Let L-410

According to the findings of the commission of inquiry, the most likely cause of the crash was the impact of the aircraft in a low-altitude wind due to strong downward air flow (micro-burst) during the landing of the aircraft in thunderstorms due to coincidence of the following negative factors.
- Failure of the crew to perform a go around or divert to the alternate aerodrome;
- A rapid increase in the speed of movement of the thunderstorm in the direction of the Borodyanka airfield area;
- Lack of training on the simulator in the conditions of wind shear, lack of experience in the crew on approach to landing in the conditions of wind shear, in particular micro-burst;
- Insufficient aeronautical equipment (lack of meteorological radar on the plane and airfield);
- Lack of information for the crew about the forecasted and actual meteorological conditions at the landing aerodrome, warnings about the forecasted / available wind shift at Borodyanka aerodrome;
- The crew was not sufficiently informed about the flight conditions due to insufficient lighting of the cockpit and failure of the instrumentation of the aircraft due to a power failure during approach in thunderstorm conditions;
- Lack of sufficient experience of the crew to perform activities and landings in conditions when the landing weight exceeded the maximum allowable, due to the presence of skydivers on board the aircraft;
- Motivation of the crew to perform the landing approach on the first attempt, due to insufficient information about the storm at the aerodrome. The information on wind increase and its direction (provided to the pilot) was perceived by the crew as possible conditions for landing because their parameters did not exceed the limits allowed by the AOM of the aircraft;
- Overloading of the aircraft, motivation of the decision of the captain to perform landing at the aerodrome of departure (Borodyanka) due to the presence of unregistered passengers on board, due to improper organization of boarding of skydivers at the aerodrome Borodyanka;
- Insufficient organization of flights at Borodyanka airfield in terms of meteorological support;
- Insufficient (weak) regulatory, regulatory, legislative framework for parachuting.

