Air Inter Flight 148

Air Inter
Industry	Airline
Founded	1954
Defunct	1997 (merged into Air France)
Headquarters	France

Air Inter Flight 148 (ICAO callsign ITF 148 DA, IATA designation Air Inter Flight 5148) was a regular passenger route operating between Lyon-Saint-Exupéry Airport and Strasbourg Airport in France. On 20 January 1992, the Airbus A320 assigned to this flight collided with the Vosges Mountains near Mont Sainte-Odile during a non-precision approach to Strasbourg. The crash resulted in 87 deaths among the 96 people on board, with nine survivors who sustained injuries.

Accident

The flight was under the command of Captain Christian Hecquet, aged 42, who had accumulated 8,800 flight hours, including 162 on the A320 model. The First Officer, Joël Cherubin, aged 37, had logged 3,600 hours of flight time, with 61 hours on the A320. The aircraft departed from Lyon-Satolas (currently Lyon-Saint-Exupéry Airport) at 17:20 UTC. Although both pilots had relatively limited experience flying the A320—approximately 300 hours combined—they were familiar with operations at Strasbourg Airport.

While approaching Strasbourg, the crew requested an Instrument Landing System (ILS) approach for Runway 23 followed by a visual approach to Runway 05, a routine procedure at Strasbourg since Runway 05 lacked ILS due to terrain restrictions. Air Traffic Control (ATC) rejected this request because of conflicting traffic and instead offered guidance for the VOR/DME approach to Runway 05, which the pilots accepted. The aircraft was cleared to descend to an altitude of 5,000 feet and vectored toward the ANDLO waypoint located 11 nautical miles from Strasbourg VOR. At 18:19 UTC, after passing ANDLO, ATC authorized the final approach; the pilots turned left to a heading of 050 degrees and continued descending according to the approach charts.

At 18:20:33 UTC, Flight 148 impacted the slopes of Mont Sainte-Odile at an altitude of approximately 2,620 feet, situated about 10.5 nautical miles from the airport. Search and rescue efforts commenced at 18:40 involving three helicopters, twenty-four motorcycles, and roughly 950 personnel drawn from Police Nationale, National Gendarmerie, Sécurité Civile, as well as amateur radio operators. Despite extensive deployment of resources, coordination difficulties among agencies delayed discovery of the crash site. It was not located until 22:35 UTC—more than four hours later—when survivor Nicolas Skourias led journalists to the wreckage. The first rescuers reached the site at 22:49 following guidance from Skourias and a journalist.

Cause

The Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) concluded that Flight 148 crashed because the flight crew left the autopilot engaged in Vertical Speed Mode, which controls descent rate in feet per minute rather than Flight Path Angle Mode that manages descent by angle relative to the horizon. The pilots input "33" intending to set a descent path angle of 3.3°. However, since only the first two digits of vertical speed in hundreds of feet per minute were displayed, "33" was interpreted as a descent rate of 3,300 feet per minute. This caused an unintended rapid descent at that rate until impact.

No alert was triggered for the crew because there was no ground proximity warning system (GPWS) installed on the aircraft; at that time GPWS was not mandatory for A320s. It is believed that Air Inter chose not to equip their fleet with GPWS in order to avoid nuisance alarms related to their operational practice of flying at high speeds—up to —to compete effectively against France’s TGV high-speed trains.

Aircraft

The aircraft involved was an Airbus A320-111 (registration F-GGED, serial number 015), manufactured in 1988. At the time of the incident, it had accumulated 6,316 flight hours and completed 7,194 cycles.

Aftermath

The investigation led to 35 proposed modifications. Airbus revamped the autopilot interface to present vertical speed as a four-digit figure, removing ambiguity with the Flight Path Angle mode. The flight data recorder was enhanced to endure elevated temperatures for extended durations. The final report emphasized the need for improved pilot training specific to the A320 and required the installation of Ground Proximity Warning Systems (GPWS) on all A320 aircraft. Prior to the conclusion of the inquiry, Air Inter had already equipped its fleet with GPWS.

Notable deaths

Jean-Pierre Lecocq, Belgian molecular biologist and entrepreneur.

Dramatization

This tragedy was depicted in the ninth season of the Cineflix series Mayday under the episode titled "The Final Blow" (also known as "Crashed and Missing" or "Doomed to Fail," S09E07). Additionally, it is featured in season 2, episode 5 of Why Planes Crash, named "Sudden Impact."

External links