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 Porto Airport in 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, specifically focusing on runway inspection protocols and communication between airport operations and air traffic control. The investigation reviewed the reliability of radio equipment in Follow-Me vehicles and the effectiveness of the TETRA communication system. The investigators also analyzed the standardization of runway inspections and the role of the airport's safety committee.
Findings
- The radio scanners installed in the Follow-Me vehicles were unreliable and difficult to operate, and airport operations officers had not received training on this specific equipment.
- The use of the TETRA system created a communication gap, as it did not allow all stakeholders sharing the runway space to monitor movements.
- There was a lack of standardized procedures (SOPs) for runway inspections, which led to an uncoordinated process and a prolonged period of radio silence during inspections.
- The presence of the Follow-Me vehicle on the runway during the aircraft's takeoff roll was the critical factor in this serious incident.
Safety action
- The investigation issued a recommendation for ANA Aeroportos de Portugal to install and certify reliable, easy-to-use radio equipment (transmitter/receiver) in Follow-Me vehicles to ensure effective monitoring of runway operations.
- A recommendation was made to standardize runway inspection procedures and provide guidance material for Follow-Me operators to improve air traffic controller situational awareness.