Today (Friday 3rd March), the Air Accident Investigation Branch has issued its final report in to the tragic accident which occurred at the 2015 RAFA Shoreham Airshow which claimed the lives of 11 men. It can be downloaded here. As with all AAIB investigations, the report does not find blame but seeks to establish the causes of the accident and makes various safety recommendations that now must be analysed and reviewed by the Civil Aviation Authority and the wider UK Air Display Industry. It has been one of the largest investigations ever undertaken by the AAIB lasting 18 month and is presented over 400 pages.
The summary of the report reads:
At 1222 UTC (1322 BST) on 22 August 2015, Hawker Hunter G-BXFI crashed on to the A27, Shoreham Bypass, while performing at the Shoreham Airshow, fatally injuring eleven road users and bystanders. A further 13 people, including the pilot, sustained other injuries.
The AAIB investigation considered the circumstances in which the aircraft came to be in a position from which it was not possible to complete its intended manoeuvre, and the reasons for the severity of the outcome.
The AAIB recognises that as well as being enjoyed by large numbers of spectators and participants, flying displays are also considered to provide important economic and educational benefits .
A safe flying display relies on the training and experience of the participating pilots, the airworthiness of the aircraft, and the planning and risk management of the event. Regulations, guidance and oversight provide the framework for these activities.
The aircraft was carrying out a manoeuvre involving both a pitching and rolling component, which commenced from a height lower than the pilot’s authorised minimum for aerobatics, at an airspeed below his stated minimum, and proceeded with less than maximum thrust. This resulted in the aircraft achieving a height at the top of the manoeuvre less than the minimum required to complete it safely, at a speed that was slower than normal.
Although it was possible to abort the manoeuvre safely at this point, it appeared the pilot did not recognise that the aircraft was too low to complete the downward half of the manoeuvre. An analysis of human performance identified several credible explanations for this, including: not reading the altimeter due to workload, distraction or visual limitations such as contrast or glare; misreading the altimeter due to its presentation of height information; or incorrectly recalling the minimum height required at the apex.
The investigation found that the guidance concerning the minimum height at which aerobatic manoeuvres may be commenced is not applied consistently and may be unclear.
There was evidence that other pilots do not always check or perceive correctly that the required height has been achieved at the apex of manoeuvres.
Training and assessment procedures in place at the time of the accident did not prepare the pilot fully for the conduct of relevant escape manoeuvres in the Hunter.
The manoeuvre was continued and the aircraft struck the ground on the northern side of the westbound carriageway of the A27 close to the central reservation with a ground track at a slight angle to the direction of the road. When it struck the ground it broke into four main sections. Fuel and fuel vapour released from the fuel tanks ignited. In its path were vehicles that were stationary at, or in the vicinity of, the traffic lights at the junction with the Old Shoreham Road, and pedestrians standing by the junction.
The pilot did not attempt to jettison the aircraft’s canopy or activate his ejection seat. However, disruption of the aircraft due to the impact activated the canopy jettison process and caused the ejection seat firing mechanism to initiate. The seat firing sequence was not completed due to damage sustained by its firing mechanism during the impact. The seat was released from the aircraft and the pilot was released from the seat as a result of partial operation of the sequencing mechanism. Some of the pyrotechnic cartridges remained live and were a hazard to first responders until they were made safe.
The investigation found that the aircraft appeared to be operating normally and responding to pilot control inputs until it impacted the ground. Defects in the altimeter system would have resulted in the height indicated to the pilot being lower than the actual aircraft height at the apex of the manoeuvre.
Information included in a previous AAIB report indicated that there had been several cases involving the type of engine fitted to this aircraft where an un-commanded reduction in engine speed had occurred and subsequent engineering investigation did not establish a clear cause. This investigation was unable to determine whether a reduction in engine speed recorded during the accident manoeuvre was commanded by the pilot.
The aircraft’s engine was subject to a Mandatory Permit Directive (MPD) which imposed a calendar life on the engine type, and provided an option to extend that life using an Alternative Means of Compliance (AMOC). Proposals for an engine life extension using an AMOC inspection programme had to be approved by the regulator. Related tasks were being conducted by the maintenance organisation, but the regulator had not approved the operator or its maintenance organisation to use an AMOC to this MPD.
The investigation found that defects and exceedences of the aircraft’s operational limits had not been reported to the maintenance organisation, and mandatory requirements of its Airworthiness Approval Note had not been met. During prolonged periods of inactivity the aircraft’s engine had not been preserved in accordance with the approved maintenance schedule. The investigation identified a degraded diaphragm in the engine fuel control system, which could no longer be considered airworthy. However, the engine manufacturer concluded it would not have affected the normal operation of the engine.
The aircraft had been issued with a Permit to Fly and its Certificate of Validity was in date, but the issues identified in this investigation indicated that the aircraft was no longer in compliance with the requirements of its Permit to Fly.
The investigation found that the parties involved in the planning, conduct and regulatory oversight of the flying display did not have formal safety management systems in place to identify and manage the hazards and risks. There was a lack of clarity about who owned which risk and who was responsible for the safety of the flying display, the aircraft, and the public outside the display site who were not under the control of the show organisers.
The regulator believed the organisers of flying displays owned the risk. Conversely, the organiser believed that the regulator would not have issued a Permission for the display if it had not been satisfied with the safety of the event. The aircraft operator’s pilots believed the organiser had gained approval for overflight of congested areas, which was otherwise prohibited for that aircraft, and the display organiser believed that it was the responsibility of the operator or the pilot to fly the aircraft’s display in a manner appropriate to the constraints of the display site.
