What happened
On February 27, 2009, at approximately 20:10 UTC, a BAe 146/200 cargo flight, registration OO-TAU, was operating from Lisbon Airport (LPPT) to Toulouse Blagnac (LFCTX). The aircraft was positioned on runway 03, having been cleared to line up following the departure of a Boeing 767. Although the crew had confirmed they were ready for immediate departure, the aircraft did not depart as planned.
Following the departure of the preceding Boeing 767 at 20:07:25, the BAe 146/200 was cleared for takeoff at 20:08:55, while the previous traffic was at an altitude of 1,300 feet. At 20:09:25, air traffic control instructed an arriving aircraft (TP-843) on final approach to continue its approach, noting that the runway was occupied by the departing cargo flight. The crew of OO-TAU then responded that they required an additional minute before takeoff due to wake turbulence from the preceding heavy aircraft.
Air traffic control instructed the crew to vacate the runway via taxiway "N2"; however, the aircraft was unable to clear the runway in a timely manner, resulting in a loss of separation with the arriving TP-843.
The investigation
The GPIAAF examined air traffic communications to reconstruct the sequence of events. The investigation focused on the timing of the departures and the adherence to separation standards. The investigation noted that the crew had previously confirmed readiness for immediate takeoff and had not requested an extended separation interval.
Findings
- The crew of the BAe 146/200 requested an additional minute for takeoff due to wake turbulence concerns, despite having previously declared themselves ready for immediate departure.
- The separation between the departure of the heavy aircraft and the BAe 146/200 was approximately 90 seconds at the time of takeoff clearance.
- The total time elapsed between the departure of the first aircraft and the delayed departure of the second aircraft was approximately two minutes.
- According to ICAO Doc 4444 standards, a two-minute separation is required between a medium aircraft and a heavy aircraft using the same runway; however, the delay requested by the crew led to the runway remaining occupied, causing the loss of separation with the arriving aircraft.