Incident Summary
On 2 September 1999, at approximately 2325 local time (UTC+2), a Saab 2000 aircraft registered as HB-IZC, operated by Crossair AG on a scheduled flight from Basel, landed on runway 05 at Geneva Airport. During the landing roll, the crew observed an "L GEN FAULT" message on the Engine Indicating and Crew Alerting System (EICAS), followed by a strong smell of burnt oil. While braking, a "L ENG OIL PRESS LOW" warning appeared, and smoke entered the cockpit and the forward part of the cabin. The aircraft came to a stop on a taxiway, and the crew initiated the rapid disembarkation checklist. Passengers exited the cabin and were assisted by airport security staff.
Aircraft and Crew
The aircraft was a SAAB 2000, registration HB-IZC, owned by Stockholm Aircraft Ltd. and operated by Crossair AG. The crew consisted of two Swiss nationals: the commander, born in 1970, held an airline transport pilot license with 4635 total flight hours (1867 on type); the co-pilot, born in 1964, also held an airline transport pilot license with 3791 total flight hours (2552 on type). The aircraft was authorized for line operations, and weight and balance limits were respected.
Investigation Findings
The left engine nacelle was found to be leaking oil due to a rupture of the generator casing and its drive shaft. The following day, a replacement generator was installed but was damaged in the same manner during an engine ground run. Further analysis revealed that a pressure relief valve located between the air-oil and fuel-oil heat exchangers was defective, allowing excessively high oil pressure in the system. This caused the generator, as the weakest component, to fail, leading to oil flow into the air intake of the turbine, which generated contaminated air in the cabin conditioning system. Weather conditions were not a factor.
Cause
The incident was caused by smoke generation on the ground in the cockpit and part of the cabin, resulting from a defective pressure relief valve that damaged the left engine generator and produced an oil flow into the air intake.