Management of the aeroplane’s energy on approach
This section sets out a few operational safety topics with respect to commercial air transport, principally involving large aeroplanes. These topics are illustrated with the latest reports published by the BEA and certain reports from foreign investigations which the BEA was involved in as accredited representative.
The crew have to pay particular attention to the management of the aeroplane’s energy from the beginning of the descent, and continue to do so during the approach up until landing. Whatever the level of automatic control chosen by the crew, notably during the final approach, they must be familiar with it and aware of the associated limitations. During the approach, the crew are expected to follow the instructions published in the AIP and those given by air traffic control. They must also comply with the procedures and techniques specified in the manufacturer’s and operator’s documents, notably with respect to the configuration and the reduction in speed, while at the same time, adapting to the operational context of the flight. The implementation of the CRM principles and in particular, appropriate monitoring by the PM, shall contribute to the management of the aeroplane’s energy.
Incorrectly managed energy exposes the crew to the risks of a runway excursion, a hard landing, landing before the runway, a tailstrike or even a stall.
1. Non-stabilized approach, long landing, runway overrun
The Embraer EMB145 registered F-HYOG ran over the end of the runway while landing at Paris-Orly on 20 October 2022 in stormy conditions. The investigation showed that weak CRM contributed to the final approach being flown at a speed which was too high, above the approach slope and in a different configuration to that specified in the briefing. The crew did not detect the change in wind direction with a tailwind component which had become significant. The PM’s uncoordinated intervention on the controls to the detriment of his required monitoring role, meant that the crew did not envisage carrying out a missed approach. This resulted in a long landing at high speed.
Links : Occurrence page | Report
2. Non-stabilized approach, activation of MSAW and Glide Slope alerts
The investigation into the incident to the Airbus A318 registered F-GUGM on 12 September 2020 during the approach to Paris-Orly showed that the crew who were not under any outside pressure, carried out a high-speed approach and continued with the landing despite being largely destabilized. The MSAW alert (Minimum Safe Altitude Warning available to air traffic controllers at certain aerodromes) and the Glide Slope alert (on the aircraft) were triggered during the approach. The investigation found that the crew carried out the approach outside the scope of SOPs and did not follow the flight profile recommended by the manufacturer. This profile enables the crew to manage the approach energy in a manner which is compatible with a safe landing. During the final approach, the crew’s focus on reabsorbing the excessive energy contributed to a deterioration in the monitoring by the PM. At 500 ft agl, the aeroplane was at a speed of Vref+26 kt. The report underlined that without being aware of it, the crew at this point, probably had very few mental resources available to deal with an unexpected event.
Links : Occurrence page | Report | Presentationn Video | “Safety Digest" informations sheet
3. Acquisition of a false glide slope signal on approach, increase in pitch attitude with autopilot engaged, activation of the flight envelope protections
The investigation into the incident to the Airbus A318 registered F-GUGD on 20 December 2019 on approach to Hyères showed that the crew had taken into account the tailwind threat for landing. However, they did not take into account the prior impact of this component on the approach path. In a short space of time, the crew tried to control the speed and intercept the glide slope from above. They progressively lost situational awareness: they did not detect that the aeroplane levelled off or the change in pitch attitude when the guidance system intercepted a false glide slope signal. The LOW ENERGY alert and the ALPHA FLOOR protection were activated.
Links : Occurrence page | Report | Animation | “Safety Digest” information sheet
4. PREDICTIVE WINDSHEAR warning on final, partial and subtle incapacitation of co-pilot during go-around, lateral and vertical flight path deviations, LOW ENERGY alert, conflict with a departing aeroplane
During the incident to the Airbus A350-900 registered F-HREV on 4 February 2020 at Paris-Orly, the captain, who was initially the PM, had to take the aeroplane’s controls in an uncoordinated manner during the missed approach phase following a WINDSHEAR AHEAD warning and the copilot’s (initially PF) subtle incapacitation. In this extremely dynamic phase, large variations in energy were observed, shown by several variations in altitude well above and below the go-around altitude along with the activation of the LOW ENERGY alert.
Links : Occurrence page | Report | Animation
5. Windshear, long landing, runway overrun on landing
In the night of 23 to 24 September 2022, the crew of the Boeing 737-400 registered EC-NLS, operated by Swiftair, were carrying out a mail commercial air transport flight between Paris - Charles de Gaulle and Montpellier - Méditerranée. The captain, in the left seat, was the Pilot Monitoring (PM), and the co-pilot, in the right seat, was the Pilot Flying (PF). An aircraft maintenance mechanic was also on board this flight, sat in the cargo area. After having prepared and carried out the briefing for an ILS approach to runway 30R, the crew were informed that the runway in use had been changed. They then prepared a VOR-DME approach to runway 12L. There was no briefing for the new approach. A storm cell was approaching the airport from the south-west. During the approach, the crew’s awareness of the presence of this cell was low despite available information. On short final, the captain and co-pilot agreed to change roles. The co-pilot, now the PM, did not carry out his monitoring tasks. When flying over the threshold, the aeroplane encountered windshear characterised by a sudden reduction in the tailwind. The crew did not detect this phenomenon and did not perceive its impact on the flight parameters. In particular, they did not observe that the aeroplane had exceeded the touchdown zone without coming into contact with the ground. The aeroplane touched down on the runway beyond the touchdown zone, at around 1,500 m from the threshold of runway 12L. It overran the runway and finished its run in Or lake.
Links : Occurrence page | Report | “Safety Digest” information sheet