Flying Techniques: Aerobatics in the Pitts
PUBLISHED: 12:16 11 December 2015 | UPDATED: 12:16 11 December 2015
KEITH WILSON (C) SINGLE USE PILOT MAG ONLY
Sweating freely and feeling the leaden grasp of 'g' pulling at my face and limbs, I'm not at all sure if I am getting this right. The ground is filling the view forward and I'm holding in left aileron and hauling perhaps a bit too hard on the stick in the hope that Rutland Water is going to come tilting into view… and then, as the nose comes up, there it is: our aiming point, and pretty much dead ahead. I've done it I have actually flown a halfway decent barrel roll! Good grief; perhaps I really can do this aerobatic thing after all. These impressions come halfway
through an aerobatics lesson with Charlie Kimbell, one of the small team of specialists instructing on Pitts S-2A G-BTUL, based at Leicester Aero Club. Charlie and partners David Shutter and Iain Thompson− all experienced competition pilots− are on a mission, they say “to provide a more structured and standardised path for aerobatic training from ab initio right through to advanced competition”. Having flown enough basic aerobatic manoeuvres over the years−loops, stall turns, aileron rolls and even a barrel roll (memorable for all the wrong reasons)−I know that I rather enjoy seeing the world upside down. I am also aware that I have just the right combination of enthusiasm, boldness and inexperience to make a complete Horlicks of it. Thus, in the collective wisdom of photographer and ringmaster Keith Wilson, David and co-conspirator Charlie, I would be the ideal student for a trial lesson. Ideal, that is, in every respect but one I can only now own up to: the Pitts Special had always intimidated me. For years the little biplane has been a kind of aeronautical elephant in the room−a flying challenge to which I should have risen, but one that worried me enough for me always to have an excuse to avoid it. But there’s no getting out of it, now I am sat in the clubhouse at Leicester Airport. “Wouldn’t other types like the tricycle undercarriage Alpha 160 or an easy taildragger like the Citabria perhaps be better basic aerobatics trainers,” I ask Charlie during the preflight briefing. “I mean, with the Pitts don’t you end up spending an inordinate amount of time simply converting the studentonto type?” “Well most Cub pilots pick it up in an hour or two,” he replies with only the slightest hint of raised eyebrows, “but, perhaps not knowing what to expect, people who are used only to tricycle aircraft don’t take that much longer: it’s certainly doable within the usual five-hour course− and the Pitts remains one of the most capable aerobatic machines around.” “Are we going to do any Lomcevaks” I ask (subtext: Am I going to feel sick or… er, need a change of underpants?). “No,” says Charlie “we tend to avoid gyroscopic tumbling in the S-2A in the interests of preserving the engine−gyroscopic precession puts a lot of load on the crankshaft from the metal prop”. “Nor are we going to do any spins on this flight: the S-2A recovers in standard fashion from all spinning manoeuvres. Just following the Müller technique− simply releasing the stick and applying opposite rudder−works in almost all circumstances.” What Charlie is actually proposing is a ‘taster’ for the advanced handling course−steep turns, stalls, stalling in a steep turn and incipient spin recovery−followed by a set of basic aerobatic figures that he will demonstrate and I will then emulate. Hey; this sounds like it’s going to be fun. “And then you can try a takeoff and landing,” he adds. Inwardly, I hear the elephant snort. Charlie looks at me and just grins, his eyes sparkling.
