What happened
On November 21, 2005, a Saab 2000, registration CS-TLK, was operating a passenger flight from Valencia to Lisbon. During the approach to runway 03, the pilot encountered stationary cumulonimbus clouds near the Initial Approach Fix (CP NDB). To avoid the weather, the pilot decided to intercept the ILS earlier than planned, which resulted in the aircraft being high on the glide slope.
As the aircraft descended to intercept the localizer, the pilot increased the airspeed. Because the aircraft was not equipped with speedbrakes, the pilot attempted to use maximum flaps (35°) to increase drag; however, a flap limit switch prevented the full deployment until the aircraft slowed to the required speed. The aircraft remained above the glide slope throughout the final approach.
Upon landing, the aircraft experienced a strong tailwind component of approximately 27 knots. The nose gear made initial contact with the runway, but the aircraft continued to float. During the landing roll, the pilot applied brakes, but the aircraft failed to decelerate immediately. The aircraft drifted across the runway centerline due to wind effects before coming to a stop near taxiway exit U5. Following the stop, the crew discovered that all four main gear tires had burst.
The investigation
The GPIAAF investigation utilized data from the Quick Access Recorder (QAR), air traffic control transcripts, and pilot testimony to reconstruct the flight profile. The investigation focused on the sequence of the approach, the aerodynamic behavior of the aircraft, and the physical cause of the tire failures.
Investigators examined whether the tire bursts were caused by hydroplaning, heavy lateral forces from wind, or wheel locking. Analysis of the tire damage revealed localized faceting, which is consistent with the erosion caused by a locked wheel dragging against the runway surface rather than a loss of steering or hydroplaning.
Findings
- The pilot performed a deficient judgment by deciding to proceed with the landing rather than executing a missed approach (go-around) despite being high and fast on the approach.
- The co-pilot had correctly suggested a missed approach maneuver to rectify the unstable approach.
- The pilot underestimated the impact of the strong tailwind and the difficulty of decelerating on a wet runway.
- The primary cause of the tire bursts was the heavy faceting of the rubber caused by the main wheels being locked during contact with the runway surface.
- Adverse meteorological conditions, including heavy tailwind and rain, contributed to the incident.