Flight Test: Scottish Aviation Bulldog
- Credit: Archant
A British classic full of character and a pleasure to fly
Words: Nick Bloom; Photos: Keith Wilson
There aren’t all that many aircraft flying today designed and made in Britain. Some ? the Spitfire and Vulcan, for instance ? have become national icons. The Scottish Aviation Bulldog isn’t quite in that category, but it is a treasured asset from our past.
You can go into almost any of the hundreds of flying clubs dotted around the UK and find some ex-RAF and ex-University Air Squadron pilots who flew Bulldogs in their time. And I expect almost as many civilian pilots have had a go since the RAF sold them off in 2001. There are over fifty Bulldogs listed in G-INFO, a number of which are available for training.
The aircraft continues even now, 46 years after the prototype first flew, to refine piloting skills. Add in the Bulldog’s continuing value as an advanced trainer and it becomes a significant machine indeed.
The prototype Bulldog was constructed in 1969 by Beagle Aircraft, but they ceased trading so manufacture (by then a big order had arrived from Sweden) went to Scottish Aviation, which was subsequently absorbed into British Aerospace. The RAF bought 130 Bulldogs in 1972.
The Bulldog I am to fly, G-ASAL, is one of the earliest examples. It was built in 1973 by British Aerospace ‘for development and demonstration’, which meant it never had a full C of A and currently flies with an LAA Permit. It was the first Bulldog to have one.
Cameraman Keith Wilson and I arrive at Prestwick Flying Club, home to the twenty-member-group operating G-ASAL. We meet Stuart Hill who instructs on the aircraft and will fly with me. Following a briefing, I go out for preflight checks and start-up. Parked on the apron, the Bulldog has a graceful air, with its streamlined shape, closely-cowled engine and tapered wings.
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One instance of the attention paid to streamlining is the trousers fitted to the undercarriage legs. The outer portion of the wing has a drooped leading edge creating under-camber, quite a trick to manufacture in sheet aluminium. I imagine it was added after initial flight testing to produce a more forgiving stall. There are slotted flaps down the inner two-thirds of the wing trailing edge. The outer third has Frise ailerons, which look large enough in this slim, tapered wing to give a good roll rate.
The cabin has a sliding generously proportioned canopy, giving ample room for RAF types in bone domes and parachutes (very bulky in the 1970s). In fact, the cabin dominates the whole aeroplane.
The fin and rudder similarly look outsized, especially with the large fin strake fitted under the rear fuselage. There are more strakes ahead of the relatively modest-in-area tailplane and elevators, usually an indication of concerns about spin recovery in the powers-that-be.
Cockpit-operated trim tabs are fitted to the Bulldog’s fin and elevator. The noseleg looks sturdy and there is a steerable nosewheel, which must have eased the training for students when compared with the taildragger challenges of the Bulldog’s predecessors, the Chipmunk, Miles Magister and Tiger Moth.
Construction is riveted aluminium sheet (no fabric) with plastic for fairings and wingtips, and the control circuits are mostly cable-driven with pushrod final drive.
Some years ago, I worked for a spell as an apprentice aviation engineer and I remember an entire day spent undoing all the inspection panels on a Bulldog. It was uncomfortable work – most were underneath the aeroplane, the screws were hard to remove (many with damaged heads and corroded in place) and the paint underneath the aircraft had seen hard times. However, whenever a panel cover was removed, the view inside was invariably immaculate, as though the aeroplane had just left the factory. I was struck with how solid everything looked, as though strength and longevity were foremost in the designer’s mind and be damned with building light.
Seen close, the Bulldog looks British and military, but step back and its lines appear graceful. G-ASAL has no exterior step and handhold (they were only on earlier models), so I step up onto the wing unaided. I settle into my seat, which is comfortable (if a little far back as the seats are fixed) and admire the controls.
These must be a major factor in the Bulldog’s continuing appeal, for they are utterly different from anything in a Piper or Cessna. The look is sports car and charmingly retro. Instead of push controls and fiddly verniers for engine and propeller control, you get good, solid levers and they are colour-coded and aligned in a row, just like on airliners or bombers.
In place of yokes (introduced, I understand, to allow women to fly without exposing their stocking tops) we have control sticks, and these are beauties, kinked in two places and with a no-nonsense grip. No question of your hand sliding off these joysticks in the heat of battle, aerobatics or flying display. Other similar features include a sizeable, scalloped wheel for elevator trim, a rudder trim control and a flap lever with a nicely ‘vintage’ window indicator.
