Like a Red Arrow: Folland Gnat Flight Test
PUBLISHED: 10:42 06 October 2017 | UPDATED: 15:26 01 November 2017
Motoring journalist, RV builder and pilot Colin Goodwin relishes the chance to fly the Folland Gnat, former RAF trainer and first Red Arrows’ mount.
When I first started as a motoring journalist decades ago there were many sleepless nights brought on by the excitement and anticipation of driving a new high- performance car. A Ferrari on Monday meant little sleep Sunday night. Today there is still a buzz, but not the debilitating sense of excitement−not least because these days there is rarely the thrill of the unknown, except for ultra high performance hybrid cars which offer a different sort of performance at a different level.
But last night, so Mrs Goodwin reported this morning, there was a lot of wriggling and movement. Perhaps in my subconscious I was trying to get into a G-suit.
I grew up knowing all about the Folland Gnat, as it entered service only three years before I did. It was of course the Red Arrows’ mount before the Hawk entered service in 1979. For a budding RAF pilot in the ’60s and ’70s it would have been your port of call after the Jet Provost and before the Lightning, Phantom or other front-line fast jets.
I have never flown in anything like this aeroplane and my only first-hand experience of jet propulsion in such a direct sense was when I drove the Vampire jet car in which Richard Hammond made his first and most famous attempt on his own life. The acceleration was vivid and I’m expecting similar from the power to weight ratio of the 4,520 lb thrust Rolls-Royce Orpheus turbojet and the 9,520 lb MTOW (max takeoff weight) Gnat.
It’s very tight in the back of the Gnat − almost claustrophobic. The whole aircraft is tiny, with a wingspan that at 24ft is a foot narrower than my RV-7’s. It feels tight and I can see why my pilot Edwin Brenninkmeyer, who is 6ft 5in, is restricted to the front cockpit.
He has given me a very thorough briefing about the procedure for ejecting from the Gnat that included the advice to keep elbows in on the way out. (I learn afterwards that Brenninkmeyer was measured up before joining the team and underwent a ‘seat-pull’, being hoisted from the aircraft, complete with seat and equipment, effectively replicating the full ejection path from the cockpit to ensure safe ejection.)
More important instructions: I must not touch anything in the cockpit except the joystick and throttle because it is extremely easy to disable some of the front cockpit’s controls, which would mean that Brenninkmeyer might end up in the horrendous situation in which he’d have to sit there helpless while Goodwin did the landing. In this instance I feel he would be well advised to eject!
We’re at North Weald at the home of the Heritage Aviation Trust. Heritage Aviation is on the lookout for new trustees (more of which later) and very kindly offered this extremely excited 54-year-old a ride in a Gnat.
Edwin Brenninkmeyer instils a lot of confidence, which you need when you’re being flown in a high performance machine that can easily bite the foolhardy and incautious. His briefing, a lot of which is about vacating the premises via Folland’s own ejection seat (which is surprising as you’d expect the Martin-Baker route to have been cheaper and simpler for the company rather than develop its own system), is clear and precise. He reminds me of Richard Grace (of Grace Spitfire fame) who is also a master at setting the mind at rest. Like Grace, Brenninkmeyer has been flying all his life and has a CV that is most reassuring, including display flying with the Tiger Club−which for me is a pretty suitable testimonial.
If you like dressing up you’ll love this world of fast jets. First of all there’s the drab green RAF-issue overalls with their trademark map pockets on the knees; then a pair of heavy boots. I’ve always wondered why RAF pilots wear footwear that looks designed for stevedores but it’s apparently to protect the feet in an ejection and for walking across inhospitable terrain afterwards. Then there’s the G-suit which is actually like an inflatable pair of cowboy’s chaps and, topping it off, a Top Gun-style helmet. Oh, and RAF Cape leather gloves which should never be worn when flying any Cessna or Piper.
Suited and booted, it’s out to the little jet. It’s so low to the ground that no ladder is needed. A foothold folds out and then it’s a matter of grabbing the wing’s leading edge, the cockpit surround with the other hand, and hoiking yourself up.
As previously mentioned it’s tight in the back of a Gnat. I slip my feet in and thunk down into the seat on top of several painfully sharp buckles. You need help from the ground crew for what comes next. Not only does the harness have to be done up, but the G-suit’s air supply must be connected and also the air supply to the mouthpiece that’s part of the helmet assembly and which contains the microphone.
