Landing (descent or approach)

Findings as to causes and contributing factors:
1. The pilot's decision to conduct an approach to an aerodrome not serviced by an instrument flight rules approach in adverse weather conditions was likely the result of the pilot's inexperience, and may have been influenced by the pilot's desire to successfully complete the flight.
2. The pilot's decision to descend into cloud and continue in icing conditions was likely the result of inadequate awareness of the Piper PA31-350 aircraft's performance in icing conditions and of its de-icing capabilities.
3. While waiting for the runway to be cleared of snow, the aircraft held near North Spirit Lake (CKQ3) in icing conditions. The resulting ice accumulation on the aircraft's critical surfaces would have led to an increase in the aircraft's aerodynamic drag and stall speed, causing the aircraft to stall during final approach at an altitude from which recovery was not possible.
Findings as to risk:
1. Terminology contained in aircraft flight manuals and regulatory material regarding “known icing conditions,” “light to moderate icing conditions,” “flight in,” and “flight into” is inconsistent, and this inconsistency increases the risk of confusion as to the aircraft’s certification and capability in icing conditions.
2. If confusion and uncertainty exist as to the aircraft’s certification and capability in icing conditions, then there is increased risk that flights will dispatch into icing conditions that exceed the capability of the aircraft.
3. The lack of procedures and tools to assist pilots in the decision to self-dispatch leaves them at increased risk of dispatching into conditions beyond the capability of the aircraft.
4. When management involvement in the dispatch process results in pilots feeling pressure to complete flights in challenging conditions, there is increased risk that pilots may attempt flights beyond their competence.
5. Under current regulations, Canadian Aviation Regulations (CARs) 703 and 704 operators are not required to provide training in crew resource management / pilot decision-making or threat- and error-management. A breakdown in crew resource management / pilot decision-making may result in an increased risk when pilots are faced with adverse weather conditions.
6. Descending below the area minimum altitude while in instrument meteorological conditions without a published approach procedure increases the risk of collision with terrain.
7. If onboard flight recorders are not available to an investigation, this unavailability may preclude the identification and communication of safety deficiencies to advance transportation safety.

The pilot's failure to maintain directional control of the airplane during the landing roll.

On Apr 22nd 2013 a letter of Kyrgyzstan's Transport Prosecutor to Kyrgyzstan's Parliament of April 2012 became known indicating that the airport had been approved to operate in Category I weather minima without being properly equipped and should never have been approved to operate in these conditions, as a result of the investigation the aerodrome has been limited to operate according to visual flight rules only. The aircraft was not properly equipped to conduct the flight lacking a GPWS as well as passenger oxygen, the crew was not qualified to conduct the flight and the oversight by the airline's dispatch and chief pilot was insufficient, the Transport Prosecutor mentioned that the responsibles to oversee flight operation could not answer even the most basic questions. Kyrgyzstan's Civil Aviation Authority failed to oversee the operation of the airline as well. While on approach to Osh the crew was informed about weather conditions permitting an approach, the data transmitted however were incorrect and the actual weather did not even permit an approach. Instead of being established on the approach 10.5km/5.6nm before touchdown the aircraft was established on the extended centerline only about 4.02km/2.17nm before touchdown, however was above the glidepath. A steep dive to reach the runway resulted in a touch down at a high rate of descent and vertical forces beyond the design limit of the aircraft (more than 2.5G), as result of the high impact forces the aircraft did not even bounce but just started to disintegrate, reaching 58 degrees of right roll 270 meters past the runway threshold, between 270 and 550 meters past the threshold the tail fin separated, the aircraft was completely upside down 600 meters past the threshold and came to a stop about 1000 meters past the threshold of the runway. The main door was jammed, the occupants escaped through other doors and the overwing exits. No serious injury occurred, 6 people needed hospital treatment with minor injuries.

The pilot’s failure to maintain adequate airspeed during a single-engine approach, which resulted in an aerodynamic stall. Contributing to the accident was the total loss of power in the left engine due to a failed No. 2 connecting rod bearing.

The pilot's failure to maintain minimum control airspeed after a loss of power to the right engine, which resulted in an uncontrollable roll into an inadvertent stall/spin. Contributing to the accident was the failure of the airplane's right engine for reasons that could not be determined because no preexisting mechanical anomalies were found, and the pilot's subsequent turn toward that inoperative engine while maintaining altitude.

Findings:
1. The aircraft was airworthy prior the accident. There was no evidence that the aircraft had malfunction during the flight.
2. The crew had valid license and medical certificate. There was no evidence of crew incapacitation.
3. In this flight Pilot in Command acted as Pilot Flying and Second In command acted as Pilot Monitoring.
4. The flight crew did not conduct approach crew briefing.
5. There was no checklist reading.
6. The PIC as Pilot Flying did not have the instrument approach procedure immediately available to review during approach.
7. During the approach, the PIC course indicator was set at 091 and the SIC was at 084.
8. The rate of descend recorded vary and up to 1920 ft per minute and below 500 ft AGL the rate of descend recorded up to 2040 ft per minute.
9. The approach did not meet the stabilize approach criteria as stated in the FCOM.
10. There were several GPWS warning of ‘sink rate’ and ‘pull up’ activated during approach.
11. The aircraft touched down at speed 156 Kt before bounced, instead of 138 Kt target landing speed.
12. The flap extended to 40 after the aircraft touch down.
13. The FDR recorded reduction in N1 during thrust reverser activation after landing.
14. The CRM was not well implemented.
Factors:
Unsuccessful to recognize the two critical elements, namely fixation and complacency affected pilot decision to land the aircraft while the approach was not meet the criteria of stabilized approach.

The AIB president found no clear and convincing evidence of the primary cause of the accident. He determined by a preponderance of evidence that the Landing Zone Condition, Cross-Monitoring Performance, Task/Mission-in-Progress Re-planning, Landing with an Excessive Tailwind, and Aircraft Engine Anomalies substantially contributed to the mishap, ultimately causing the mishap aircraft to veer off the prepared surface into rough terrain, resulting in the collapse of the nose landing gear and destruction of the aircraft.