What happened
On the morning of December 2, 1997, heavy snowfall at Orly Airport resulted in a significant accumulation of snow, reaching approximately 6 to 7 cm. Due to delayed snow removal operations, the airport was effectively closed from 05:00 until 08:35 UTC.
At 09:43 UTC, an Air Liberté MD83, registration F-GHEI, departed on flight TA 769. During the initial climb, at an altitude of approximately 131 feet, the crew heard an explosion and observed the fire warning light for the right engine illuminate. The crew immediately executed emergency procedures, activating both fire extinguishers and shutting down the right engine. The aircraft performed an emergency landing at 09:51 UTC without further incident.
Approximately forty minutes later, at 10:24 UTC, a second Air Liberté MD83, registration F-GFZB, began its takeoff roll on runway 08. As the aircraft reached a speed of approximately 65 knots, the left engine experienced a compressor stall (surge). The crew promptly aborted the takeoff and returned to the parking stand.
The investigation
The investigation focused on the impact of the recent weather conditions and the effectiveness of the aircraft de-icing and runway clearing processes. Investigators examined the engines of both aircraft to determine the extent of the damage and the role of snow ingestion.
Findings
- The investigation established that the right engine of F-GHEI had absorbed a massive amount of melting snow, which damaged the air intake and caused the failure of eleven fan blades, while also damaging the leading edges of the remaining blades. The left engine of the same aircraft also sustained damage to two fan blades.
- The left engine of F-GFZB had absorbed melting snow, which resulted in damage to fifteen fan blades, leading to the engine surge during the takeoff roll.
- The primary cause of the engine damage in both instances was the ingestion of melting snow into the engine intakes.
- The delay in runway and taxiway clearing, combined with the fact that the aircraft had been pushed back through areas that had not yet been fully cleared of snow, contributed to the accumulation of moisture in the engine inlets.