Then there’s more ejection seat briefing and a reminder of how to manually separate yourself from the seat if it doesn’t happen automatically, which it should, and how to manually deploy the parachute if it doesn’t happen automatically. Which it had bloody better do!
I am now reasonably comfortable, strapped in tight and connected to the aircraft via several tubes. The narrowness of the cockpit makes you feel part of the aircraft, being plumbed into it increases that feeling. Now for a look around the environment: between the back of Brenninkmeyer’s head and me is a Perspex barrier or dummy screen and below that is the instrument panel.
It has a very military look but I wouldn’t call it particularly well laid out. Many of the gauges I’ve never seen in any aircraft I’ve flown−like a Mach meter (which reads to Mach 1.2), exhaust temperature and percentage rpm. Most of the other instruments are familiar such as a VSI, altimeter, ASI and fuel contents. The latter reads up to 20 and that isn’t gallons−it’s two thousand pounds of Jet A1. We will use up a large chunk of it in our forty-minute or so flight.
There’s another gauge on the panel that I haven’t mentioned and that one gives you the position of the tailplane. The Gnat has an all-flying tail like the Piper PA-28. It’s hydraulically operated (there’s a pressure gauge for the hydraulic system). Edwin gave me a very thorough description of what happens when the trim system packs up but it’s so complicated that I didn’t really understand much of it.
Basically you have to fly the aircraft on a small trim tab−but even that isn’t as straightforward as it sounds. (By chance I bumped into an ex-Gnat pilot just a few days after flying this one and the first thing he mentioned is the trimming system. “It failed on me once and I couldn’t stop the thing climbing. Had to go inverted to stop it going to the moon.” Right.)
You start the Gnat’s Orpheus engine by compressed air supplied by a device called a Palouste. It’s a gas turbine that was used to start many jets of the period, including the Buccaneer. Apart from the baby in the seat in front of me on a recent flight home from Italy, I have never come across anything so small that can make so much noise.
Brenninkmeyer gives a thorough and fascinating commentary over the intercom. He hits the igniters as compressed air spools up the engine and the engine is lit. So smooth, with a very tolerable whine that I’m sure is a lot noisier to ears outside the aircraft. Brenninkmeyer taxies slowly and carefully to North Weald’s runway, paranoid about a stone or other FOD being sucked up into the Orpheus.
As chief engineer Peter Walker tells me later, it will be a lack of engines that will eventually ground the Gnats. From where I’m sitting the aircraft seems to be very manoeuvrable on the ground, helped naturally by its compact size.
This is it then. Lined up and ready to go and I’m beyond excited. The acceleration is far from extreme (a big-engined Extra feels faster off the mark) but is very linear and doesn’t tail off. Wheels up and the bottom of Stansted’s controlled airspace is 1,500ft above us.
We’re heading out east towards the coast north of Felixstowe purring along at 250kt. This is our speed limit if we are not on someone’s radar screen. Wattisham’s radar is up the spout today so we’re going to call up Southend and as soon as that’s done the man in front can pour on more gravy.
This low there is a speed sensation. It’s not otherworldly as we’re only going about eighty knots faster than my RV’s full-chat speed−for now. “You have a go,” says Brenninkmeyer from the front. The throttle is on the left side of the cockpit so I’m forced to use my right hand on the stick, which is the opposite to what I’m used to.
I can’t do a swap anyway because the handgrip is contoured for a right hand. Brenninkmeyer told me that the Gnat reacts quickly to control inputs, has a very fast roll rate and that gentle control inputs are the ideal. With this in mind I take a light hold of the stick. Our main concern is that at 250kt I don’t spear us up into controlled airspace.
I’d set the altimeter before we took off but the easiest instrument to read is the VSI so I keep an eye on that to make sure I’m not putting the Lilliput jet into a climb. Actually, it’s not twitchy in pitch at all−less so than the RV. And it isn’t nervous in roll either, but it does gently roll a few degrees from side to side. After a few moments it’s clear that the best approach is to let it self-correct rather than try and cancel it out with the ailerons.
We’re in contact with Southend now which means I can nudge the throttle forward. “Try about eighty per cent,” says Brenninkmeyer. Far from the delay I was expecting, the Gnat immediately surges forward and in a remarkably short time the ASI is reading 350kt. Now we really are clipping along and I suspect that there is a massive grin on my face, uncomfortable oxygen mask permitting.