No organisation or individual considered all the hazards associated with the aircraft’s display, what could go wrong, who might be affected and what could be done to mitigate the risks to a level that was both tolerable and as low as reasonably practicable.
Controls intended to protect the public from the hazards of displaying aircraft were ineffective.
The investigation identified the following causal factors in the accident:
- The aircraft did not achieve sufficient height at the apex of the accident manoeuvre to complete it before impacting the ground because the combination of low entry speed and low engine thrust in the upward half of the manoeuvre was insufficient.
- An escape manoeuvre was not carried out, despite the aircraft not achieving the required minimum apex height.
The following contributory factors were identified:
- The pilot either did not perceive that an escape manoeuvre was necessary, or did not realise that one was possible at the speed achieved at the apex of the manoeuvre.
- The pilot had not received formal training to escape from the accident manoeuvre in a Hunter and had not had his competence to do so assessed.
- The pilot had not practised the technique for escaping from the accident manoeuvre in a Hunter, and did not know the minimum speed from which an escape manoeuvre could be carried out successfully.
- A change of ground track during the manoeuvre positioned the aircraft further east than planned producing an exit track along the A27 dual carriageway.
- The manoeuvre took place above an area occupied by the public over which the organisers of the flying display had no control.
- The severity of the outcome was due to the absence of provisions to mitigate the effects of an aircraft crashing in an area outside the control of the organisers of the flying display.
The AAIB has published three Special Bulletins (SB) highlighting areas of concern that required timely consideration.
SB 3/2015, published on 4 September 2015, 13 days after the accident, reported initial information about the occurrence.
SB 4/2015, published on 21 December 2015, dealt with the safety of first responders to the accident scene, the maintenance of ejection seats in historic ex-military aircraft and issues regarding the maintenance of ex-military aircraft on the UK civil register. Seven Safety Recommendations were made.
SB 1/2016, published on 10 March 2016, considered the risk management of flying displays, minimum display heights and separation distances, regulatory oversight and piloting standards. It contained a further 14 Safety Recommendations, and was published to inform the air display community ahead of the 2016 air display season.
A further 11 Safety Recommendations are made in this report.
Various interested parties from the UK Air Display Industry have issued statements today The organisers of the RAFA Shoreham Airshow issued the following statement:-
Following the publication of the final AAIB report into the Shoreham Airshow crash, the thoughts and sympathies of everyone associated with the Airshow are with the families of the victims on what will understandably be an emotional day.
The report clearly confirms that a series of errors by an experienced and fully authorised pilot were the cause of the tragic crash on 22 August 2015.
The Shoreham Airshow has been an important part of the local community for 26 years, raising over £2million for charity. The organisers always worked hard to ensure the event was both safe and successful. Our main aim in 2015 was to do just that, but there are findings in the report that will require further analysis and reflection.
The report also contains important recommendations for the CAA, as well as the wider airshow industry, and these must be noted carefully. Any recommendations made by the AAIB that are aimed at improving the safety of air displays can only be welcomed.
The organisers of the Airshow will continue to participate in the ongoing inquest as an interested party.
The British Air Display Association has reacted issuing the following statement on its website:-
The British Air Display Association:
- Welcomes the conclusion to the very lengthy AAIB Investigation process.
- Hopes that it will now provide a degree of understanding and closure for the families involved to whom we have offered our continued sympathies and sincere condolences.
- Trusts that this will now enable a speedy conclusion to any further investigations and enable the Coroner to fulfil due process.
- Notes that AAIB found no conclusive causal factors arising from either maintenance or organisational issues.
- Recognises, as with so many human endeavours, that Human Factors played a considerable part in this tragic accident
- Believes that the Management Team of the Shoreham Airshow collectively delivered an event in accordance with all CAA Guidance and Regulations extant at the time.
- Is an organisation committed to improving safety and standards so we look forward to engaging with any DfT review of UK Air Display flying called for in the report, noting that a huge amount of work has already been undertaken to identify measures to enhance safety and that great care must be taken to ensure any new regulation genuinely delivers improved safety. BADA hopes that such a review will:
- Build upon the 60+ years of safely delivered airshows in the UK.
- Recognise the vital contribution the air display community has made:
- Inspiring young people into STEM (Science, Technology, Engineering, Mathematics) related careers in aerospace and defence.
- Energising and enriching local economies.
- Raising vast amounts for charities.
- Around 6 million spectators a year have enjoyed air displays in the UK and, whilst recognising that both the regulatory and management regimes must continue to keep safety issues under the closest review, fervently believes that the popularity of Airshows and the critical national purpose they serve must be preserved.
Dame Deirdre Hutton, Chair of the CAA, said:
The thoughts of those at the CAA remain with the families and friends of everyone affected by this terrible tragedy at this difficult time.
This was the first fatal air show accident involving members of the public in the UK for over 60 years. It is therefore essential that everyone involved in the delivery and oversight of air displays now plays their part in learning all the lessons that we can.
The AAIB has conducted a wide-ranging investigation over 18 months and has produced an extensive final report which clearly identifies the cause of this accident as the aircraft flying too slowly and not reaching the height necessary to complete the loop.
The CAA acted immediately following the accident in August 2015 carrying out a comprehensive review of civil air show safety and implementing a number of safety enhancements for the 2016 season. An independent, external panel of experts oversaw the review to ensure that all UK civil air displays operate at the very highest safety standards.
During its investigation, the AAIB published 21 recommendations for the CAA, all of which we have acted on. We are continuing with our programme of introducing further safety enhancements for this year’s flying display season. The final AAIB report contains a further 10 recommendations for the CAA, all of which we will action as a priority.
We are fully committed to ensuring that all air shows take place safely, for the six million people who attend them each year in the UK and for the communities in which they take place.