What happened
On the evening of October 17, 2000, a Sabena flight, SN2337, arriving from Brussels, experienced a significant engine failure while parking at stand 25 of Helsinki-Vantaa Airport. As the Airbus A319, registration OO-SSH, was completing its parking maneuver, the left engine ingested aluminum maintenance ladders that had been left within the engine's intake suction zone. The ingestion caused severe damage to the engine, although the aircraft's 62 passengers and five crew members were unharmed. The incident occurred during the final stages of parking, following the disconnection of ground power.
The investigation
The investigation examined the sequence of events leading to the engine damage, the visibility conditions at the stand, and the ground handling procedures in place. Investigators reviewed the functionality of the Aircraft Parking and Information System (APIS) and the visibility of objects from the cockpit during twilight/darkness. The probe also looked into the management of ground support equipment and the adequacy of safety distances at the parking stand in relation to ICAO standards.
Findings
- The primary cause of the engine damage was a ramp supervisor forgetting to remove aluminum maintenance ladders from the engine's intake area after servicing a previous aircraft.
- The ramp supervisor failed to inspect the stand for cleanliness and obstructions prior to the arrival of the Airbus A319.
- The parking stand layout did not meet safety distance requirements; had the stand complied with ICAO Annex 14 standards regarding distances from structures, the ladders would likely have been outside the engine's suction zone.
- Visibility of the ladders from the cockpit was extremely difficult due to the grey color of the passenger bridge structures and the shadows cast by the terminal lighting during twilight.
- There was a lack of effective oversight regarding the tracking and management of maintenance equipment, as the ladders had been missing from their designated vehicle for some time prior to the accident.
- Ground handling instructions for ensuring stand cleanliness were insufficient.