The grips in G-ASAL are actually fitted with gun triggers and there is an armaments panel still in place on the instrument panel. I haven’t seen one of those on a Bulldog before. The rest of the panel is the usual mixture of old and new, thankfully without much in the way of digital display ? in fact, it’s virtually all good, old-fashioned analogue.
There are several more military touches, notably the guarded push-to-start button. Behind the seat is a large baggage area, increasing the already generous allocation of space. There is a variant of the Bulldog, which accommodated an observer back there and carried a crew of three.
Stuart arrives and initiates me into pedal adjustment in the Bulldog, which is delightfully simple and effective: a catch you hook with your shoe, allowing the other foot to pull or push the pedal on that side. “Make sure both sides have the same setting, or you’ll have an offset rudder,” warns Stuart.
We each do up our military style, five-point harness. Adjusting mine is the usual fiddly business but I get there in the end. Stuart pulls the canopy closed and locks it, going through his instructor’s patter in explaining how it’s unlocked and/or jettisoned in an emergency. We run through the usual checks, prime and start the engine in lean. I push the starter button, having set the throttle, with my other hand ready to push the mixture lever forwards. We wait for the cylinder head temperature to rise, then set off.
Taxying in the Bulldog is utterly easy, with a steerable nosewheel and effective hydraulic disc brakes, plus the superb all-round visibility. This ease of operation is one of (very few) weak points in this design, because you don’t want a military trainer to make things too easy. That way you only give the really expensive hardware to pilots who can hack it.
We get to a holding point and run through more of the usual checks, cycling the VP prop, checking the mags and the slow running and one I’ve not met before, checking the operation of the mixture control. I set first stage flap; full flap is reserved for landing. The Bulldog has exerted its usual fascination.
As soon as we lift off, we are catching up with the cameraship rather faster than I like, so I throttle back and ease back on the stick to slow down. Soon the stall-warner is operating intermittently. “Is the stall-warner accurate?” I ask Stuart. He says (do I hear a gulp?) it is. The one rule of formation flying is to keep the other aircraft in sight, so I don’t want to overtake, but nor do I want to stall at low altitude.
It doesn’t feel as though the Bulldog is about to misbehave, so I ignore the stall-warner and keep going at low speed and part throttle. The Bulldog is a superb formation aircraft. The field of view from that big cockpit, plus two generous rear windows, makes it easy to keep other aircraft in sight.
It’s great to have a power lever, because that makes the constant adjustment to maintain position straightforward. You want small adjustments, and to be able to go from full power to none instantly. The controls are powerful and precise.
In this flight mode (aerobatics come later) the controls are well harmonised. We make increasingly tight orbits with the Bulldog on the outside and on the inside of the turn. Again, it makes it easy ? although on the inside, to maintain position alongside the slower Cessna, the Bulldog’s nose is noticeably higher. When I bank slowly to ninety degrees, using opposite rudder to keep up the nose, the aeroplane sinks dramatically. “It won’t fly on its side at this speed,” says Stuart.
The high wing loading is making itself felt, catching the cameraship unprepared. In contrast, the head-on shot goes perfectly because, even with the controls fully crossed, I can play the aeroplane with the power lever, drawing it steadily closer to the camera. This is where streamlining and, above all, power tells.
However, my right leg is soon quivering, because that big rudder, aerodynamically balanced though it may be, is getting blown by the blast from the propeller and fighting back. Eventually the cameraship heads back to Prestwick, leaving Stuart, the Bulldog and me over the magnificent Ayrshire coast in brilliant sunshine.
What a setting for aerobatics! But I blow it, attempting a loop from cruise speed. Stuart warns, “We loop from 140kt,” but I am keen to experiment. You learn more about an aircraft looping it from minimum speed, and there are few that won’t do it from cruise. Well, the Bulldog is one of them.
We get up and over (pulling 3.5g) without difficulty but, as we hit inverted, the aeroplane sags tiredly and starts to autorotate. We had agreed not to spin the aeroplane without parachutes, so rather than fight it, I go with the flow, allowing the aeroplane to roll upright and stopping the roll with opposite rudder, at which point it stabilises. The price for this is a fifty-degree change of direction and ending up well nose-down and short of speed.