No going back
Even in two-seat form, the Pitts is a small aircraft. As you get closer, it gets smaller still, a stubby fuselage sprouting model aeroplane-size wings. Are we going to fly in this toy – and is 6ft 1in and 100kg-plus of Whiteman going to be able to get in without breaking some delicate part of it? Come on, man: get a grip… Once you have placed your right foot on the seat cushion, climbing into the front seat of the Pitts is more like descending into a cellar through a manhole. Heel slides take your feet to the rudder pedals, and as bottom makes contact with the seat cushion it is the closeness of the panel and height of the cockpit sides that are immediately and unsettlingly apparent. This is not a cockpit for those with claustrophobia and nor is it a place of great physical comfort, as the second impression is that the seat back is shaped and angled to as if it were designed with the sole purpose of giving you backache. “Is it just me…” I ask Charlie, who confirms the torture is suffered universally. “It’ll feel better when the fuselage is in the flying attitude.” The Hooker harness, or rather harnesses (the lap belts are duplicated) requires more attention then the usual non- aerobatic type. For a start there is a crotch strap, designed to better locate the release latch and prevent one from ‘submarining’ under the lap belts in a big smash, and then there’s the ratchet tensioner for the second lap belt. This functions just like those you see around the base of a curtain-side truck. Having been turned upside down in an aeroplane before, I do this up nice and tight. While we wait for the photo ship to be fired up, there’s plenty of time to scan the rest of the sparsely furnished front cockpit. I have a throttle, propeller control, stick and rudder pedals, the absolutely basic flight instruments: ASI, altimeter and turn & slip… and that’s about it. Peering into the gloom, I see that I am sharing the space with the exposed undercarriage bungees and, suspended ahead of the panel and just above my knees, the main fuel tank−something that would be even more disconcerting if it were not familiar from the Cub. Another familiar sensation is back-seater Charlie’s toes occasionally jabbing me in the admittedly over-wide backside, which is either reassuringly Cub-like or mildly disturbing, depending on where you are coming from. The torture of the seating position and possibly over-tightened Hooker harness are just becoming unbearable when David and Keith signal they are ready to start up. Charlie follows suit and the relief and excitement that we are at last getting away banish any further thoughts about physical discomfort. When we reach the runway, I follow through on the controls as Charlie flies the takeoff. As per his briefing, he raises the tail early in the ground run−both to get a better view forward and stop the aircraft leaping off the ground prematurely. (I am told that on grass it is better to leave the stick neutral and allow the aircraft to fly off in the three-point attitude.) While the acceleration and rapidity with which it becomes airborne are highly impressive, I soon discover that once it’s off the ground the Pitts is not so very different in its general handling−at least in the climb and while making the usual course corrections and gentle turns. The stick, which had seemed so short on the ground, offers just the right balance of weighting and movement. The control forces are of course lighter than an Auster’s or a Cub’s, but pleasantly so−and there’s no feeling of twitchiness or over-sensitivity. Rather, you tune in so quickly that you are hardly aware of it−other than thinking it would be nice if more aeroplanes handled like this. I’ve said this before, but it’s a bit like the contrast between a Caterham Seven and an ordinary hatchback car. Charlie flies formation on Leicester’s Cessna 172 for Keith’s air-to-air photography. For the most part, from my position in the front seat the view of the camera ship is obscured (although it is a surprise later to see from the photos how low down I seemed to be sat−it really didn’t feel like that!)
Upside down for the camera
Charlie of course makes a masterly job of it and we soon come to the photo session’s finale, which involves him rolling us inverted for the Cessna to formate on the upside-down Pitts. I’ve experienced this once before on a Pilot assignment, when photographer Mike Vines had the Royal Jordanian Falcons’ Extra 300 in which I was passenger drone along inverted for minutes on end. This was not an enjoyable experience: sixty seconds in, hanging from the straps I’d developed an irrational fear that I was going to slide straight out of my seat through the canopy. Sustained inverted flight is no less horrible today−and Charlie agrees: “Quite how anybody flies the Channel inverted I do not know”. With the pictures in the bag, we head off alone to work through some of the basic manoeuvres and aerobatic figures Charlie has briefed me on. We start with eighty degree banked turns, which require full power and make use of the lines of rivets either side of the top of the cowling as sighting points to set on the horizon. Next come stalls from level flight. Here the Pitts’s behaviour is more benign than many low-wing LSAs and even some high-wingers: it just breaks and mushes down like… well; a Cub. The same applies with the aggravated stall in a left-hand turn−just like Mr Piper’s rag and tube machine, the little biplane rolls neatly back into level flight. Ah, but when Charlie demonstrates what happens when one tries the same thing while turning right, the world is turned on its head as we roll almost inverted. This reminds me of the spin entry of a Cessna 152, although of course we are not auto rotating and recovery is a simple matter of releasing the back-pressure on the stick and applying aileron to roll wings level.
