What happened
On April 27, 2021, at 20:48 UTC, a Boeing 737-476 (registration OE-IAJ), operated by ASL Airlines Belgium, was performing a takeoff from the runway at Porto Airport, Portugal. During the takeoff roll, a Follow-Me vehicle was present on the runway.
The investigation
The GPIAAF investigation examined the operational procedures at Porto Airport, focusing on the coordination between air traffic controllers and airport operations officers. The investigation reviewed the use of radio equipment in Follow-Me vehicles, the reliability of the TETRA communication system, and the procedures for runway inspections. The investigators also looked into the standardization of runway inspection methods and the effectiveness of the radio scanners used by airport personnel to monitor tower communications.
Findings
- The radio scanners installed in the Follow-Me vehicles were unreliable and difficult to operate.
- Airport operations officers had not received training on the use of these specific radio-scanning devices.
- The use of the TETRA system created communication gaps, as it did not allow all personnel and vehicle operators in the maneuvering area to monitor the same frequency.
- There was a lack of standardized operating procedures (SOPs) for runway inspections, which led to a prolonged period of radio silence during the inspection process.
- The presence of the Follow-Me vehicle on the runway during the aircraft's takeoff roll was the primary safety concern identified.