What happened
On 21 July 2017, an AIRBUS A321, registration G-OZBH, was performing an ILS approach to runway 01 at Menorca Airport (LEMH). Minutes prior, an AQUILA A-210, registration D-EPIG, had departed from the nearby San Luis aerodrome (LESL) for a local VFR flight.
Air traffic services had cleared the AQUILA A-210 to cross from east to west behind the flight path of the AIRBUS A321. Although the pilot of the AQUILA A-210 requested a left turn—which was authorized—the aircraft did not execute the maneuver as planned. Instead, the light aircraft crossed the approach path approximately 400 ft below the AIRBUS A32 and 1, resulting in a loss of horizontal separation.
As a result of the proximity, the crew of the AIRBUS A321 received a TCAS RA (Resolution Advisory) command to "LEVEL OFF." The crew followed standard procedures, leveling the aircraft and executing a missed approach. The AIRBUS A321 eventually completed a second approach and landed safely. There were no injuries and no damage to either aircraft.
The investigation
The CIAIAC investigation examined the communications between the air traffic controller and both pilots, as well as the flight paths of both aircraft. The investigation established that the controller had provided the AQUILA A-210 with traffic information regarding the AIRBUS A321 and had specifically instructed the light aircraft to cross behind it.
The pilot of the AQUILA A-210 stated that he believed he had the second aircraft in sight, though he later admitted this may have been an error due to low cloud cover. The investigation also reviewed the AIRBUS A321 crew's response, confirming that their actions were consistent with the company's technical manual and TCAS RA protocols.
Findings
- The pilot of the AQUILA A-210 acknowledged the instruction to cross behind the AIRBUS A321 but failed to execute the requested left turn.
- The AQUILA A-201 passed underneath the AIRBUS A321, triggering the TCAS RA.
- The AIRBUS A321 crew correctly followed the TCAS RA instructions and performed a go-around.
- The pilot of the AQUILA A-210 failed to comply with ATC instructions by executing a maneuver different from the one requested and authorized.