The French BEA released the final report regarding the runway excursion accident involving an Airbus A321 at Lyon, France. The aircraft touched down late on a wet runway following an unstabilized tailwind approach at high airspeed.
The accident happened on March 29, 2013. The Airbus A321-111, registered SX-BHS, operated flight ML7817 from Dakar, Senegal to Lyon, France with an en route stop at Agadir, Morocco.
The crew performed an ILS Category 1 (CAT I) approach to runway 36R at Lyon Airport. The weather conditions are such that operating low visibility procedures (LVP) prevailed.
During the transition from the stabilization of height 1000 ft, the aircraft speed was 57 knots greater than the approach speed. At 140 feet, an inappropriate increase in thrust by autothrottles maintained the aircraft at a high speed.
The aircraft landed long and the touched down 1600 meters after the 36R threshold. The plane overran at a speed of 75 knots and came to rest about 300 meters beyond the runway end.
Causes of the Accident:
Continuing an approach below the stabilisation height with a speed significantly higher than the approach speed shows that the crew were not adequately aware of the situation, even though they mentioned several times their doubts on the marginal meteorological conditions and on the difficulties in reducing the aeroplane’s speed.
Continuing this unstabilised approach at an excessive approach speed triggered, below 150 ft, an uncommanded increase in engine thrust. The crew’s delayed A/THR reduction below 20 ft made it impossible for the aeroplane to slow down sufficiently for about 15 seconds after passing the threshold.
After descending through 20 ft, the copilot’s inappropriate flare technique and the dual input phenomenon caused by the Captain significantly lengthened the flare phase. The remaining runway distance after the touchdown made it impossible for the aeroplane to stop before the end of the runway.
The following factors contributed to continuing the unstabilised approach and the long flare:
- a flight duty period of nearly 15 hours which likely led to crew fatigue;
- incomplete preparation of the approach which meant the crew was not aware of the risks on the day (tailwind, wet runway);
- the non-application of ATC procedures that require controllers to ensure aircraft are provided with localiser interception at the latest 10 NM from the runway threshold, with a maximum convergence of 30° and a maximum speed of 160 kt;
- partial application of standard procedures (SOP), impaired task sharing and degraded CRM, which meant the crew was unable to manage optimally the aeroplane’s deceleration. These factors contributed to a progressive deterioration in situational awareness that meant that they could not envisage rejecting the approach and landing;
- the A/THR anomaly which maintained the aeroplane at a high energy level during the landing phase;
- an inadequate procedure for taking over the controls that led to the dual input phenomenon.
The following organisational factors contributed to the crew’s poor performance:
- the choice of flight crew recruitment profiles by the operator, motivated by economic considerations, and inadequate airline conversion, led to operating aeroplanes with crews that were relatively inexperienced on type and in their roles as captain or copilot;
- improper and inappropriate application of the regulatory provisions that allow an extension of flight duty time in case of “unexpected circumstances” without taking into account the predictable risk of excessive fatigue for the crew;
- the absence of suitable initial oversight which made it impossible for the HCAA to focus on the predictable potential operational weaknesses of Hermes Airlines.
- BEA Final Report (PDF)