What happened
On 12 January 2011, a Socata TBM 850, registration N850TV, was conducting a private flight from Italy to Birmingham Airport. During the arrival phase, the pilot experienced a loss of two-way communication with the tower. This was caused by the pilot accidentally selecting the wrong radio frequency, which he misidentified as a total radio failure.
While the pilot was attempting to re-establish contact, the tower controller was managing a complex sequence involving a departing DHC-8-402. To maintain separation, the controller cleared the Q400 to line up and wait on Runway 15. Because the pilot of N850TV believed his radios had failed, he did not respond to subsequent attempts by the tower to establish contact. Consequently, the pilot continued the approach and landed the aircraft without receiving clearance, unaware that another aircraft was occupying the runway extension.
The investigation
The AAIB examined flight data from the Socata TBM 850, surface movement radar recordings, and air traffic control communications. The investigation established that the pilot had tuned 118.030 MHz instead of the required 118.300 MHz. The investigation also reviewed the tower controller's workload and the availability of visual signaling tools. It was noted that the signal lamp, which could have been used to provide visual instructions to the non-communicating aircraft, had been removed from the tower due to previous studies regarding its limited effectiveness.
Findings
- The pilot's frequency mis-selection led to a perceived loss of communications.
- High workload during the approach, compounded by the frequency change and the need to manage the approach profile, contributed to the pilot's inability to diagnose the error.
- A plan continuation bias likely influenced the pilot's decision to proceed with the landing despite the lack of response from the tower.
- The tower controller's plan for traffic separation had very little margin for error, as the arrival of the N850TV coincided with the departure preparations of the Q400.
- The pilot's visual search failed to detect the Q400 on the runway, likely due to the high descent rate and the bright lighting of the runway starter extension.