Going back to the RAeS article SpazSinbad linked to:
UK F-35B - on final approach to QEC
In just over a year's time, one lucky UK test pilot is set to perform a historic flight - the first landing of a new fighter aircraft on a brand-new aircraft carrier - a double first that is a major milestone. "This is the SuperBowl of flight test - a once in a lifetime opportunity," enthuses RAF F-35B test pilot Squadron Leader Andy Edgell.
The majestic entrance of HMS Queen Elizabeth into Portsmouth earlier this week and the pride and excitement surrounding it, is an indicator of the importance that the first F-35B landing on the carrier will carry.
Indeed, while next year it will be eight years since the retirement of the iconic Harrier, you have to go back over 50 years to 1963 when Hawker test pilot Bill Bedford made the first jet fighter vertical landing on an aircraft carrier on HMS Ark Royal in the P.1127. The rest, as they say, is history with the Harrier, Sea Harrier and AV-8 being adopted for shipborne operations by the UK, USMC, Italy, India, Spain and Thailand.
Fast forward to 2017 and Edgell (UK MoD First of Class Flight Trials (FOCFT) Lead Test Pilot) is one of the UK F-35B test pilots embedded into the JSF Integrated Test Force at the US Navy’s Paxutent River flight test centre in Maryland.
His role in the US, (like his colleagues Cdr Steve Crockatt (RN and Team Leader) Cdr Nath Gray (RN), Sqn Ldr Ben Hullah (RAF) and BAE Systems' own Pete 'Wizzer' Wilson) as a developmental test pilot is to define the edges of the envelope, investigate handling and focus on safety.
Edgell stresses that this developmental testing (higher, faster and, occasional, slowest) is separate from the F-35 work undertaken from the RAF's 17(R) Sqn at Edwards AFB that concentrates on weapon employment, combat tactics and how to use the fighter operationally.
This team (along with UK engineers, maintainers and support personnel from the RN, RAF and industry) have been busy this year conducting the second phase of land-based F-35B ski-jump testing at Pax River - a critical stage in proving that the F-35B is ready to go to sea in 2018. Over 70% of the ski-jumps needed have now been completed with the team working on the toughest challenges, such as maximum stores asymmetry and crosswinds (One drawback of the land-based ski jump testing at Pax River is that the team have to wait for the wind conditions to co-operate for the correct speed and direction.)
These pilots are also tasked with developing and de-risking the new Shipborne Rolling Vertical Landing (SRVL) technique which will allow higher bring-back of stores in hot climates than the traditional hover. This uses a straight-in approach with the aircraft slowing from about 140kt to approximately 60kt over the carrier’s stern - with the aircraft still getting some aerodynamic lift from the wings. As well as allowing higher bring-back weights, SRVL also has side benefits, such as reduced wear and tear on the LiftFan and less damage on the same landing deck 'spot' from the powerful rear-nozzle exhaust.
While some critics worry that it could be more workload-intensive in bad weather or a fouled deck, others describe it as a 'doddle' in the sim. One F-35B pilot is sanguine about the technique, pointing out that a short, slow landing is nothing new for land-based Harriers and observes: "In fact, if we were still operating Harriers now, we'd probably be using it". It will thus be for Edgell, Wizzer and the rest of the team to prove this concept at sea.
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Supporting the UK developmental flight test team at Pax River is BAE Systems, where some 50+ years of Harrier experience is being brought together to make the F-35B the easiest and safest VTOL fighter ever to operate from a ship. Just opened earlier in March, BAE Systems F-35/QEC simulation facility at Warton, Lancashire is a key part in testing and de-risking fixed wing naval operations. Simulation and modelling is highly critical for QE and F-35B, not just because of the increased fidelity and processing power available but also with the UK having been out of the fixed-wing carrier game for seven years - nothing and no detail too small is being taken for granted. For example, CFD modelling of wind interaction around the distinctive twin islands is incorporated in the simulator.
The most challenging area to model, notes BAE's David Atkinson in charge of the new facility, is in the F-35Bs transition phase between conventional wing-borne and vertical flight.
BAE says that the £2m facility, which includes a moving platform F-35 cockpit, dome visual system and a simulated QEC FLYCO (Flying Control), is its most sophisticated flight simulator yet. It uses 64 processors and 1TB RAM and allows test pilots to practice, train and rehearse safely before they even get to the ship. The inclusion of a FLYCO in the room next door also allows Royal Navy LSO (Landing Signal Officers) to experience, train and develop CONOPS in controlling F-35B launch and recovery operations. Cameras give a gyro-stabilised view of pilots’ approach with gradient and centreline guides marked. BAE is also trialling video gaming virtual reality headsets to allow LSOs to immerse themselves in a virtual FLYCO and see exactly what they would see onboard the real ship.
So, what is the value of this facility to highly experienced test pilots, some of whom have already taken the F-35B to sea, albeit on US Navy assault ships? Says Sqn Ldr Edgell: “As testers you are inherently cynical. However good the modelling is, we have to do it for real. However, it builds confidence and tells where we need to focus our efforts. It also potentially allows us to take bigger steps towards the edge of the envelope.”
