Air Inter Flight 148 Crashes, Killing 87
Air Inter Flight 148 was a scheduled airline flight on 20 January 1992 that crashed in the Vosges Mountains, near Mont Sainte-Odile, while circling to land at Strasbourg Airport.
87 of the 96 onboard were killed.
Flight 148, commanded by Captain Christian Hecquet and First Officer Joël Cherubin, departed Satolas Airport (now known as Lyon-Saint Exupéry Airport) in Lyon, France. While being vectored for a VOR DME Approach to Runway 05 at Strasbourg, it crashed at 19:20:33 CET in the mountains at a height of 2,620 feet. The pilots had no warning of the imminent impact since the aircraft was not fitted with a ground proximity warning system (GPWS) by Air Inter.
Air Inter Flight ITF148, an Airbus A320, took off from Lyon (LYS) at 18:20 on a domestic service to Strasbourg-Entzheim Airport (SXB). Following an uneventful flight the crew prepared for a descent and approach to Strasbourg. At first the crew asked for an ILS approach to runway 26 followed by a visual circuit to land on runway 05. This was not possible because of departing traffic from runway 26. The Strasbourg controllers then gave flight 148 radar guidance to ANDLO at 11DME from the Strasbourg VORTAC. Altitude over ANDLO was 5000 feet. After ANDLO the VOR/DME approach profile calls for a 5.5% slope (3.3deg angle of descent) to the Strasbourg VORTAC. While trying to program the angle of descent, "-3.3", into the Flight Control Unit (FCU) the crew did not notice that it was in HDG/V/S (heading/vertical speed) mode. In vertical speed mode "-3.3" means a descent rate of 3300 feet/min. In TRK/FPA (track/flight path angle) mode this would have meant a (correct) -3.3deg descent angle. A -3.3deg descent angle corresponds with an 800 feet/min rate of descent. The Vosges mountains near Strasbourg were in clouds above 2000 feet, with tops of the layer reaching about 6400 feet when flight 148 started descending from ANDLO. At about 3nm from ANDLO the aircraft struck trees and impacted a 2710 feet high ridge at the 2620 feet level near Mt. Saint-Odile. Because the aircraft was not GPWS-equipped, the crew were not warned.
On January 20, 1992 this Airbus crashed on approach to Strasbourg due to a programming error entered by the flight crew into the navigational computer. 87 people onboard the plane died, and as a result Airbus overhauled its computer input readouts to accommodate more input safety precautions.