C5/2010L Serious incident at Helsinki-Vantaa Airport on 12 June 2010

On 12 June 2010 an AVRO 146-RJ85 airliner, registered OH-SAR and operated by Blue1 Ltd on flight number BLF639, suffered severe engine damage during take-off run at Helsinki-Vantaa Airport runway 22R. The pilots aborted take-off at 03:47 UTC. As a result of the engine damage, a significant amount of engine pieces was left on the runway. A serious incident occurred as two transport aircraft were cleared for take-off from the same runway before the engine pieces were removed. There were 93 passengers and 4 crew members on board of OH-SAR. No one was injured in the incident.

After OH-SAR had vacated the runway, a runway inspection was carried out by one airport maintenance worker at the air traffic control’s request. The runway was reported to be free of obstacles, and the controller cleared two transport aircraft for take-off from the same runway. After that, the pilot-in-command of OH-SAR contacted the air traffic control by telephone and told about the severe nature of the engine damage. For this reason, the controller requested a new runway inspection, specifying the area to be inspected and what should be looked for. The inspection was conducted by two airport maintenance staff members and two cars. This time, engine pieces were found on the runway. The runway was swept before the next aircraft took off. The crews of the two transport aircraft which took off from the runway after the first inspection were informed of the situation through Tallinn ATC.

The instructions of Blue1 Ltd concerning pilot actions in the event of aborted take-off were found to be adequate. It was concluded that the engine damage resulted from a fatigue fracture in the root of a second-stage turbine rotor blade, which was probably caused by overheat in the engine although other causes could not be excluded. The fracture could not be predicted on the basis of current engine condition monitoring procedures, which showed no difference between the damaged engine and the other engines. Engine maintenance actions had been signed as having been performed properly and on time, without exceeding any service life limitations.

A serious incident developed because two transport aircraft were cleared for take-off while there were engine pieces on the runway, which could have damaged the aircraft during take-off run. The engine pieces remained on the runway, since they were not found in the first runway inspection carried out after the aborted take-off. The first runway inspection failed partly because any detailed assessment about the nature and location of the incident was not given in conjunction with the inspection request, and the airport maintenance unit therefore did not see any specific reason to inspect the runway more thoroughly than usual. The ATC actions when asking for runway inspection and providing related information to the airport maintenance unit were in accordance with the instructions and established practices at the aerodrome.

Based on the investigation, the investigation commission recommends the Finnish airport operator Finavia Corporation to make the instructions for runway inspections more specific, so that the inspecting staff would have all available necessary information about the situation at their disposal during the inspection. Secondly, Finavia Corporation is recommended to find out whether any technology suitable for the local conditions is available for detecting foreign objects on the runway and, based on studies, decide on the necessity of obtaining such equipment. The Aviation Sector of the Finnish Transport Safety Agency (Trafi) is recommended to examine the instructions provided by air carriers operating in Finland to their technical staff in cases where aircraft parts may remain on the runway and the ATC should be informed about that without delay. Based on the investigation, the commission also suggests that Finavia Corporation increase regular and continuous co-operation between ATC and airport maintenance unit operations staff at all of its airports.

C5/2010L Report (pdf, 3.28 Mt)