On 17th November 2021, an F-35B ditched into the sea on take-off from HMS Queen Elizabeth in the Eastern Mediterranean during operation FORTIS / CSG21. The basic cause of the accident was understood very quickly but the full board of enquiry report published recently highlights multiple contributing factors and reveals broader issues with UK Carrier Strike capability.
The F-35B aircraft ZM152, also known by its construction number, BK-18 flown by an RN pilot known as Lt ‘Hux’ was attempting to take off from the carrier for a training sortie. Due to a protective engine blank being left in the intake duct, the engine was only able to generate 55% of the thrust needed for the aircraft to take off from the ski ramp. Realising something was amiss, the pilot attempted to abort but it was too late and the jet was about to fall off the ramp when he was forced to eject. Following the successful ejection, Hux descended by parachute, fortunately landing on the flight deck, avoiding the extreme hazard of landing in the water and being run over by the ship. He suffered cuts to his neck and other minor injuries but was not seriously hurt. The aircraft was seen to be afloat as the ship passed by but sank shortly afterwards.
Small mistakes, big consequences
The report specifies a series of small issues that contributed to the accident. Some are part of a systemic force-generation problem while others might be seen as typical lessons learned through experience with new jets on a new carrier conducting its first long deployment.
A key misstep was the way that red gear items used to protect the aircraft were handled by engineers. The storage solution and logging methods for recording the issue or return of red gear was weak and there was no system in place that would immediately make it obvious one item must still be on an aircraft due to fly. The risks from FOD (Foreign Object Damage) were always treated very seriously but red gear was perceived more as a risk to other aircraft rather than the aircraft it was fitted to. This is despite the fact that 4 instances of red gear being sucked into F-35 engines had been recorded by US operators although they had been very fortunate, none resulted in the loss of an aircraft.
The design of the red gear for the F-35 had gone through various iterations and was not entirely satisfactory. Ironically the text ‘Remove before flight’ was printed on the intake blanks by the manufacturer but the characters were found to peel off and present a FOD hazard so 617 Squadron engineers removed the lettering. A pop-pin used to secure the intake cover in place was not always used and there were numerous instances of red gear being blown off aircraft on the flight deck, including on the day of the accident and several had been lost overboard.
Due to these problems, red gear was not routinely fitted to aircraft on the flight deck when the ship was at sea. In this instance, the Government Special Access Programme Security Officer (GSSO) responsible for maintaining the secrecy of some aspects of the F-35, ordered them to be fitted for the visit to Oman and the transit of the Suez Canal, although gave no instruction when they should be removed. The intake ducting is designed to shield the fan at the front of the F-35’s engine from radar in order to help maintain the aircraft’s stealth. This feature is covered when it might be viewed close up by those without security clearance.
The reason the engine blank was left in the engine was primarily down to faulty assumptions made by two engineers tasked with conducting routine maintenance on BK-18 which was due to fly the following morning. The combined Post Operation Servicing (POS) and Before Operation Servicing (BOS) schedules mainly involved thorough inspections. The first engineer went onto the flight deck and conducted his work which involved removing the right blank to inspect the engine. When work was complete he took the single blank back to stores but could not carry the full set of red gear. The second engineer was delayed as he was required to assist with moving containers in the hanger so there was no handover. Working alone he did not see the left-hand blank which had likely been blown down the duct and was almost invisible. At night 617 engineers believed they were not allowed to use white light torches so as to preserve the night vision of the bridge team – the use of coloured light further reduced the chance of spotting the blank.
Early the following morning, 617 engineers conducted a mass removal of blanks on UK aircraft but also missed the blank stuck down the left duct of BK-18. Due to the posturing of (Russian) assets in the Eastern Mediterranean, the air wing was held at readiness for Combat Air Patrols (CAP) as it emerged from the Suez Canal. The pilot of BK-18 was scheduled to lead 2 sorties as part of an instructor qualification work-up, supervised by an experienced instructor flying in BK-21 as the number two. The pilot and the ‘see-off’ team that prepared the aircraft just before take-off also failed to spot the rogue blank. Tired engineers at all levels of seniority fatigued after 6 months at sea made small but understandable errors and the squadron had become too lax about handling red gear.