The pullout of the subsequent dive isn’t high-g, but it seems to go on a long time. I hear Stuart grunt a few times. “A high wing loading aeroplane, then,” I say. Dignified silent assent from Stuart. So I do the sensible thing and dive to 140kt, which does indeed produce a perfect loop without the least difficulty. Accelerating to that speed first, though, squanders a fair bit of height. At least with a CS prop there are no worries about over-revving the engine.
The 140kt loop is, to my mind, rather an unpleasant manoeuvre as it lacks finesse and the g-force has to be sustained for so long. I loop my Currie Super Wot at 80-90kt and barely feel the ‘g’. From the display point of view, both the Wot’s tiny, quick and slightly comic loop and the Bulldog’s majestic, graceful, sky-filling alternative have their points. I know which I prefer from inside the aeroplane, though.
But, and it’s a big but, this is an RAF trainer designed to prepare students to fly jets. From that point of view, teaching the necessity to have speed in hand at all times is exactly what’s needed. The control harmony for aerobatics is less than ideal, although typical of many trainers. While aileron forces are low, the elevator firms up considerably at manoeuvering speed. So do rudder control forces.
In an aeroplane purely to help you fly aerobatics, you really want all three controls to be equally light and powerful. Stuart says several times during the sortie, “The Bulldog isn’t really an aerobatic aircraft ? it’s a trainer.” So looping manoeuvres perhaps aren’t the Bulldog’s forté.
How about combined rolling and looping? With assent from Stuart I dive to 130kt to try a half-reverse Cuban. I get a good view forwards and then of the wingtip going up, hit 45-degree climb, hold it there, wait a second, roll inverted and, whereas the Currie Super Wot would have lost nearly all its energy in the half-roll, the Bulldog still has plenty in reserve. So I can hold the inverted climb for another second before gently (relaxing the stick than pulling) easing over the top and then down through a three-quarter loop to complete the manoeuvre.
The pull-out is still a little unpleasant, but I don’t think we lost much height. Including the dive, we probably lost 300ft. Next, I sample the half Cuban, which isn’t quite as nice because with the half-roll on the way down, the aeroplane gathers speed faster still. Once again we lose height, which is becoming something of a theme in this aeroplane.
Incidentally, over the top of the halfreverse Cuban, I was aware of needing a fair bit of rudder ? no bad thing in a trainer. The aircraft is upside-down, slow and short of energy, but it still has upwards momentum to fight gravity. This position is a great teacher, particularly around use of rudder and elevator in an incipient stall. I liked that bit.
I try a barrel roll to the left, the easiest direction with a Lycoming. It goes, but not well, because I use too much rudder, a habit I’ve picked up with the Currie Super Wot. The long-suffering Stuart demonstrates (“Mind if I have a go?”) you barely need rudder to produce a barrel roll in the Bulldog. I notice he pitches up quite high before starting the manoeuvre, which would earn penalties in a competition (pitch and roll should be begun together), but which stops the manoeuvre losing height (as mine did).
Equally effective is the aileron roll I try next. Dive a little (120kt will do), pull up fairly steeply and immediately push the stick all the way to the left, holding the rudder still. I wasn’t timing it, but from memory it took five seconds for us to complete the roll, ending nose down but by no more than we were nose-up at entry.
So now I want to try an axial roll. I pitch up a little (five degrees), stick fully left and feed in a little right rudder, then more as we begin to go inverted, together with some forward stick to keep the nose up. The roll rate is perfect for teaching, slow enough to talk the student through it in sections, but fast enough for the aeroplane not to lose energy. Now we’re hanging in our straps, I’m feeding in more right rudder to offset engine effects, then reducing rudder as we approach the last quarter, finally centring and then reversing rudder. As we head to the finish, I’m pushing more and more left rudder, at first to keep the nose up, and I’m feeding in up-elevator too, then to stop the nose drifting off-axis to the right.
We finish without loss of height and still pointing at the same cloud. It went well, though it felt a bit uncomfortable, particularly rudder forces towards the end. In fact it went so well that with Stuart’s slightly dubious okay, I’m going to try a four-point hesitation roll. This goes extremely well ? surprisingly so, as I don’t cheat on the hesitations, giving each a second or two. Now that’s the manoeuvre I’d want to see at a Bulldog display.
