What happened
On February 7, 2002, at 11:20 UTC, an Air France Airbus A320, registration F-GFKU, was performing a scheduled commercial flight from Lisbon (LPPT) to Paris-CDG. While taxiing toward the holding point for runway 03, the crew mistakenly lined up on taxiway U1, which runs parallel to the active runway.
After receiving takeoff clearance from the tower, the crew applied takeoff power while positioned on the taxiway. The aircraft accelerated to approximately 90 knots and traveled about 800 meters before the air traffic controller alerted the crew that they were departing on a taxiway. The crew immediately discontinued the takeoff, and the aircraft came to a stop without further incident or injuries to the 72 occupants.
The investigation
The GPIAAF investigation examined the sequence of communications and the environmental conditions at Lisbon Airport. The investigation noted that the aircraft was taxiing via taxiway M toward the runway 03 holding position. While the pilot was finishing a welcome announcement to the passengers, the co-pilot read back the takeoff clearance.
Investigators reviewed the airport's operational status, noting active construction works and the presence of various barriers near the taxiway area. The investigation also looked into the visibility and markings of the taxiway and runway, confirming that the physical markings met ICAO standards. Although the investigation was not formally concluded due to personnel changes, the incident was addressed and clarified among the involved parties.
Findings
Several contributing factors led to the mistaken takeoff on a taxiway:
- Pilot distraction: The commander's attention was divided by delivering a welcome announcement to passengers during the critical phase of receiving and confirming clearances.
- Visual confusion: The presence of numerous red barriers abandoned near the entrance of runway 03, which were visible from taxiway M2, created confusion. These barriers were not specifically highlighted in the ATIS or by ground control.
- Communication errors: The takeoff clearance was issued while the aircraft was still on taxiway M2 and again when it was aligned on taxiway U1, contributing to the error.
- Operational complexity: Ongoing construction works and discrepancies between the actual airfield state and the NOTAMs/charts contributed to the navigational confusion.
- ATC limitations: The controller's ability to verify the exact position of the aircraft was limited by the tower's viewing angle relative to the start of runway 03.