Serious Incident  G-JZHL

2022-018: It is recommended that the UK Civil Aviation Authority, in conjunction with other regulatory authorities, develop a set of technical specifications and, subsequently, develop certification standards for an on-board system that will alert the crew of an aircraft to abnormally low acceleration during take-off.

The joint EUROCAE / RTCA working Group 129 (WG129) has met on a number of occasions during 2024 in both Plenary and working group meetings. The concluding output of these meetings and work was to present an Internal report (IR) to the EUROCAE Technical Advisory Committee (TAC) and RTCA Program Management Committee (PMC) in November and December 2024 respectively.

The purpose of the IR was to conclude that the technology had advanced sufficiently since the conclusion of WG94 in 2015 to enable the group to go on and create a MOPS or MASPS for take off performance monitoring and Alerting.

Both EUROCAE TAC and RTCA PMC agreed with our conclusion and revised ToR that the group could now progress to discussing and creating a standard. The group agreed that a revised title of Take-off Performance Awareness and Alerting System (TOPAAS) would better describe the system.

A series of working and plenary meetings has been agreed and set up for 2025 with the group already working well on different sections of the standard. As this EUROCAE working Group is set to continue developing a MOPS for this standard, the Civil Aviation Authority would like to propose that our next update to AAIB recommendation 2022-018 shall be provided by the end of February 2026.

Open - Tracked actions

February 2026

2022-019: It is recommended that the UK Civil Aviation Authority encourage all UK Air Operator Certificate holders to implement into their flight data monitoring programme algorithms to detect the precursors relevant to the monitoring of take-off performance detailed in the European Operators Flight Data Monitoring Document, Guidance for the implementation of flight data monitoring precursors.

In response to the recommendation from this serious incident the CAA will engage with stakeholders and regulatory bodies to identify parallel workstreams and seek to maximise the safety benefit of FDM programmes.

The CAA has continued to hold cross-industry FDM forums, with the most recent taking place in May 2024, where all operators were asked to capture performance data and identify any low acceleration events. During the forum, statistical analysis from one operator was shared to highlight the clear benefit and value in using FDM as a tool to identify low acceleration outliers.

Progress is being made to better understand these events and agree a common standard for data collection that can be rolled out to industry. Our Safety Intelligence team have thus far analysed 4 years’ worth of historical data which was sent to us from one operator and work is ongoing to determine the best point on the take-off roll to capture the acceleration.

The CAA continues to investigate a method by which operators could pool take-off performance data, in order to quantify cross-industry low acceleration events. As per our previous comments, this data would be presented as a pool, categorised only by airport and runway. The concept is that each operator would only be able to see their data relative to an unidentifiable industry pool but would allow the CAA and operators to see cross-industry airport and runway hotspots (if they occur).

The European Operators Flight Data Monitoring Document, Guidance for the implementation of flight data monitoring precursors was distributed to operators encouraging them to compare their current FDM events against those contained in the document. At present, the CAA has not received any feedback or comment from operators regarding this document.

The CAA intends to host another cross-industry FDM forum in Q2/2025. The aim is to provide an update on the progress made in the specific area of take-off performance monitoring and to continue the work already conducted.

The Civil Aviation Authority would like to propose that our next update to AAIB recommendation 2022-019 shall be provided by the end of February 2026. This will allow extra time for data collection to be progressed, both externally from industry and internally within the CAA, to identify common standards for data collection and a safe and secure system to receive such volumes of data.

Open - Tracked actions

February 2026