What happened
On July 16, 2018, a passenger charter flight operated by Bulgarian Air Charter, involving a MD-82 with registration LZ-LDM, encountered a critical situation while approaching runway 20 at Tarbes-Lourdes-Pyrénées Airport, France. The flight, which originated from Catania, Italy, was operating in challenging meteorological conditions characterized by heavy rain, thunderstorms, and gusty winds.
During the approach, the aircraft's flight profile became unstable. After the autopilot was disengaged, the aircraft drifted from the localizer and glide path. The captain eventually took control of the aircraft but elected to continue the approach despite the deviation. As the aircraft passed the runway threshold, the crew initiated a go-around maneuver. However, the transition was flawed; the engine thrust was not increased to the required TOGA power setting. Consequently, the aircraft continued to fly for approximately 1,680 meters without sufficient thrust, with the airspeed dropping toward a stall and the aircraft's altitude fluctuating dangerously low, reaching as little as 10 feet above the ground.
The investigation
The Bulgarian AAIU investigation examined flight data recorder (FDR) information, air traffic services data, and crew statements. The inquiry focused on the sequence of events from the moment the autopilot was disconnected through the failed go-around. The investigation analyzed the aircraft's configuration, including flaps, slats, and engine thrust settings, as well as the impact of the severe weather on the crew's decision-making and flight technology application.
Findings
- The primary cause of the event was pilot errors in crew coordination and flight technology application during the approach and go-around procedures under adverse weather.
- The co-pilot, acting as the pilot flying (PF) initially, failed to maintain the stabilized approach criteria and did not initiate a timely go-around.
- Upon taking control as the pilot flying, the captain failed to apply the necessary engine thrust for the go-around maneuver.
- The co-pilot, acting as the pilot monitoring (PNF), failed to monitor engine parameters, airspeed, and altitude, and did not alert the captain to the critical reduction in speed.
- Severe weather conditions, including heavy rain and gusty winds, contributed to the destabilization of the approach and increased crew stress.
- The aircraft's speed decreased to near-critical levels, reaching approximately 116 knots at a pitch of 15 degrees.