Takeoff (climb)

Failure of the left engine just after liftoff for unknown reasons.

The reason for the loss of engine power in flight, most likely, was a reduction in the filing of the gasoline due to clogging of fuel filters. The appearance, structure and nature of the impurities found in the fuel on the aircraft were not characteristic of impurities accumulated in the fuel supply system in normal operating conditions. The source of the impurities in aircraft fuel system could not be found.

The flight instructor’s decision to attempt a touch-and-go landing toward rising terrain and with a tailwind, resulting in an in-flight collision with terrain during takeoff.

The following factors were identified:
- Lack of available thrust which corresponded to the power of only two engines running during take off run,
- Lack of authorized maintenance of the aircraft,
- The uncoordinated crew actions in the critical situation (both pilots had previously flown as captains). The lack of coordination is confirmed by the braking trails left by the main landing gear at the end of RWY -02, based on FCOM instructions, and in case of rejected takeoff attempt, the crew had to set the throttles to idle, lower the nose gear to reach the runway and then use the propellers for braking (releasing them from the stops). Also, to reduce the roll and to maintain the direction they were to use the nose wheel steering and wheel brakes as well as emergency braking if needed. Actually the crew did neither of the above procedures, except using the main wheel brakes.

Engine failure for unknown reasons.

The cause of the accident was due to an impact with the ground resulting from the loss of control of the aircraft by the captain, who was also the PF. It appears very likely that during the initial phase inadequate attention was replaced by a phase of spatial disorientation, resulting in a loss of situational awareness, which prompted an inadequate intervention on the flight controls by the PF, resulting in total loss of control of the aircraft (having accentuated the tilt to the left wing, instead of leveling the aircraft). It is reasonable to assume that the PF, based on the conviction of being in a right turn for Bolsena in IMC night conditions, misinterpreted the unusual turn, using the controls in order to accentuate the bank angle to the left, drastically reducing the vertical component of lift. This turn has consequently caused the aircraft to assume an attitude of increasing bank, a condition that has been aggravated by the continued application on the controls of a positive load factor in order to stop the sudden loss of altitude, without first leveling the wings. Or the aircraft is stabilized in a pronounced downward spiral to the left. The first officer (PNF), engaged in the management of navigation equipment, has created the unusual turn of the aircraft in conjunction with the commander (PF). Nevertheless, the considerable gradient of experience on the airplane and hierarchy within the organization between the captain and the first officer has probably prevented him to intervene in a more directive or authoritative way in the recovery phase of the situation. Also contributing to the outcome of the event was the lack of detail in the definition of the duties of the crew procedures and inadequate adherence to the basic principles of CRM/MCC, with reference to the monitoring and statement of the navigation modes active, navigation procedures and in particular to the lack of requests for inclusion of turns and routes, the deficiency in the performance of controls and optimization of automation that can lighten the workload in a time unfavorable from the point of view of the circadian rhythm and IMC night. In this respect, it seems fitting to remember the problem of spatial disorientation, although known and studied for decades, is still relevant, and that the only way to counter it is the application of proper use of instruments in compliance with the basic principles of CRM/MCC, which should be part of the normal operating procedures of an operator. This is especially true when working outside of normal circadian rhythms, when it is most easily seen a slowing of cognitive processes.

Findings as to Causes and Contributing Factors:
1. Contamination on the wings of the aircraft was not fully removed before take-off. It is likely that asymmetric contamination of the wings created a lift differential and a loss of lateral control.
2. Although the operator was not authorized for short take-off and landing (STOL) take-off on this aircraft, the crew conducted a STOL take-off, which reduced the aircraft’s safety margin relative to its stalling speed and minimum control speed.
3. As a result of the loss of lateral control, the slow STOL take-off speed, and the manipulation of the flaps, the aircraft did not remain airborne and veered right, colliding with obstacles beside the ski strip.
Findings as to Risk:
1. The out of phase task requirements regarding the engine vibration isolator assembly, as listed in the operator’s maintenance schedule approval, results in a less than thorough inspection requirement, increasing the likelihood of fatigue cracks remaining undetected.
2. The right engine inboard and top engine mounts had pre-existing fatigue cracks, increasing the risk of catastrophic failure.
Other Findings:
1. The cockpit voice recorder (CVR) contained audio of a previous flight and was not in operation during the occurrence flight. Minimum equipment list (MEL) procedures for logbook entries and placarding were not followed.
2. The Transwest Air Limited safety management system (SMS) did not identify deviations from standard operating procedures.

The student pilot failed to follow the checklist and set the takeoff trim properly prior to takeoff resulting in a loss of directional control. Contributing to the accident were the certified flight instructor's inadequate supervision and delayed remedial action.