Human Factors
Medical Aspect
- Anxiety
The perception of danger especially by the first officer affected the communication between the pilots and may have inhibited a more assertive attitude, which could have led to an emergency landing on the beach, minimizing the consequences of the accident.
Psychological Aspect
- Attitude
Operational decisions during the emergency may have resulted from the high confidence level, that the captain had acquired in years of flying and experience in aviation, as well as the captain's resistance to accept opinions different to his own.
- Emotional state
According to CVR recordings there was a high level of anxiety and tension even before the abnormal situation. These components may have influenced the judgment of conditions affecting the operation of the aircraft.
- Decision making
The persistence to land on runway 36 during the emergency, even though the first officer recognized the conditions no longer permitted to reach the airport, reflects misjudgment of operational information present at the time.
- Signs of stress
The unexpected emergency at takeoff and the lack of preparation for dealing with it may have invoked a level of stress with the crew, that negatively affected the operational response.
Psychosocial Information
- Interpersonal relations
The historical differences between the two pilots possibly hindered the exchange of information and created a barrier to deal with the adverse situation.
- Dynamic team
The present diverging intentions of how to proceed clearly show cooperation and management issues in the cockpit. This prevented the choice of best alternative to achieve a safe emergency landing when there were no options left to reach the airport.
- Company Culture
The company was informally divided into two groups, whose interaction was impaired. It is possible that this problem of interaction continued into the cockpit management during the in flight emergency, with one pilot belonging to one and the other to the other group.
Organizational Information
- Education and Training
Deficiencies of training provided by the operator affected the performance of the crew, who had not been sufficiently prepared for the safe conduct of flight in case of emergency.
- Organizational culture
The actions taken by the company indicate informality, which resulted in incomplete operational training and attitudes that endangered the safety.
Operational Aspects
According to data from the flight recorder the rudder pedal inputs were inadequate to provide sufficient rudder deflection in order to compensate for asymmetric engine power.
The values of side slip reached as result of inadequate rudder pedal inputs penalized the performance of the aircraft preventing further climb or even maintaining altitude.
In the final phase of the flight, despite the airspeed decaying below Vmca, despite continuous stall warnings and despite calls by the first officer to not hold the nose up in order to not stall the captain continued pitch up control inputs until the aircraft reached 18 degrees nose up attitude and entered stall.
- Crew Coordination
The delay in retracting the landing gear after the first instruction by the captain, the instruction of the captain to feather the propeller when the propeller had already been feathered as well as the first officer's request the captain should initiate the turn back when the aircraft was already turning are indicative that the crew tasks and actions were not coordinated.
Emergency procedures provided in checklists were not executed and there was no consensus in the final moments of the flight, whether the best choice (least critical option) was to return to the runway or land on the beach.
- Oblivion
It is possible in response to the emergency and influenced by anxiety, that the crew may have forgotten to continue into the 3rd segment of the procedure provided for engine failure on takeoff at or above V1 while trying to return to the airfield shortly after completion of the 2nd segment while at 400ft.
- Pilot training
The lack of training of engine failures on takeoff at or above V1, similar as is recommended in the training program, led to an inadequate pilot response to the emergency. The pilots did not follow the recommended flight profile and did execute the checklist items to be carried out above 400 feet.
- Pilot decisions
The pilots assessed that the priority was to return to land in opposite direction of departure and began the turn back at 400 feet, which added to the difficulty of flying the aircraft. At 400 feet the aircraft maintained straight flight and a positive rate of climb requiring minor flight control inputs only, which would have favored the completion of the emergency check list items in accordance with recommendations by the training program.
After starting the turn the crew would needed to adjust all flight controls to maintain intended flight trajectory in addition to working the checklists, the turn thus increased workload. It is noteworthy that the remaining engine developed sufficient power to sustain flight.
- Supervision by Management
The supervision by management did not identify that the training program provided to pilots failed to address engine failure above V1 while still on the ground and airborne.
It was not identified that the software adopted by the company to dispatch aircraft used the maximum structural weight (6,600 kg) as maximum takeoff weight for departures from Recife.
On the day of the accident the aircraft was limited in takeoff weight due to ambient temperature. Due to the software error the aircraft took off with more than the maximum allowable takeoff weight degrading climb performance.
Mechanical Aspects
- Aircraft
Following the hypothesis that the fatigue process had already started when the turbine blade was still attached to the Russia made engine, the method used by the engine manufacturer for assessment to continue use of turbine blades was not able to ensure sufficient quality of the blade, that had been mounted into position 27 of the left hand engine's Gas Generator Turbine's disk.
- Aircraft Documentation
The documentation of the aircraft by the aircraft manufacturer translated into the English language did not support proper operation by having confusing texts with different content for the same items in separate documents as well as translation errors. This makes the documentation difficult to understand, which may have contributed to the failure to properly implement the engine failure checklists on takeoff after V1.
An especially concerning item is the "shutdown ABC (Auto Bank Control)", to be held at 200 feet height, the difference between handling instructed by the checklist and provided by the flight crew manual may have contributed to the non-performance by the pilots, aggravating performance of the aircraft.

The following findings were identified:
1) Weather conditions existing at the time of the event, during the approach to the runway the aircraft was operated slightly above the stall speed and a major change in wind speed could cause a stall. The altitude at which the windshear occurred, and the reaction time of the pilot and the responsiveness of the aircraft determined whether the descent could be arrested in time to avoid an accident.
2) No published descent procedures were performed, possibly misinterpretation of Flight Instruments (altimeter, airspeed indicator).
3) During the descent to the VOR/DME for runway 20 and 02, the pilot in command (PIC) did not check his approach chart, and did not continually consult the first officer on the altitude and course.
4) There was no adequate communication between crew; deficient CRM (No approach briefing was made for any of the two approaches).
5) The aircraft was configured for landing with flaps fully down (flap 42) at a very long distance from the track without having it in sight. It is noteworthy that the aircraft will not respond to an adverse condition windshear as it appeared at that time with such a configuration. It should be noted that in both approaches it is mandatory to perform a 'circling' procedure.

It is believed that the accident was the consequence of an engine failure.

Loss of control on final approach due to the movement of several passengers in the cabin, panicked by the presence of a crocodile.