A people problem
The biggest contributory factor that led to a small error resulting in a costly and serious accident was a lack of people and a lack of carrier operating experience. It was not just a shortage of aircrew (although the Defence Secretary admitted in 2022 the UK had a combined total of just 33 pilots trained to fly the 29 F-35s then in its possession, including three foreign pilots on exchange). To generate the 113 personnel needed for FORTIS, 617 had to borrow 15 people from 207 Squadron. 14 of the engineers that deployed were very inexperienced and joined directly from Phase 2B training. Only 55% of the whole unit had ever spent time on a carrier and 23% had not completed the Embarked Forces Sea Survival Course (EFSSC) which is supposed to be mandatory preparation for sea time.
Unlike RN aircraft engineers, their RAF counterparts did not qualify in flight line servicing during Phase 2B training. Either they needed to be fitted onto the limited spaces available on RN courses or get by with on-the-job training. This meant 617 had to borrow engineers from 207 which disrupted the Lightning Force as a whole and reduced cohesion and efficiency. It also placed even greater demands on the core of experienced personnel, increasing tiredness. The restrictions imposed on the whole ship’s company and limited opportunities for runs ashore as a result of COVID also compounded the fatigue.
A high turnover of people exacerbated the issues, especially in senior posts. The Senior Engineering Officer job in 617 Squadron had been filled by 5 Officer’s in 2 years leading up to the deployment. This was a Sqn Ldr/Lt Cdr post but had to be filled by two less experienced officers for a period. The Squadron Warrant Officer Engineer (WOEng) had 4 years Lightning experience but only joined the Squadron 5 months before FORTIS and had never been to sea. Only one of the personnel in the four key engineering management positions of SEngO, two JEngOs and WOEng had completed more than one of the carrier workup embarkations.
Slightly ludicrously, wherever the US Marine Corps Squadron VMFA-211 also embarked on the ship is named in the report, it has been redacted, although it is quite obvious which unit is being referred to. The methods and establishment of VMFA-211 provide a very useful benchmark for comparison and 617 Squadron comes off badly. It is no coincidence that it was one of the 8 UK jets and not one of the 10 US jets that suffered this particular avoidable accident. 113 personnel of 617 Squadron were embarked for the deployment (12 of them were repatriated at various stages for personal or health reasons and not replaced) while VMFA-211 brought 255 people. 617 effectively had 14 personnel to each jet while the Marines had 25 per jet. If we assume the USMC has correctly determined the optimum support requirement for sustained F-35B operations at sea, then the UK squadron began the deployment a whopping 44% understrength.
In preparation for FORTIS, the CSG conducted 10-day exercise Strike Warrior in early May. This provided a little further maritime experience to 617 and established many of the routines for that would be used in FORTIS. A lesson identified from the exercise was that insufficient engineers were available to conduct flight line ops and aircraft rectification concurrently. Despite being a deployment that had been in the planning for 3 years, it was then too late to properly address the pressures that 617 engineers would inevitably come under on a 7-month deployment.
The pitfalls of part-time carrier aviation
In April 2000 the Joint Force Harrier was formed and the RN permanently gave up direct control of its fixed-wing aviation. Subsequently, when the Harrier was replaced by the F-35 Lightning and selected as the jet to fly from the aircraft carrier, the joint force was well established and the arrangement continued. To compound the pressure on the Lightning Force, the F-35B was also double-hatted as the replacement for the RAF Tornado force. This was the result of a fudge created by politicians failing to appreciate the exceptional value of naval aviation and more broadly, fund defence adequately. The effects of this continue to reverberate and impact the development of carrier strike today and can even be seen as an aggravating factor in the loss of the jet in 2021.
This is not an inter-service issue as such and at the time of the accident 617 was commanded by a Royal Navy aviator and the Squadron is a mix of RN and RAF personnel. The joint force concept works harmoniously at a micro level but the problem is at the macro level with the expectation on the force to perform in two separate and specialised roles. There is a constant tension between the need to force-generate for carrier operations while at the same time being tasked to operate from land on deep strike or air defence missions. Despite being in the early stages of development, the Lightning Force has already sent aircraft to Cyprus and Estonia to participate in live operations. As the number of jets and people grows this should ease the pressure a little but without a focus on a particular role, the jack of all trades risks being a master of none.
