First trials of F-35 aboard HMS Queen Elizabeth begin this autumn

In late August HMS Queen Elizabeth will leave Portsmouth for her Westlant 18 trip. The ship will be away for around four months and, although not an operational deployment, this will be her longest and most demanding period at sea so far. The centrepiece of the deployment will be the fixed-wing First of Class Trials (FOCT) with F-35Bs touching down on her deck for the first time. In this article we look at the preparation and plans for the flying trials.

From simulator to real world

Since 2007 a great deal of work has been done in the F-35 QEC integration facility at BAE Systems at Warton. This £multi-million investment includes an F-35 cockpit and a simulator replicating the Flying Control (Flyco) office in the after island of the QEC. Using these tools it been possible to test the behaviour of the aircraft and how it interacts with the aviation systems fitted to the ship, and make changes to design where required.

The Landing Signals Officer (LSO) provides advice to the pilot to assist with safe recovery to the ship. In the simulators, the pilots and LSOs have been able to build up experience and develop the operating procedures for managing F-35B launch and recovery from the ship.

Advances in computing power and the sophistication and accuracy of modelling and simulations have helped to mitigate much of the risk involved with integrating a new aircraft with a new ship. The QEC were designed to operate the F-35 from the outset, her spacious decks and the experiences of the USMC, already operating the F-35B at sea, give every reason for confidence the flight trials will be successful.

Flyco and the LSO workstation, part of the F-35 QEC integration simulator at BAE Systems facility at Warton, Lancashire. (Photo: BAE Systems)

The F-35B cockpit simulator at Warton, part of the most sophisticated flight simulator BAES has ever built. (Photo: BAE Systems)

Preparing for carrier aviation without carriers

Despite the loss of the RN’s aircraft carriers in 2010, unique carrier aviation and combat flying skills have been successfully kept alive by a careful strategy developed by the Fleet Air Arm. Adding to the legacy experience flying the Sea Harrier and Harrier GR7/9, selected RN pilots have served in the US Marine Corps flying the AV-8B Harrier and in the US Navy flying F/A-18 Super Hornet. This means today there are about 60 qualified RN fast jet pilots, with about 20 other pilots at various stages in the training pipeline. The RN currently has 8 fully trained F-35 pilots and the RAF will have 18 by the end of this year. Although based at RAF Marham and 617 being an RAF-badged squadron, the UK Lightning Force is a truly joint effort. An RN pilot slated to become CO of 617 shortly which will have a total strength of 14 pilots. Of these, 2 RN and 2 RAF pilots are ab initio, the F-35 is the first frontline aircraft they have trained on.

During QE’s last brief period at sea, Hawks of 736 Naval Air Squadron, played the part of F-35s so that the flight controllers onboard could rehearse procedures for managing aircraft approaching the ship. Aircraft handlers have been practising their role using full-size dummy F-35 models aircraft at RNAS Culdrose. These and every other possible preparation has been conducted on both the naval and aviation sides ahead of the real thing, using a variety of simulations and synthetic training aids.

Land-based development testing

The first fixed-wing aircraft to land on HMS Queen Elizabeth will be from the Joint Strike Fighter (JSF) Integrated Test Force (ITF) based at the US Navy’s Paxutent River flight test centre in Maryland. Development of the Short Take Off and Vertical Landing (STVOL) aspects of the F-35B has utilised the specialised Centerfield STOVL facility at Pax River which includes a Ski Jump, a grated Hover Pit and an AM-2 Expeditionary Airfield (used by the USMC to create austere landing strips). Three British pilots are assigned to the ITF and have been preparing for the QEC FOCT for the last four years. A programme of successful ski-ramp launches has been conducted, including in substantial crosswinds and carrying full asymmetric loads. Results from the land-based test programme have reduced the risks and will speed up the ship-board testing process.

Work undertaken by the ITF is about defining the F-35’s handling qualities and the safe operating envelope. This is quite separate from the three aircraft of the RAF’s 17(R) Squadron Operational Evaluation Unit (OEU) based at Edwards AFB. They are part of the international F-35 Joint Operational Test Team (JOTT) focussed on weapons, combat tactics and operational considerations.

The ski ramp at Pax River, built in 2009 is a replica of the 45m, 12º Invincible class ramp. The ramp fitted to the QEC is slightly different, angled at 12.5º and 60m in length.

Big decks, fast jets (at last)

The first jets to land on the ship will be conducting Development Testing in two 3-4 week phases (DT-1 and DT-2), with a break from the intense flying schedule in the middle. Four pilots will be assigned to fly two “orange-wired” F-35B ITF aircraft for the FOCT programme. These test aircraft are technically US-owned jets but the pilots will be British. During the trials, both aircraft will send data for analysis to QE which will be temporarily fitted with a telemetry system. Initial flying will be conducted in very benign conditions but as the trials progress, the ship can seek more challenging weather as she cruises up or down the Eastern seaboard of the US. Simulator models can only be trusted to a point so the programme must proceed with caution, starting at the safest centre of the flight envelope and moving outward. There are multiple test points to be worked through with variables such as wind conditions, sea state and aircraft loading.

DT-1 will involve the pilots getting acquainted with the ship and carrier qualified. Initially daytime, dry deck vertical landings and ski-jump take-offs will be tested, then moving on to night flying and wet deck conditions. For vertical landings, the pilots are assisted by advice from the LSO and visual cues from the Glideslope and long-range line-up indicator system (GILS). Two Advanced Stabilised Glide Slope Indicators (ASGSI) project a vertically colour-coded beam which can be seen between 2 – 5nm away by the pilot, depending on conditions. There are also mountings for the Hihat system on the port quarter of the forward island designed to help the pilot gauge height over the deck when in the hover. However perhaps due to the inherent automation of the F-35, it appears that the Hihat lighting system will not now be fitted to the QEC.

The ASGSI installed on the port catwalk of QE (shielded to protect it from the effects of jet blast). It projects a beam of light, with coloured sectors, stabilised to remove the effects of the ship’s roll and pitch, indicating to the pilot if his approach is above, below or on the correct glide path.

Vertical landing at sea is now routine for USMC F-35Bs operating from their LHD/LHA assault ships. The automation of the F-35B’s flight controls make vertical landing a relatively simple affair compared to the very demanding workload placed on a Harrier pilot. As the QEC have a much larger flight deck and suffer less wind turbulence (because the island is further away from the landing spot), very little presumed risk is attached to this phase of flight testing.

Assuming the first phase goes well, DT-2 will involve more challenging sea states and the aircraft carrying dummy stores in various configurations. The Shipborne Rolling Vertical Landing (SRVL) technique will also be tried for the first time. This allows the aircraft to return to the ship at heavier weights carrying unused munitions or fuel. SRVL also reduces wear on the lift fan and heat impacts on the flight deck compared with vertical landing. SRVL requires flying a very precise approach profile with the aircraft touching down with around 60 Knots of forward speed so the wings are still generating part of the lift. Land too fast and the aircraft will run out of flight deck and have to take off again using precious fuel. Approach too slowly and the aircraft will descend too quickly, potentially hitting the stern of the ship or crashing on deck. This battle with the laws of physics has been managed successfully many times in the simulator but there are still some unknowns about performing this procedure on a moving deck at sea, which has important operational implications for carrier strike capability.

This year’s FOCT programme will define the safe operating clearances for the F-35 but a third development testing period (DT-3) is planned for mid-2019, as HMS Queen Elizabeth moves closer towards her first operational deployment in 2021. We will examine the other non-aviation aspects of the Westlant 18 deployment in another article to follow next month.