We’re two-up with lots of fuel, and I’ll bet an expert, alone in the aircraft could fly low level four-point rolls ’til the cows come home. Were they to do that, I suspect the turn-around manoeuvre of choice would be a stall turn ? but we haven’t flown one yet, so I make that my next figure. As I suspected with that big fin and rudder, it goes perfectly at first try. I’m guessing this isn’t one of those aeroplanes where timing for the yawaround is critical and you either roll out, ‘bridge’ or tailslide unless you get it absolutely right.
Also, from the display point of view, a pull up and fairly short vertical from low altitude, a lazy reversal via rudder from straight up to straight down from not much higher, and a pull-out back to level near the ground again, particularly in a graceful-looking aeroplane like the Bulldog, is hard to beat. I sample a half-loop, half-roll, but since you have to dive to 145kt before commencing the manoeuvre, it seems fairly pointless from the display or competition point of view. It goes okay, but it does need that entry speed to pull it off without sinking at the top or going off-axis.
As Stuart says, “Not much energy, is there?” I try a level stall ? the Bulldog drops a wing and mushes down, but still under control ? and a turning stall. The turning stall also ends in a mush-down and the wings sort of level themselves. The impression is not so much impending auto-rotation as a heavy machine that’s become tired and wants a lie-down.
Not very appealing, actually. I prefer something with more wing area for low-speed flying. I attempt what I call a loitering turn, the kind of thing an RAF flying student might do at low level over his girlfriend’s house to say, “I got the 24-hour pass!” This manoeuvre is a traditional killer in the wrong hands or the wrong aeroplane. I think we can include the Bulldog in the latter category ? it’s no aeroplane for low-level spotting. It is quite happy making steep turns but you need to keep the speed up and you can’t see much at speed.
That’s it for the manoeuvering, so on to cruise performance and circuit work. We settle at 23in and 2,300rpm, producing 110kt, making this quite a fast cruising aeroplane. The view is superb (low set and relatively slim wings help) and the headroom and elbow room make this an exceptionally comfortable machine.
Stuart reckons its greatest virtue is that you can fly training sorties all day and not get tired. I imagine the visibility would be particularly valued in a busy RAF training circuit. The aeroplane is stable and will fly hands-off while you muck about with charts and checklists.
However, it won’t steer on rudder alone ? the nose drops more than the aeroplane yaws unless there’s a hand on the stick. In no time at all we’re back at Prestwick, cleared for a left base join to one of the vast runways. You need to use the trim wheel in the circuit and the trim is nicely geared and effective. The flap limiting speed is 100kt or so.
I make my first approach at the intermediate flap setting. It’s an easy aeroplane, flying smoothly down the approach at 70kt with a good view and responsive controls. In the flare the elevator is fairly heavy, which makes things easier in a way ? less risk of pilot-induced oscillation ? but also more difficult as it’s harder to be accurate.
There’s a fairly brisk crosswind and I make a crabbed approach. I straighten up a touch early and we’re drifting a little when the wheels touch. The nosewheel comes down quickly after the mains and I think I might have made a better job of holding off. Was I fooled by that heavy elevator? We don’t bounce, but I’ll bet this isn’t a bouncer.
I try the brakes and we get judder, so I leave them. We’re slowing, so I retain the flaps at intermediate setting and open the throttle to take off for a final circuit. The acceleration is quick and there is some torque to counter with right rudder, which is good (in a trainer).
We climb at 700fpm and I relax and enjoy the fabulous view of coast and town. Ayreshire is famous for its scenery and history. Stuart says it’s okay to make a tight circuit and in no time we’re close in on base leg, rather high. I cut the throttle, lower full flap and make a steep side-slipping turn from base to final, losing height at a satisfactorily high rate, and continue side-slipping down short final. Lovely feeling in such a responsive aeroplane and the control forces are light enough at this speed.
The view of the runway is breathtaking. I level out over the numbers and hold off to the bitter end. Having full flap helps us to lose speed. I’m conscious of pulling quite hard on the stick to keep the nose up and the ground at bay.
Even so, we touch down ? definitely main wheels first ? a little sooner than I expected and the nosewheel comes down almost immediately afterwards. “Short-coupled undercarriage?” I suggest to Stuart, adding, before he has time to answer, “Or perhaps a forwards C of G?”
Whichever it is, it’s slightly inelegant in this otherwise elegant machine. But that’s the character of the Bulldog – outwardly graceful, inwardly strong and rather military.
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