Air India Flight 101 - Investigation

Investigation

At the time, aircrew fixed the position of their aircraft as being above Mont Blanc by taking a cross-bearing from one VHF omnidirectional range (VOR) as they flew along a track from another VOR. However, the accident aircraft departed Beirut with one of its VOR receivers unserviceable.

The investigation concluded:

a) The pilot-in-command, who knew on leaving Beirut that one of the VORs was unserviceable, miscalculated his position in relation to Mont Blanc and reported his own estimate of this position to the controller; the radar controller noted the error, determined the position of the aircraft correctly and passed a communication to the aircraft which, he believed, would enable it to correct its position. b) For want of a sufficiently precise phraseology, the correction was mis-understood by the pilot who, under the mistaken impression that he had passed the ridge leading to the summit and was still at a flight level which afforded sufficient safety clearance over the top of Mont Blanc, continued his descent.