The Airbus guidance provided in the flight crew techniques manual and other manuals for helping A330 flight crews decide whether to continue or reject a take-off did not refer to unreliable airspeed indications.
The safety action should improve pilot monitoring of airspeed indications, increasing the likelihood that unreliable airspeed indications would be detected as early as possible during the take-off. It should also help rapid decision-making to some extent as a result of improved flight crew awareness and understanding of the characteristics of unreliable airspeed indications. While there continues to be no guidance on decision-making for unreliable airspeed indications detected after 100 kt, the Airbus approach emphasises detection and action prior to 100 kt rather than relying on decision-making after that point. Accordingly, it is important to ensure that all flight crews will both detect and understand the indications before reaching 100 kt, which is the principle that underpins another safety issue (AO‑2018‑053‑SI‑10). Accordingly, the ATSB considers AO‑2018‑053‑SI‑16 to be adequately addressed.
On 15 March 2021 Airbus issued a flight operations transmission to operators of all Airbus aircraft to:
… highlight that it is essential to actively monitor the airspeeds during every takeoff roll, in order to detect any unreliable airspeed situation as early as possible. In case of unreliable airspeed, the crew is expected to safely reject the takeoff.
The flight operations transmission stated:
Flight Crews should be ready to reject the takeoff in case of any detected unreliable airspeeds.
On 30 March 2021 Airbus issued an operations training transmission to all operators of Airbus aircraft and approved training organisations recommending training to mitigate the risks associated with unreliable airspeed events at take-off. The information was integrated into the Airbus flight crew training standards in a new section titled Unreliable air speed at takeoff on 20 April 2021. The guidance recommended the inclusion of training elements related to:
On 5 August 2021 Airbus advised that the following was added to the flight crew techniques manual:
During the take-off roll, the PM [pilot monitoring] monitors the PFD [primary flight display] and ENG [engine] indications to ensure early detection and appropriate decision making in the case of malfunction. By scanning the airspeed indications, the PM will detect any inconsistent airspeed indications between instruments or absence of airspeed indications.
In January 2022 Airbus published an article in its Safety First magazine titled Training Pilots for Resilience which gave detailed information and guidance about resilience training for flight crews to ‘help them to overcome the startle effect and temporary loss of situational awareness, to react in a controlled manner, and to continue a safe flight.’
The Australian Transport Safety Bureau encourages all manufacturers and operators of larger air transport aeroplanes to consider what types of unreliable airspeed events can occur, how the information is presented to flight crews, and what responses are the safest in different phases of the take-off and in a range of potential situations. Aircraft alerting systems, flight crew procedures, and flight crew training should be designed to provide sufficient assurance that flight crews become aware of and understand how to appropriately respond to unreliable airspeed on take-off in a timely manner.
A copy of the Safety Advisory Notice is available here.
