits following an impact with the water.
4. If passengers are not provided with explicit safety briefings on how to egress the aircraft when submerged, there is increased risk that they will be unable to escape following an impact with the water.
5. Passengers and pilots not wearing some type of flotation device prior to an impact with the water are at increased risk of drowning once they have escaped the aircraft.

The crew did not properly operate the thrust levers so that the engines did not reach take off thrust. The aircraft had not reached Vr at the end of the runway and could not get airborne. According to the design criteria of the MD11 the crew needs to push at least two thrust levers to beyond 60 degrees, which will trigger autothrust to leave "CLAMP" mode and adjust the thrust to reach the target setting for takeoff, the servo motors would push the thrust levers forward in that case. During the accident departure the pilot in the left seat did not advance the thrust levers to more than 60 degrees, hence the server motors did not work although autothrust was engaged but remained in CLAMP mode and thus did not adjust the thrust to reach takeoff settings. The crew members perceived something was wrong. Audibly the engine sound was weak, visibibly the speed of the aircraft was low, tactically the pressure on the back of the seat was weaker than normal. Somebody within the crew, possibly on the observer seats, suggested the aircraft may be a bit heavy. The T/O THRUST page never appeared (it appears if autothrust is engaged and changes from CLAMP to Thrust Limit setting. Under normal circumstances with autothrust being engaged a click sound will occur as soon as the thrust levers reach the takeoff thrust position. A hand held on the thrust levers will feel the lever moving forward, however, the crew entirely lost situational awareness. None of the anomalies described in this paragraph prompted the crews members' attention. When the aircraft approached the end of the runway several options were available: reject takeoff and close the throttles, continue takeoff and push the throttle to the forward mechanical stop, continue takeoff and immediately rotate. The observer called "rotate", the captain rotated the aircraft. This shows the crew recognized the abnormal situation but did not identify the error (thrust levers not in takeoff position) in a hurry but reacted instinctively only. As the aircraft had not yet reached Vr, the aircraft could not get airborne when rotated. As verified in simulator verification the decision to rotate was the wrong decision. The simulator verification showed, that had the crew pushed the thrust levers into maximum thrust when they recognized the abnormal situation, they would have safely taken the aircraft airborne 670 meters before the end of the runway. The verification also proved, that had the crew rejected takeoff at that point, the aircraft would have stopped before the end of the runway. The crew did not follow standard operating procedures for managing thrust on takeoff. The crew operations manual stipulates that the left seat pilot advances the thrust levers to EPR 1.1 or 70% N1 (depending on engine type), informs the right seat pilot to connect autothrust. The pilot flying subsequently pushes the thrust levers forward and verifies they are moving forward on servos, the pilot monitoring verifies autothrust is working as expected and reaches takeoff thrust settings. In this case the left seat pilot not only did not continue to push the thrust levers forward, but also called out "thrust set" without reason as he did not verify the takeoff thrust setting had been achieved. It is not possible to subdivide the various violations of procedures and regulations. The crew had worked 16 hours during the previous sector. In addition, one crew member needed to travel for 11 hours from Europe to reach the point of departure of the previous sector (Nairobi Kenya), two crew members need to travel for 19 hours from America to the point of departure of the previous sector. These factors caused fatigue to all crew members. The co-pilot was 61 years of age, pathological examination showed he was suffering from hypertension and cardiovascular atherosclerosis. His physical strength and basic health may have affected the tolerance towards fatigue. All crew members underwent changes across multiple time zones in three days. Although being in the period of awakeness in their biological rhythm cycle, the cycle was already in a trough period causing increased fatigue. The captain had flown the Airbus A340 for 300 hours in the last 6 months, which has an entirely different autothrust handling, e.g. the thrust levers do not move with power changes in automatic thrust, which may have caused the captain to ignore the MD-11 thrust levers. The co-pilot in the right hand seat had been MD-11 captain for about 7 years but had not flown the MD-11 for a year. Both were operating their first flight for the occurrence company. The two pilots on the observer seats had both 0 flight hours in the last 6 months. The co-pilot (right hand seat) was pilot flying for the accident sector. The captain thus was responsible for the thrust management and thrust lever movement according to company manual. A surviving observer told the investigation in post accident interviews that the captain was filling out forms and failed to monitor the aircraft and first officer's actions during this critical phase of flight. There are significant design weaknesses in the MD-11 throttle, the self checks for errors as well as degree of automation is not high.
Source: Aviation Herald/Simon Hradecky

