Kyrgyzstan

The cause of the Boeing 747-412F TC-MCL aircraft accident was the missing control of the crew over the aircraft position in relation to the glideslope during the automatic approach, conducted at night in the weather conditions, suitable for ICAO CAT II landing, and as a result, the measures to perform a go-around, not taken in due time with the aircraft, having a significant deviation from the established approach chart, which led to the controlled flight impact with terrain (CFIT) at the distance of ≈930 m beyond the end of the active RWY.
The contributing factors were, most probably, the following:
- the insufficient pre-flight briefing of the flight crew members for the flight to Manas aerodrome (Bishkek), regarding the approach charts, as well as the non-optimal decisions taken by the crew when choosing the aircraft descent parameters, which led to the arrival at the established approach chart reference point at a considerably higher flight altitude;
- the lack of the crew's effective measures to decrease the aircraft vertical position and its arrival at the established approach chart reference point while the crew members were aware of the actual aircraft position being higher than required by the established chart;
- the lack of the requirements in the Tower controllers' job instructions to monitor for considerable aircraft position deviations from the established charts while the pertinent technical equipment for such monitoring was available;
- the excessive psycho-emotional stress of the crew members caused by the complicated approach conditions (night time, CAT II landing, long-lasting working hours) and their failure to eliminate the flight altitude deviations during a long time period. Additionally, the stress level could have been increased due to the crew's (especially the PIC's) highly emotional discussion of the ATC controllers' instructions and actions. Moreover, the ATC controllers' instructions and actions were in compliance with the established operational procedures and charts;
- the lack of the crew members' monitoring for crossing the established navigational reference points (the glideslope capture point, the LOM and LIM reporting points);
- the crew's failure to conduct the standard operational procedure which calls for altitude verification at the FAF/FAP, which is stated in the FCOM and the airline's OM. On the other hand, the Jeppesen Route Manual, used by the crew, contains no FAF/FAP in the RWY 26 approach chart;
- the onboard systems' "capture" of the false glideslope beam with the angle of ≈9°;
- the design features of the Boeing 747-400 aircraft type regarding the continuation of the aircraft approach descent in the automatic mode with the constant descent angle of 3° (the inertial path) with the maintained green indication of the armed automatic landing mode (regardless of the actual aircraft position in relation to the RWY) while the aircraft systems detected that the glideslope signal was missing (after the glideslope signal "capture"). With that, the crew received the designed annunciation, including the aural and visual caution alerts;
- the absence of the red warning alert for the flight crew in case of a "false" glideslope capture and the transition to the inertial mode trajectory, which would require immediate control actions from the part of the crew;
- the lack of monitoring from the part of the crew over the aircraft position in regard to the approach chart, including the monitoring by means of the Navigation Display (ND), engaged in the MAP mode;
- the crew's failure to conduct the Airline's Standard Operational Procedures (SOPs), regarding the performance of the go-around procedure in case the "AUTOPILOT" (the AP switching to the inertial mode) and "GLIDESLOPE" (the EGPWS annunciation of the significant glideslope deviation) alerts during the automatic CAT II landing at true heights below 1000 ft (with no visual reference established with either the runway environment or with the lighting system);
- the delayed actions for initiating the go-around procedure with no visual reference established with the runway environment at the decision height (DH). In fact, the actions were initiated at the true height of 58 ft with the established minimum of 99 ft.

It was determined that the accident occurred in poor weather conditions with an horizontal visibility reduced to 50 meters and a vertical visibility limited to 130 feet. It was reported that the accident was caused by the combination of the following factors:
- the crew decided to leave Bishkek Airport for Osh without taking into consideration the weather forecast and the possibility of deteriorating weather,
- the competences of the captain for a missed approach procedure in poor weather conditions were limited to a simulator training despite the fact that he was certified for Cat IIIa approaches,
- failure of the crew to comply with the standard operating procedures for a missed approach,
- wrong actions on part of the pilot in command while crossing the runway threshold at a height of 125 feet and about five seconds after the initiation of the TOGA procedure, disrupting the go around trajectory and causing the aircraft to continue the descent,
- lack of reaction of the copilot who did not try to correct the wrong actions of the pilot in command,
- lack of concentration on part of the crew who failed to control the approach speed and failed to recognize the pitch angle that was increasing,
- it is possible that the crew suffered somatogravic illusions caused by fatigue due to a duty time period above 13 hours,
- a non proactive reaction of the crew when the GPWS alarm sounded.

In violation of Section 5.1.15 of the Guidelines for Aviation Chemical Works (ACW), the Aircrew Commander (AC) decided to combine the production flight with followed inspection of the new site, taking a representative of the Customer on board. In violation of Section 5, PPLS, the passenger was seating in the co-pilot seat and this is prohibited. Before making a decision to operate a flight, the Aircrew Commander received an indicative weather forecast from the hydro meteorology experts of Osh International Airport. The revised weather forecast was not drawn up and the crew did not receive it because the flight control officer did not send an actual weather data provided by the crew after take-off, in accordance with the requirements of paragraph 8.7.7, APKR-3 . The technology of air traffic controllers’ work at Osh International Airport does not include responsibility for the transfer of information about the actual weather obtained from the crews to base aerodrome meteorological office responsible for forecasting weather and it does not specifically define the actions of air traffic services in obtaining information about an aviation accident. No changes were made in the temperature regime when performing aviation chemical works in accordance with the Guidelines for the Implementation of ACW technology in Agriculture and Forestry” designed by the Civil Aviation Ministry, USSR, and issued on December 30, 1980, Number 668/Y (these instructions were entered into operation by the order of the Director of the Civil Aviation Department under the Kyrgyz Ministry of Transport and Communications on March 20, 2009, number 188/p in the “List of Legislative Acts Regulating the Civil Aviation Activities of the Kyrgyz Republic”). Portable emergency radio beacon, PARM -406, did not function at the time of the accident. The Statute of Aeronautical Search and Rescue Service of the Kyrgyz Republic has no changes related to its reorganization in 2007.

The board president found, by clear and convincing evidence, the cause of the mishap was the MA’s tail section separating due to structural overstress as a result of the MC’s failure to turn off either the SYD (Series Yaw Damper) or the rudder power and oscillating dutch roll-induced acceleration forces translating through the MP’s feet as the MP used rudder during the unrecognized dutch roll condition. Additionally, the board president found, by a preponderance of evidence, that the dutch roll was instigated by the MA’s malfunctioning Flight Control Augmentation System that caused directional instability or rudder hunting which substantially contributed to this mishap. Other substantially contributing factors include insufficient organizational training programs, crew composition, and cumbersome procedural guidance.

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.

Engine failure 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 cause of the Itek Air B737-200 ЕХ-009 accident during the air-turn back due to the cabin not pressurizing (probably caused by the jamming of the left forward door seal) was that the crew allowed the aircraft to descend at night to a lower than the minimum descent altitude for visual approach which resulted in the crash with damage to the aircraft followed by the fire and fatalities. The combination of the following factors contributed to the accident:
- Deviations from the Boeing 737-200 SOP and PF/PM task sharing principles;
- Non-adherence to visual approach rules, as the crew did not keep visual contact with the runway and/or ground references and did not follow the prescribed procedures after they lost visual contact;
- Loss of altitude control during the missed approach (which was performed because the PIC incorrectly evaluated the aircraft position in comparison with the required descent flight path when he decided to perform visual straight-in approach);
- Non-adherence to the prescribed procedures after the TAWS warning was triggered.