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So, what is the F-35B like to fly? Thanks to the pioneering work of UK's DERA (now DSTL/QinetiQ) VAAC Harrier testbeds and test pilots like Justin Paines and John Farley in developing advanced FBW software for VTOL aircraft – it is extremely simple. Whereas the Jedi-like skills are needed to control the Harrier in the hover requires movement of throttle, nozzle control and stick and has been likened to 'balancing on the top of a pencil while needing three hands', the F-35B’s fly-by-wire controls are just a sidestick and throttle HOTAS - with the flight computers doing all the hard work. (It is noteworthy that the UK is the only country after the US to have its own lines of code in in the F-35 software).
To assist pilots coming into land, there are two velocity vectors - a traditional one, and a ship-shaped one - showing where the ship will be. The ship’s speed is also entered into the flight management computer via the touchscreen display.
Approaching the ship from behind at around 170kt and 500ft, once at 200ft the pilot hits the 'brake' deceleration button and the aircraft begins slowing and transitioning to a hover, with the LiftFan engaging and the rear nozzle swivelling down for vertical flight. Once slowed down, the pilot can swing to the left side of the ship. The aircraft's flight computers now cleverly match the ship's speed, with the pilot pushing forward on the control sidestick (or inceptor) to go down. At 100ft and about a wingspan across from the deck, the pilot is thus ready to transition sideways over the deck, with fine hovering control being provided by the moving rear nozzle, LiftFan and the STOVL roll jets at the tips of the wings. At this point, with the flight controls engaged and the aircraft happily matching speed with the ship, the pilot can even take his (or her) hands off the controls - a move that would most likely be suicidal in the Harrier for the average squadron pilot.
Hitting another thumb switch on the HOTAS throttle engages a translational controller mode, enabling the pilot to slide across in the hover and line up with the centreline. Once in position – it is a case of pushing forward on the sidestick to a software-controlled stop to descend and put the aircraft firmly on the deck. At this point, control of the engine thrust and vertical motion has passed to the right hand, rather than the left hand - which on the first occasion is slightly disconcerting to push full forward on what is normally a pitch control, some 50ft above a deck.
Those raised on Call of Duty Xbox controllers will have no problems. Feet on the brakes and the aircraft lands itself. Effectively with these flight controls you are flying an aeroplane that cannot stall and where intuitive pull back/go up and push forward/go down still work - even when hovering. Says BAE: "The control philosophy is such that the left-hand commands go-faster / go-slower whilst the right-hand commands the aircraft to go-up / go-down and go-left / go-right. Each hand commands a response in the same axis in both wing-borne and jet-borne flight." It is not quite the 'take me home and land the aircraft automatically coffee bar button' that legendary Harrier test pilot John Farley often joked about as something that a future VTOL fighter would need, but it is close.
Taking off is even simpler. Line up on the centreline for the ramp. Hold feet on brakes - move throttle to detent and then to full and it will take-off, with just rudder pedals used to keep on track. No sidestick control movements are needed - although pilots will guard the control stick with a hand.
Interestingly, for those wondering about the SRVL and stopping a heavy aircraft without an arrestor wire on a short deck, this correspondent found that the carrier’s deck proved remarkably 'sticky' with a fair bit of throttle needed to get the aircraft moving. BAE says the modelling in the simulator includes dry, wet and flooded decks - and it has also carried out friction studies with F-35 tyres and the deck material.
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But it is not just in-flight test and simulation where the UK is deeply involved with F-35. Down the road from Warton at BAE Systems’ factory in Samlesbury is evidence of the huge industrial and supply chain involvement in this programme - with the company machining and building aft fuselages, horizontal and vertical tails for almost every F-35 made. While all eyes were on Portsmouth earlier this week, Wednesday also saw a significant industrial milestone passed for the F-35 - with the 318th rear fuselage section produced at Samlesbury rolled off the production. This represents just 10% of the final global production total.
Inside BAE's Samlesbury facility, a highly automated, cutting-edge facility building and assembling precision components for F-35 the sheer scale of the programme is apparent. After a slow start Samlesbury is now in the middle of production ramp-up, as the F-35 programme goes into high-gear - supplying assembly lines in Fort Worth, Texas, Italy and now Japan. This year it will ship 92 aft fuselages, 78 horizontal tails and 83 vertical tails (other facilities in Australia and Canada building the difference in HT/VT and aft fuselages). This represents a 30% increase in the production rate, with another 30% increase in 2018.
This is just part of the UK's involvement in the gigantic global F-35 programme - which eventually could see over 3,000 aircraft produced. As well as the aft empennage and wingfold for the F-35C carrier variant, BAE provides the EW system, HOTAS (or active inceptors) and vehicle management computer, as well as being the lead design authority for the fuel system, crew escape system and life support, with 1,525 people directly employed by BAE on the F-35. Looking wider, it is estimated that the F-35 will sustain some 25,000 UK jobs in 500 companies when it hits peak production rate in 2020. These range from big names like Rolls-Royce (LiftFan), Martin Baker (ejection seat) MBDA/Raytheon (UK weapons integration) to smaller SMEs.