The ‘Dambusters’ 617 Squadron is arguably the RAF’s most high-profile unit, flying the most potent 5th generation aircraft possessed by the UK. Surprisingly the report admits the squadron was under strength, morale was low, there were insufficient Quality Assurance checks being conducted at Marham and general readiness for FORTIS was lower than COMUKCSG had been led to believe.
On the surface, it may appear there is little difference from an aviation perspective between carrier or land-based operations. As the accident demonstrates, HMS Queen Elizabeth is not just a floating equivalent of RAF Marham. In fact, the working environment, the increased level of risks to people, added procedural complexity and the pace of operations it very different at sea. For example, the simple and apparently minor issue of red gear storage arrangements on the carrier differing from what was routine ashore was a contributing factor, together with crew fatigue and inexperience. It is not possible to eliminate every mistake but ensuring the investment in UK carrier strike reaches even half of its potential and delivers maximum effect safely while maintaining the promised high readiness level, demands continual practice and focus.
The need to regularly rehearse these specialist skills goes beyond the squadron personnel working on the carrier but to the pilots and the wider Royal Navy fleet that need to frequently exercise the procedures and develop tactics for the maritime air battle. US Navy aviation personnel spend their time focused on operating at sea and are generally not expected to conduct land-based operations for sustained periods, that being the job of the US Air Force. Despite being wholly dedicated to their art and their aircrew considered to be amongst the elite of aviators, the USN still suffers occasional accidents as aircraft carriers are an inherently dangerous environment.
Following the all-out effort of FORTIS, F-35s were embarked on RN carriers for just 18 days in 2022 (11-29 Nov). This pitiful output becomes something of a vicious circle as the length of time between embarkations means a proportion of this precious time has to be spent on pilot carrier qualifications. Reacquainting pilots with the basics comes at the expense of conducting more complex sorties as well as integration with the fleet. This issue will clearly be exacerbated if there are too few support personnel and a high turnover of people is permitted, accelerating the loss of what are already perishable skills.
Air Marshall Steve Shell, responsible for the investigation admitted that The Lightning Force “has not yet reached the critical mass at which experience can be retained through posting cycles whilst still offering attractive job opportunities… and force growth cannot be maintained while front line squadrons are deployed. Until critical mass is reached, Defence must recognise the trade-offs between readiness, growth and safety”. HMS Queen Elizabeth will shortly deploy on CSG23 operating in northern European waters. It will be instructive to observe how many jets are embarked, and what operational tempo is maintained.
The second frontline F-35 unit, 809 Naval Air Squadron was supposed to be stood up in April this year but this has now slipped to December 2023 due to shortages of people. Although badged as a Fleet Air Arm unit, it will be another joint squadron and will operate in exactly the same way as 617. Full Operating Capability (FOC) for the Lightning Force is supposed to be achieved by 31 March 2025 but the delay to 809 does not bode well. It would seem that the post-COVID people shortages undermining the RN are just as problematic for the RAF, already beset by a lack of pilots thanks to the well-documented failures in the UK Military Flying Training System.
Several other minor deficiencies were revealed by the incident including an issue with limb restraints on the ejector seat that could have been more serious had it not been an ejection at slow speed. The pilot’s lifejacket also failed to inflate properly when later tested. The medical response was rather confused and there was a lack of clear communication within the ship in the immediate aftermath of the incident. The FOST syllabus did not include training on how to respond to an ejection close to the ship. Some of the data in the combat management system which should have formed part of the investigation was lost due to a lack of established procedures following an accident. Finally, the sonar locator beacon that was supposed to help locate the wreck on the seabed failed to activate, although in this case the exact position of the ditching was known making it fairly straightforward to pinpoint the wreck.
The loss of a jet valued at £81.8M and the subsequent £2.3M salvage operation is clearly very serious but fortunately, there were no major injuries or loss of life. If there is a silver lining to this cloud it comes from the multiple lessons that will be learned, potentially saving lives in future. Assuming the message that running short-handed with too many inexperienced people is addressed properly then it can only help make for a more effective capability in the long run.