The crew of Hermes Airlines flight ML7817 made a Category 1 (CAT I) ILS approach to runway 36R at Lyon Saint-Exupéry Airport.
The meteorological conditions were such that low visibility procedures (LVO) were in place.
On passing the stabilisation height at 1,000 ft, the speed of the Hermes Airlines flight ML7817 was 57 kt above the approach speed.
At 140 ft, an inappropriate increase in thrust by the autothrust maintained the aeroplane at high speed.
The flare was long and the Hermes Airlines flight ML7817 touched the runway at 1,600 metres past the 36R threshold.
The aeroplane overran the runway and came to rest approximately 300 metres after the opposite threshold.
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 of Hermes Airlines flight ML7817 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.