The available Cross Crew Qualification and Mixed Fleet Flying guidance did not address how flight crew might form an expectation, or conduct a ‘reasonableness' check, of the speed/weight relationship for their aircraft during takeoff.
The Flight Safety Foundation has commenced education (initially through AeroSafety World article). There is no more that the ATSB can directly do until engineered systems are implemented and the appropriate experts (not based in ATSB) find solutions to the Human Factors side of it.
The Australian Transport Safety Bureau requests that the Flight Safety Foundation consider developing guidance to assist flight crews form appropriate mental models in respect of the weight and corresponding take-off performance parameters for a particular flight. The use by operators of mixed fleet flying increases the importance of that guidance.
The Australian Transport Safety Bureau requests the International Air Transport Association to encourage its members to develop guidance to assist their flight crews form appropriate mental models in respect of the weight and corresponding take-off performance parameters for a particular flight. The application by operators of mixed fleet flying increases the need for that guidance.
The ATSB recognises that the existing avionics technologies have as yet been unable to develop a take-off monitoring and alerting system. However, given that equipment unavailability, the ATSB remains concerned at the present lack of take-off performance monitoring guidance available to flight crews who are involved in mixed fleet flying. In that context, consideration was given to the most effective means of promoting relevant safety action among the world’s operators.
Ultimately, that means of communication was determined to be via a safety advisory notice (SAN) that sought the assistance of the International Air Transport Association (IATA) and Flight Safety Foundation (FSF). The intent was that those organisations would, through their members, be best equipped to address the safety issue. Hence, the ATSB issues the following SANs to IATA and the FSF.
In July 2009, Airbus announced in their Safety First magazine that they were developing a software package called the ‘Take-off Securing’ (TOS) function. The TOS function automatically checks the data being entered into the flight management and guidance system (FMGS) for consistency between the take-off parameters.
A check is carried out on the takeoff reference speeds entered into the FMGS against take-off limitation speeds calculated within the FMGS based on the aircraft weight. If the TOS function detects a discrepancy between these speeds, it alerts the flight crew by displaying a message on the FMGS display unit. On 28 May 2010, Airbus provided the ATSB with the results of a simulation of the TOS function for the A340 using the accident flight take-off performance parameters. The result is shown below [image of results showing "TO SPEED TOO LOW" warning in scratch pad]. On 28 October 2011, Airbus advised that they plan an additional development that will include functionality to check that the aircraft has sufficient runway length to support a safe takeoff.
The ATSB is satisfied that when installed in transport aircraft, the Take-off securing function will adequately address this issue.
