45 fatalities

1979-08-04: Hindustan Aeronautics HAL-748 (VT-DXJ) — Indian Airlines — Mumbai, India

Mumbai, IndiaLanding (descent or approach)

On August 4, 1979, a Hindustan Aeronautics HAL-748 (registration VT-DXJ) operated by Indian Airlines was involved in an aviation accident near Mumbai, India during landing or approach. 45 people were killed. Investigators recorded the probable cause as: The accident was the consequence of the combination of the following factors: - Momentary/intermittent loss of electrical contact in G/S system of aircraft which gave the pilot an erroneous impression of the interception of the glide slope, - Failure of the… This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781224962Data APIEditorial standards

An aircraft struck Mt Kisoli while approaching Bombay Airport at night. All 45 occupants were killed. SAR was hampered by poor visibility and heavy rain. The official investigation cited intermittent loss of glide slope electrical contact, pilot error, and radar controller failures.

Accident

While approaching Bombay Airport from the southeast during nighttime, the aircraft encountered technical problems and struck the slope of Mt Kisoli, located 30 km southeast of Bombay Airport. Search and rescue operations were hampered by a lack of visibility and heavy rainfall. The wreckage was located a few hours later. All 45 occupants were killed.

Probable Cause

The official investigation determined the accident resulted from a combination of factors: a momentary or intermittent loss of electrical contact in the aircraft's glide slope (G/S) system, which gave the pilot an erroneous impression of glide slope interception; the pilot's failure to adhere to DOC 4444 by not using the glidepath facility only after the Outer Marker and by descending below 2,910 feet without first cross-checking over the Outer Marker; and the radar controller's failure to comply with DOC 4444 by not providing position information to the aircraft, using incorrect or non-standard phraseology, and failing to inform the aircraft about the loss of radar contact.