What happened
On 12 October 2024, at Gran Canaria Airport (GCLP), a loss of separation occurred between two Boeing 737-800 aircraft. The first aircraft, 9H-QBL (call sign RYR5822), was on final approach to runway 03R. Simultaneously, the second aircraft, EI-IFS (call sign RYR2296), was cleared to line up and take off on the same runway.
As the aircraft on final approach reached an altitude of approximately 350 feet, the departing aircraft began its takeoff roll. To avoid a collision, the crew of 9H-QBL decided to abort the approach and initiate a right turn. During the maneuver, the departing aircraft crossed ahead of the arriving aircraft, resulting in a minimum horizontal separation of 0.9 NM and a vertical separation of 300 ft.
During the event, the crews of both aircraft, along with a third aircraft (VLG15NL), attempted to contact the control tower but received no response. The crews eventually regained separation by contacting their respective approach and departure sectors directly.
The investigation
The investigation established that the air traffic controller authorized the takeoff of EI-IFS while there was insufficient space between it and the arriving 9H-QBL.
Furthermore, the investigation found that the tower's ability to transmit instructions to aircraft was compromised. The controllers were using telephones rather than headsets, and the connection pins of the communications device were incorrectly connected. This prevented any outgoing messages from the tower from reaching the aircraft frequencies. The investigation noted that the instructor controller was unaware of this transmission failure, and the supervisor failed to detect the issue due to other operational tasks.
Findings
- The primary cause of the loss of separation was authorizing a takeoff when an aircraft was already on final approach with insufficient spacing.
- A significant contributing factor was a communications failure caused by incorrectly connected pins in the tower's communication equipment, which prevented the transmission of instructions to the aircraft.
- The crews of the involved aircraft did not utilize the emergency frequency (121.5 MHz) to establish contact, though they successfully managed the conflict by switching to approach and departure frequencies.