Bishkek City

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.

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.

The collision between the TU-154 and KC-135R aircraft was clearly an accident and not the result of any intentional conduct. The Accident Investigation Board, convened by AMC, determined that the accident was caused by the Kyrgyzaeronavigation air traffic controller who cleared a civilian airliner for takeoff without verifying that the KC-135R was clear of the runway. In addition to the air traffic controller, the AIB found evidence of several contributing factors involving the KC-135R aircrew, conflicting published airport notices, and a tower liaison employed by the U.S. Government to facilitate communication between the tower and U.S. aircrews. Although the AIB found the air traffic controller primarily at fault, the U.S. KC-135R crew and tower liaison shared responsibility for ensuring the KC-135R cleared the runway to a safe location following landing. The accident might have been avoided had any of them exercised better awareness of their situation.
In conclusion, the AIB determined the principal cause of the mishap was the Kyrgyzaeronavigation controller clearing the TU-154 for takeoff without verifying that KC-135R was clear of the runway, there was evidence the following factors also contributed to the mishap:
- The Kyrgyz air traffic controller's instruction to vacate at taxiway Golf after dark conflicted with a published Notice to Airmen (NOTAM) that limited that taxiway's use to daylight hours. The contractor safety liaison (LNO) employed by the U.S. Air Force to facilitate communication between its aircrews and Kyrgyz controllers did not clarify the apparent discrepancy.
- After questioning the Kyrgyz controller's instruction to vacate the runway at taxiway Golf, the LNO instructed the KC-135R crew to hold short of Alpha. The mishap KC-135R crew misperceived the LNO's instructions and responded "holding short of Golf." The LNO failed to catch the read-back error.
- The Kyrgyz controller failed to maintain awareness of the KC-135R's location.
- The LNO failed to maintain situational awareness and intervene when the controller's actions endangered the KC-135R and aircrew.
The KC-135R is assigned to the 92nd Air Refueling Wing, Fairchild Air Force Base, Wash. While deployed at Manas AB, the KC-135R and its aircrew were assigned to U.S. Central Command's 376th Air Expeditionary Wing, flying missions supporting coalition aircraft over Afghanistan.

Wrong approach configuration on part of the flying crew, which caused the airplane to land too far down the runway. The following contributing factors were identified:
- Poor crew coordination,
- The pilot-in-command who was also the General Manager of the company, did not had sufficient training and qualifications to act in such position,
- Poor crew resources management,
- Poor flight and approach planning.

Failure of the main hydraulic system due to the loss of the cap of the hydraulic tank caused by the destruction of the nut due to fatigue caused by structural and manufacturing faults.

The accident was the consequence of several errors on part of the flying crew which led the aircraft in a configuration that became uncontrollable. The instructor allowed a pilot under training to seat in the front left seat while his experience and capabilities were insufficient for such flight configuration. The crew decided to deploy the flaps at 30° with both right engines not running, which caused the airplane's speed to drop to a critical value of 220 km/h. The decision of the crew to restart both right engines was too late.

Double engine failure caused by a loss of fuel pressure. Possible fuel exhaustion.