Serious Incident  G-JZHL

AAIB Recommendation transmittal

Date

29/09/2022

Status

Open

CAA Initial Update

Date

29/11/2022

The UK CAA accepts this Safety recommendation. In order to ensure any UK position is coordinated with other key aviation regulatory bodies, we have started engagement to determine what, if any, parallel workstreams are already in process. We have also started engagement with Organisations developing standards for Aviation Equipment to understand if they have already been approached to work towards an agreed MOPS for any design solution. Any future mandate that is associated with agreed technical specifications will require further consultation – ideally with a coordinated regulatory action.

A workshop with key UK airlines is planned for Q1 2023 to start the initial scope of a technical solution. This will be followed by OEM meetings and further regulator outreach to try and maintain common collective position. The consequences and viability of a UK only approach will have to be considered in due course if a more global consensus is not possible.

The Civil Aviation Authority would like to propose that our next update to AAIB recommendation 2022-018 shall be provided by the end of June 2023.

Status

Open

AAIB Classification

Date

27/01/2023

Status

Adequate - Open

CAA Update

Date

30/06/2023

The UK CAA, through our Design and Certification department, has been investigating any previous work into the development to monitor dynamic take-off performance with the ability to warn the pilot. The UK CAA has discussed the development in this area with the FAA and EASA; whilst we do not believe either of these authorities are engaged in any certification activity of dynamic take-off monitoring, they both recognise the risk and have both positively engaged with us.

In addition, the UK CAA presented this topic at the FAA InfoShare, where contact was made with US airlines, regulators, and OEMs. Following this, we have had a workshop with Southwest Airlines that have shared their algorithms, and a follow-up with Boeing Safety team to discuss Boeing activities to find mitigations for this type of event. These are ongoing relationships; the UK CAA are facilitating a link for UK B737 operators directly with Southwest safety department.

The UK CAA has recently written to EUROCAE, requesting that a proposal be tabled at the next council meeting or Technical Advisory Committee to consider re-opening this working group to prepare MOPS / MASPS, which could ultimately form the basis of regulatory action that could reduce the number of take-off performance events. 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 2024.

AAIB Classification

Date

31/07/2023

Status

Partially Adequate – Open

The practicality of developing 'dynamic' takeoff performance monitoring systems (TOPMS) was considered by EUROCAE WG-94, but activity stalled in 2015 primarily because of the perceived computational complexity of the problem. In recognition of this, the SR (and previous AAIB SRs on the subject) specifically refer to alerting crews to abnormally low acceleration, which could form the basis of a takeoff acceleration monitoring system (TAMS) using empirical data to achieve the desired safety outcome.

It is clearly beneficial that the CAA and other bodies have recognised the safety issue and are working to find solutions to address it, and it would be a welcome outcome if the previous difficulties associated with TOPMS could be overcome and, thereby, address the underlying safety issue. The AAIB is concerned, however, that a search for a dynamic solution may stall for the same reasons as before while diverting attention from consideration of the SR as written.

CAA Update

Date

23/02/2024

The UK CAA recently presented our proposal to the EUROCAE Technical Advisory Committee on 16th January 2024 for the continuation of their previous Working group 94 discussing Take off performance Monitoring. There was positive feedback post the presentation which EASA was also present and endorsed our proposal.

Post this meeting, the EUROCAE council reviewed our proposal and agreed to the creation of WG-129 to look at Minimum operational Performance specifications (MOPS) or Minimum Aviation System Performance Specification (MASPS) for a “Take Off Performance Monitoring (TOPM) System”.

The UK CAA has been allocated a place at this working group and we will arrange a meeting with the programme manager to look at a road map prior to a kick off meeting.

As this EUROCAE working Group has been agreed and is in its infancy, 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 2025.

AAIB Classification

Date

28/03/2024

Status

Partially Adequate – Open

CAA Update

Date

24/02/2025

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.

AAIB Classification

Date

25/04/2025

Status

Adequate - Open

The AAIB notes the advance in technology referred to in the CAA's response that should enable performance standards to be developed for monitoring takeoff performance. Although the proposed standards are not directed specifically at identifying takeoffs with abnormally low acceleration, it appears likely that they would capture the circumstances that led to the original recommendation.

CAA Update

Date

11/03/2026

Since our last response, EASA have published their NPA 2025-01 (RMT.0741) which the whole of the EUROCAE / RTCA group were encouraged to read and comment back on before the deadline of 03rd October 2025.

The joint EUROCAE / RTCA working Group (WG129 SC244) continues to hold weekly working meetings and quarterly plenaries to progress the Take off Performance Awareness and Alerting System (TOPAAS) MOPS document we have started since the acceptance of our Internal report which confirmed the maturity of the current technology.

We have recently attended Plenary no 9 which also includes the 4 plenary meetings which we used for the production of the internal report for the TAC. During this last meeting the group agreed to an extension to the deliverable date as progress with the MOPS had not been as expedient as we had hoped. Our revised date which we are requesting of the TAC for publication of the MOPS is March 2027. With this timeframe, we continue to push for a mature draft document by September 2026.

