Introduction
On 30 November 2011, at 07:26 local time (05:26 UTC), an Airbus A320-232, registration HA-LPV, operated by Wizz Air, experienced an incident during takeoff from Runway 07 at Aurel Vlaicu Bucharest-Băneasa International Airport, Romania. The aircraft was scheduled to fly to Bergamo-Orio al Serio Airport, Italy.
History of the Incident
During the takeoff roll, as the aircraft became airborne, the exterior fan cowl of the engine No.1 nacelle detached. The aircraft behaved normally, and the crew was informed of the occurrence by passengers. The captain assessed the situation and decided to return to the departure airport. The return flight and landing were normal, and passengers disembarked using standard procedures. The crew did not declare an emergency. Air traffic control informed airport staff, and after inspecting the runway, components from the aircraft were found. A post-flight visual inspection revealed the absence of the exterior cowl, which had broken at the fastening joints on the nacelle.
Damage to the Aircraft
The incident caused multiple damages, including breakage of the exterior cowl of engine No.1 nacelle, deformation of the left wing flap, breakage of the leg and de-icing system valve pin, a deep cut in the exterior tire of the main left landing gear, strong contortion of the pillar skin and console structure of engine No.1, deformation of engine No.1 edge pillar, a 0.3 mm bounce on the left wing underside, bending of left wing slat No.2, bending of the guideway of the interior left flap, breakage of the rubber strip of the engine No.1 nacelle interior cowl, breakage of the cross beam and carcass of the engine No.1 equipment gear, and breakage of the engine No.1 air intake cover.
Maintenance Background
The Wizz Air operator had contracted certain routine maintenance tasks (Standard Work Package) to Lufthansa Technik. The aircraft entered the Lufthansa Technik hangar on the evening of 29 November 2011 for scheduled work. After completion, the aircraft was towed to the airport platform and sealed according to the maintenance organization's work sheet.
Additional Information
The manufacturer noted that similar incidents involving detachment of engine nacelle cowls had occurred on Airbus A320 aircraft, with 80% of such events happening during takeoff. Other Airbus family aircraft with similar cowl design also experienced incidents, though in smaller numbers. The main landing gear tires exhibited cuts, possibly caused by debris from the detached cowl. Each engine nacelle cowl weighed approximately 40 kg. During the takeoff roll and after the occurrence, all onboard parameters indicated normal operation.
Conclusions
The investigation identified that the exterior nacelle cowl was improperly closed and secured by maintenance personnel, leading to its detachment during takeoff. No injuries were reported. The flight crew returned the aircraft safely.