With this extra airspeed the Gnat has stopped rolling from side to side and is now completely stable. We’re warned of a Cessna out to our left (and he’s warned ‘Gnat at your nine o’clock, fast moving’) but he’s passed in a flash.
We’re now at the coast north of Felixstowe and south of Sizewell. There’s a temporary purple airway to our north so we have limited space for Brenninkmeyer to do a few aeros. He starts with a couple of twinkle rolls. You’re obliged to pause between each roll in the Gnat because a string of them risks inertia coupling causing control difficuties.
“It rolls quickly,” he says, “so be ready.” It does too−about 360 degrees per second. Not as mad as an Sbach but very brisk. My turn. Lift the nose but nowhere near the ‘ankles on the horizon’ that the RV requires, and bang. Beautiful!
Brenninkmeyer explains to me that the Gnat, due to its swept back wings, doesn’t stall like a conventional aircraft and has a wide buffet margin. As the angle of attack increases you get a mush with a massive sink rate. A loop, as he demonstrates, is flown at the ‘nibble’−the onset of buffet. We haven’t got a high enough cloudbase for me to try one but the man in front does a lovely, tidy one. Anyway, if I haven’t done quite a lot of aerobatics within the last few days−and I’ve not−I start to feel sick very quickly. And the Gnat’s cockpit would be very difficult to clean...
We turn the jet back towards North Weald and again I take over. It’s so smooth through the air, no vibration at all and hardly any noise. So different from being in a big piston-engined machine. In a Spitfire you have the constant hammering and vibration from the Merlin, lovely as it is, to give you the feeling that you are being punched through the air.
The Gnat’s smoothness and tranquillity gives the impression that the air has given up trying to drag us back and is letting us slice our way through.
Within a very short time the North Weald circuit is on our nose. Brenninkmeyer will demonstrate the classic ‘run and break’ to knock our speed down to more suitable numbers for downwind and final approach. They’re still big numbers. Depending on weight, the over-the-hedge speed varies between 130 and 145kt.
Those figures seem scary but in reality when our man brings us in it’s a non-event. From my restricted-view perch in the back I can see that he flies us onto the runway rather than floats us onto it. We’re really cracking along and I can feel that Brenninkmeyer is doing a lot of taildragger-style work with his feet to keep the Gnat straight and true. Looking at the ridiculously narrow 5ft 1in undercarriage I’d suspected that some concentration would be required. The brakes are incredibly effective and in short order we are taxying off the runway.
All of this has been an extremely undisappointing experience. So different from anything else that I’ve been in or taken control of. I’d imagine that flying in formation with another Gnat and then aerobatting in company with it would be the ultimate buzz. There is another Gnat in the trust, the yellow machine once owned by Pink Floyd’s David Gilmour, but Brenninkmeyer’s eyes really sparkle when he talks about the single-seat fighter version that they’re readying for the air.
It’s lighter than the trainer and should be even more exciting. You can see the gas extraction ports in the engine intakes where the original cannons were fitted.
The Heritage Aircraft Trust operates the Gnats via a limited company. The group is on the lookout for a couple more trustee-pilots. Clearly, running and maintaining the jets is hugely expensive so the numbers are big.
A new trustee has to bring with him or her £75,000 which will be put into the trust. It’s not a share, so once it’s handed over that’s it. Then there’s a monthly fee of £2,500 to cover hangarage, maintenance and all other standing costs including engineer Peter Walker, who is the most experienced (he’s ex-RAF) Gnat engineer in the world, and a couple of apprentices.
Large sums of money, but as I point out to Brenninkmeyer, not so outrageous when compared to other extreme adrenaline hobbies. Running a classic Formula One car for example. A friend who does just this in historic racing reckons that a European meeting will cost him around £15,000 for the weekend and that a full rebuild for a Cosworth DFV is around £100,000.
In that context, the cost of putting yourself into the Gnat isn’t any more extreme. Each sortie costs around £1,000 in Jet A1 which wouldn’t buy you a set of slicks for your old F1 car. Anyway, it’s somewhat pointless talking about pound notes because most of us are not in this league and have enough trouble putting a few litres of 100LL in our machines and paying for the hangarage.
But there are others for whom cash isn’t an issue and for them the Gnat will provide a thrilling experience. If there is a distant aunt who I don’t know about but who is about to leave me millions, I will for sure be writing Mr Brenninkmeyer and his fellow trustees a fat cheque.
A blast in a Gnat once a fortnight would contrast nicely with flights in my Hawker Sea Fury.