AAIB Classification

Date

26/03/2026

Status

Adequate - Open

AAIB Recommendation transmittal

Date

29/09/2022

Status

Open

CAA Initial Update

Date

29/11/2022

The UK CAA accepts this Safety recommendation. The UK CAA recognises that the identification of the correct threat line, which could lead to a runway excursion event, is an important part of any safety risk mitigation strategies for the Take-off Performance errors.

The UK CAA will seek to maximise the safety benefit of the FDM programmes by:

• Identifying FDM events that can be easily linked to take-off performance errors as ‘precursors’ to the undesired outcome (runway excursion).
• Agree on common trigger values that could be used to produce a wider data set to identify sector risks to share with all operators, subject to confidential protocols being agreed and accepted.

We plan to do this by working with large AOC organisations through dedicated workshops and publish FDM ‘best practice considerations’ by the end of 2023.

The Civil Aviation Authority would like to propose that our next update to AAIB recommendation 2022-019 shall be provided by the end of June 2023.

Status

Open

AAIB Classification

Date

27/01/2023

Status

Adequate – Open

CAA Update

Date

30/06/2023

The CAA wrote to key airlines in December 2022 describing the safety concern and the activities we are considering. The letter contained information on current reliance on the human barrier to avoid the safety risk manifestation, and potential to use FDM data to detect the precursors or undetected events. The letter was well-received, and all agreed to support any associated initiatives.

The CAA hosted a preliminary workshop for the main airlines in January 2023, which introduced the CAA Bow Tie and barriers/controls. The workshop agreed an FDM workstream would be launched to determine what common markers could be used to ‘measure’ the size of the safety concern, and potentially identify unknown ‘near-misses’.

Other UK airlines are also active in investigating FDM potential to measure reduced performance margins. The various FDM threads will be brought together via the FDM group, including possible amendments to CAP739.

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 2024.

AAIB Classification

Date

31/07/2023

Status

Partially Adequate – Open

The AAIB acknowledges the work being done by the CAA to address the Safety Recommendation and trusts that the precursors in the guidance document referred to in the recommendation will aid the search for common markers.

CAA Update

Date

23/02/2024

Following the introductory workshop in December 2022, the CAA hosted two further workshops relating to Take-Off Performance. The second of these, held on the 21st November 2023, specifically addressed the use of Flight Data Monitoring to assess take-Off Performance issues, including how to identify pre-cursor events. The purpose of the workshop was to encourage the use of FDM for two purposes:

1. To quantify, using historical data, the number of previously unknown take-off performance events that have occurred.
2. To encourage operators to analyse new data for Take-Off Performance events.

The outcome from the workshop was that operators would analyse their historical data for low acceleration events. The CAA will investigate a method by which operators could pool takeoff performance data, in order to quantify cross-industry low acceleration events. 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).

Although the document referenced in the AAIB recommendation (European Operators Flight Data Monitoring Document, Guidance for the implementation of flight data monitoring precursors) is a thorough and useful reference, there remains challenges to effectively
measure some of the events or the associated risk exposure contained within the document recommendations. This document has been distributed to the larger airlines to encourage
them to compare their current FDM events against those contained in the document. The smaller aircraft operators (corporate airlines) have also been engaged through the relevant liaison group.

The CAA will be restarting the cross-industry FDM forum in Q2/2024 which is expected to continue the work already conducted in the specific area of take off performance monitoring as part of a wider agenda.

AAIB Classification

Date

28/03/2024

Status

Adequate – Open

CAA Update

Date

24/02/2025

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.

AAIB Classification

Date

25/04/2025

Status

Adequate – Open

CAA Update

Date

31/03/2026

The CAA has continued its engagement with industry through various working groups such as the Flight Ops Liaison Group (FOLG) to emphasise the importance of effective flight data monitoring programmes to identify take-off performance related events, particularly abnormally low acceleration during take-off.

Furthermore, to support and ensure wider dissemination of the message, the BALPA Flight Safety Committee was provided with a detailed briefing of the CAA’s ongoing work in this area.

Analysis was also undertaken by our Safety Intelligence team, which reviewed four years of historical flight data provided by a single operator to determine the optimal point on the take-off roll to capture acceleration. In collaboration with the operator, the aim was to identify any low acceleration outliers, investigate the causes and detect any trends associated with certain locations, runways or aircraft.

The study concluded that the CAA is not in a position to specify a single value for operators to incorporate within their Flight Data Monitoring programmes, but the results showed the most appropriate point for capturing acceleration lies between the range of 80kts and peak acceleration. While the analysis provided an indicative range for the optimal point of acceleration capture, it also highlighted that some events could be missed or hidden depending on the statistical analysis tools used. It is therefore recommended that each operator determines, validates, and continually refines their own alerting criteria to ensure optimal data capture for their specific operation.

The aim is to encourage operators to apply statistical modelling to this data and identify any outliers and instances of low acceleration that fall outside three standard deviations from the mean and conduct further investigations.

To conclude Safety Recommendation 2022-019, the Civil Aviation Authority proposes to formally document the above findings by means of a Safety Notice. It will require operators to reviewing the effectiveness of their Flight Data Monitoring programme in this area.

The Safety Notice will also provide guidance to operators on the procedures and training to ensure SOP adherence during technical or environmental distraction. It will be issued by Friday 29th May.

AAIB Classification

Date

27/04/2026

Status

Adequate – Open