The investigations revealed that during this operation the aircraft's take-off weight was exceeded by 629 pounds. The aircraft failed to maintain flying speed and stalled shortly after takeoff, rendering ground impact inevitable.
The following contributing factors were identified:
- This was the pilot's first flight from Eros Airport therefore being unfamiliar with the airport and the environmental phenomena's associated with it (especially taking off from runway 19),
- The pilot made one fundamental error in his weight calculation that he used the incorrect aircraft empty weight,
- The cargo that was in the cabin was packed between and underneath and on top of the seats and was not secured,
- The aircraft took off from runway 19, which was an upslope runway,
- Taking off from runway 19 the terrain kept rising with mountains straight ahead as well as to the left and right,
- The pilot retracted the flaps shortly after rotation, which resulted in an attitude change and performance (aircraft lost altitude), which should be regarded as a significant contributory factor to this accident,
- The pilot was observed to turn to the right shortly after takeoff, which increased the drag on the aircraft as well as the stall speed,
- Harsh anti-erosion rubber paint that was sprayed onto the leading edge of the wings resulted in an increased stall speed,
- Inadequate oversight by the regulatory authority should be regarded as a significant contributory factor to this accident.

The engine n°3 detached during the takeoff roll for unknown reasons.

A total loss of left engine power and subsequent failure of the airplane to maintain airspeed and altitude on the remaining engine for undetermined reasons.

Loss of control during takeoff following a collision with five warthogs.

The day before the accident, the aircraft arrived in Mirny following a cargo flight, delivering various goods. After landing, the crew activated the electrical locking system for the rudder and the ailerons, and the 'lock on' light came on in the cockpit panel. In the morning of the accident, prior to takeoff, the crew followed the pre-takeoff checklist and deactivated the electrical locking system, but the 'lock on' light remained illuminated. Considering this as a false alarm, the captain decided to take off and proceeded with a manuel control of the ailerons. The left aileron moved normally while the right aileron got locked because of the locking mechanism. During the takeoff roll, because the four engine were not in full power mode, there was no sound alarm about the aileron locked mechanism. The aircraft deviated to the right and after lift off, it rolled to the right to angle of 8°. The pilot-in-command elected to counteract the banking but this maneuver was limited due to the right aileron locked mechanism. The aircraft continued to roll to the right to an angle of 90° until control was lost.

The Investigation identified the following Causes:
(a) the departure of the No. 4 engine core cowls;
(b) the consequent disconnection of No. 4 engine EPR Pt7 flex line;
(c) the probable inappropriate crew response to the perceived No. 4 engine power loss;
(d) the Aircraft entering into a stall after the published maximum bank angle was exceeded; and
(e) the Aircraft Loss of Control (“LOC”) that was not recoverable.

Contributing Factors to the Accident were:
(a) the Aircraft was not properly maintained in accordance with the Structure Repair
Manual where the cowls had gone through multiple skin repairs that were not up to
aviation standards;
(b) the Operator’s maintenance system failure to correctly address the issues relating to the No. 4 engine cowls failure to latch issues;
(c) the failure of the inspection and maintenance systems of the maintenance organization, which performed the last C-Check, to address, and appropriately report, the damage of the No. 4 engine cowls latches prior to issuing a Certificate of Release to Service;
(d) the Operator’s failure to provide a reporting system by which line maintenance personnel report maintenance deficiencies and receive timely and appropriate guidance and correction actions;
(e) the Operator’s quality system failure to adequately inspect and then allow repairs that were of poor quality or were incorrectly performed to continue to remain on the Aircraft; and
(f) the SCAA safety oversight system deficiency to adequately identify the Operator’s chronic maintenance, operations and quality management deficiencies.

Technical or medical problems could not be ruled out according to Dutch Safety Board. However, it was considered likely that the pilot suffered from spatial disorientation.
Factors were:
- the fact that the autopilot disengaged;
- the high work load following loss of autopilot, during a single-pilot flight;
- the lack of training and experience on advanced aircraft like the PC-12 in manually flying the aircraft in IMC in a non-normal situation.