Taxiing

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.

Failure of the right main gear during taxi due to the presence of corrosion in the trunnion.

The Captain's decision to shutdown the left engine during taxi with no hydraulic pressure on the right side hydraulic system to effectively operate the brakes, steering, or thrust reversers. A factor was the fatigue fracture of the rudder shutoff valve which resulted in the loss of right side hydraulic pressure.

The accident was caused by electrical arcing at the power cable to a submersible fuel pump. This arcing occurred above the kerosene liquid inside the tank full of fuel vapors. The cable type used was chosen at the time of the design of the aircraft. Atmospheric conditions on the apron of Fort de France have raised the temperature of the reservoir beyond the flash point kerosene. The vapors contained in this tank were explosive, and the arc was enough to initiate the blast. As such, atmospheric conditions are a certain cause of environmental origin of the accident. The appearance of the arc is, in turn, has only technical causes:
- The quality of cable used and age are in fact responsible for the creation of the electric arc.
- The formation of the insulating sheath of this type of cable is not likely to ensure an absolute seal. This quality is also not claimed by its manufacturer.
Indeed, the analysis carried out show a porosity of electrical cable, even nine, therefore that it is soaked in kerosene. The presence of kerosene increases the phenomenon of porosity of old cables. Degradation characteristics of dielectric strength of the cable insulation explains the appearance of the arc. The accident occurred while the cable was over 19 years old. The fuel pumps wiring has never been a problem. But there has not been a cable that had reached the age of 19 years. The aging of the cable could still degrade the seal. Finally, maintaining this type of cable on the first C160 series until this accident was part of a complex process in which traceability has not been formally established. Doubts indeed appeared in 1969 on the quality of these cables, doubts that can be considered today as precursors. Measures had been adopted precisely to overcome these deficiencies. In this regard, the replacement of the fuel pump wiring of the second series C 160 of these cables with a newer type and considered more efficient is particularly significant. Its extension to the first series aircraft might have seemed relevant, and would probably have prevented the accident. The reasons which led to the maintenance of such cables on the C 160 series first held in both the human factor (underestimation of risk, lack of global view on the issue) and organizational factors, which can be seen as a lack of traceability of technical and logistic actions, a lack of consistency of the measures adopted, and probable deficiencies in the information flow.

The failure of the pilot of the taxiing aircraft to maintain clearance and adequate visual lookout for the stopped aircraft.

Failure of the swinging lever of the left main gear due to the presence of fatigue cracks.

Maintenance personnel failure to maintain aircraft control as a result of excessive throttle input.

No investigations were conducted by the NTSB on this event.