What happened
On September 23, 2009, an Airbus A319-111, registration F-GRHU, operating a passenger flight from Moscow to Paris, initiated a go-around at Paris Charles de Gaulle airport. The crew was performing an ILS approach to runway 27R when weather conditions deteriorated, reaching the decision height of 200 feet without visual contact with the runway.
During the go-around maneuver, the pilot flying attempted a "soft" go-around by advancing the thrust levers gradually rather than to the full TOGA detent. Because the levers were not moved to the TOGA position, the aircraft's automated go-around modes failed to engage. As the crew transitioned through various flight phases, the pilot engaged the autopilot (AP) while the aircraft was still in a descent mode. This resulted in the autopilot commanding a nose-down pitch, causing the aircraft to descend to a minimum altitude of 76 feet and triggering a GPWS "Sink Rate" warning. The crew eventually stabilized the aircraft and continued the climb.
The investigation
The BEA investigation focused on the automation settings, the crew's flight path management, and the specific thrust lever positions used during the maneuver. Investigators examined the flight crew's use of the Flight Management Guidance System (FMGS) and the interaction between manual inputs and the autopilot. The investigation also reviewed the company's standard operating procedures (SOPs) and identified discrepancies between the manufacturer's documentation and the airline's internal manuals regarding go-around execution.
Findings
- The primary cause of the altitude loss was the engagement of the autopilot in an inappropriate mode.
- The failure to activate the correct go-around modes was a direct result of the thrust levers not being moved to the TOGA detent.
- There was a lack of adequate monitoring of the aircraft's pitch attitude by the crew.
- Contributing factors included imprecise wording in the airline's operational procedures and a tendency for the crew to adapt procedures to meet operational constraints (such as passenger comfort or minimizing altitude gain) rather than strictly following safety-critical protocols.
- The investigation also noted that the co-pilot's attention was divided by the need to communicate with Air Traffic Control during the critical phase of the maneuver.