So far, I’ve been flying non-aerobatic stuff but now we are going to do some aileron rolls. “You start by pitching up by twenty degrees, then you unload… and apply full aileron,” says Charlie. My first effort isn’t bad, but I fail to move the stick all the way−a common mistake made by beginners, apparently. Shoving the thing hard over produces a gratifyingly rapid roll that I nevertheless manage to arrest wings-level... or at least something close to it. “Nicely done,” comes encouragement from the back seat. I am really beginning to enjoy this! Next up is the barrel roll−one thing that I know I can balls up, having given a truly shambolic impression of flying one when flying with No 6 FTS at Cranwell last year (my apologies again, Lt Cdr Jones!). Today, Charlie demonstrates how one picks a point on the horizon and offsets it 45 degrees to one side in the intended direction of roll, before winding up to 140mph and simultaneously pulling back on the stick and applying aileron. “Ease the back pressure as you reach the inverted position,” he provides a commentary as he flies the figure, “and then pull again as the nose drops through the horizon”. Needless to say, he ends up with the distant reference marker absolutely bang on the nose. Feeling that there may be too many things to get right and compensating with furious concentration, I try my own hand: the swirling entry seems to be about right, I remember to ease the pressure going over the top and then perhaps pull rather hard as the ground fills the view forward… and then, as the nose comes up, there is the aiming point! It’s Rutland Water and its wide expense allows a much bigger margin of error than the single building Charlie had used in his demonstration but it is in front of us! Perhaps I really can do this after all. Next in sequence, rather surprisingly, comes a loop (I had expected we’d start with one of these). Charlie demonstrates how the back pressure is eased as we go over the top to make sure the figure does not tighten in radius and go egg shaped, a touch of right rudder countering the effect of the propwash. I follow suite and he again compliments me on my effort. By this point we have worked through all the manoeuvres briefed beforehand, but as I am making a fair fist of what we’ve done so far and am actually rather enjoying myself, Charlie continues the lesson with something slightly more demanding; a quarter clover. This is simply five-eigths of a loop followed by a half barrel roll, emerging on a heading ninety degrees to the entry. It takes a bit more concentration and proves very rewarding to fly. “Want to try something else?” “Yes please!” The next figure is something I have heard of but never quite understood: a humpty-bump. This involves pulling to the vertical−looking out to the side and the wire sight-frame attached to the port interplane strut to make sure we are going straight up−counting three seconds and pulling just hard enough to float the aeroplane over what is effectively the top half of a tight loop. Then it is stick forward and glance sideways at the frame to establish a vertical down line, a quick half-roll and pull to recover to level flight. My first effort lacks finesse−I pull the nose over the top of the manoeuvre, rather than float it through, and then forget to look sideways, spoiling the vertical line. These errors are pointed out by Charlie, and a rather more determined second attempt wins his approval; “nicely done,” comes the voice over the intercom. We’ve time for one last bonus: a four-point roll on a parabola. This involves setting the aircraft on a parabolic path, just as we’d done for the basic aileron roll. However, this time the pitch-up is thirty degrees or so, and one has to apply a little bit of ‘top rudder’ at the points where the wings are vertical to prevent to nose from dropping unduly. The challenge is to stop the roll accurately at those four points. Charlie demonstrates and then I have a go. Remembering to unload the stick after pitching up and to use full aileron, I find to my surprise that it’s not as difficult as I’d imagined: the Pitts responds so quickly to stick movements that it is easy to stop the rotation where one wants to. In comparison to the typical touring aeroplane, there’s no telegraphing an intention to the machine, anticipating a lag in the response−here, it almost feels like you are thinking the aeroplane into position (at least at the speed of my thoughts). However, we are now bingo on fuel and it’s time to return to base.
Now you’ve got to land the thing
Back at Leicester, Charlie keeps his patter going as he directs me round the circuit. The speeds are far higher than I am used to with the Cub, but the picture−in terms of sight angles and descent path−looks much the same. Taking control for the landing, he sideslips to allow a better view of the runway−familiar technique, once again−but as we round out, from my position in the coal hole most of the view of the runway disappears. Hmm. As we come to a halt, Charlie asks; “How you feeling – shall we go in, or do you want to have a go at landing it yourself?” I can see bugger all, we are using Leicester’s narrow Runway 22 and the strong wind has an appreciable crosswind element: what could possibly go wrong? “Oh yes,” I reply in what I hope comes across the intercom as a confident tone. We backtrack, which offers a crumb of comfort in that the aeroplane is at least easy to taxi. Then I am lining up and the pulse rate is accelerating. Charlie has briefed me to open the throttle gently and told me that I am going to need to raise the tail to get a view over the nose. In my head, my own instructions to self start running as I push open the throttle: Have those feet ready for the slightest sign of a swing… one, two, three, four – full throttle… tail up… nose swinging a bit to the left: right rudder… Argh, too much – we’re lunging off to the right: left rudder! Now right! And then we are off the ground and climbing. That was the easy bit: now I have got to get the thing back on the ground. As before, the circuit and approach have a familiar aspect−and the Pitts’s elevator feel is just right for maintaining speed accurately. The aeroplane also sideslips very nicely, and everything’s looking hunky dory as the runway blooms ahead. Relax the aileron and rudder pressure… and the view disappears. “Use your peripheral vision,” urges Charlie. “That’s good… hold off now…” Raising the nose to the point that my reference marker−the bottom of the screen−sits on the horizon, I am keeping straight and Charlie, the human radar altimeter in the back, is filling in the missing part of the picture as I feel for the ground. Suddenly we are down: Keep those feet alive… a little jab left… another right… whoops – diverging a little… Brakes! Brakes! And then we are down to a fast canter and not that far off the centreline. Good grief – I did it! “Well done,” comes confirmation from behind. Yes; I’ve had some superb coaching, and of course an expert eye on me throughout,
but it is possible after all. Goodbye, dear elephant and hello Pitts flying: What a machine! This has been an eye-opening experience: I want another go!