FLIGHT TEST

The British Bulldog

Clive Davidson flies one of the last ‘old world’ British production light singles. Pictures by Neil Wilson

Flight Test

You might be aware of a timely and brilliantly functional public relations exercise from May 1940 of the Spitfire Fighter Fund, whereby collections were made to buy much needed Spitfires. Sixpence (2½p) bought a flush rivet, a set of 24 spark plugs cost £9.12s (£9.60) and £1,600 paid for eight .303 machine guns. An entire Mk II airframe and Merlin XII was said to be valued at £5,000, but this is often quoted as a seemingly appropriate figure, not a costing to reality. There were 1,400 such schemes, with many of the resulting Spitfires proudly wearing the funding town’s or company name on the cowlings. My favourite is an example funded by the Kennel Club, who named theirs Dog Fighter.

Our air test aircraft

Leaping forward 70 years, the fashion of naming aircraft is now rarely seen. However, there is a penchant for some imaginative owner pilots with personalised ‘G’ registrations. Some aptly fit their name, and the one on this month’s air test subject injects a touch of light-hearted humour, while underlining the machine’s robust character and capable performance. G-GRRR is a Scottish Aviation Bulldog, an aircraft that raises a smile both from its reg and from its delightful flying characteristics. The aircraft is operated by John Mann’s syndicate and, quite some time ago, I had the challenge, task and the fun of checking out some of the owner pilots. It’s an aircraft I still have an occasional ‘flit’ with, as John renews his aerobatic currency with me and, at the tail end of our soggy winter weather just before the GA shutdown, he diverted into Henstridge, returning from his maintenance check as his home field was still waterlogged. We grabbed the opportunity of a flight test and an air-to-air sortie, and though G-GRRR has a CAA CofA, we do of course have Permit to Fly examples on our LAA fleet. A quick call confirmed that Patrick Caruth was free the next day, and his BN Freelance was serviceable and ready to take advantage of the forecast for bright sunshine and slack winds – so we were set.

A sorry history

The Bulldog followed on from the Beagle Pup, itself a successful two-seat, all metal trainer of either 100hp or 150hp engines, and before a sole prototype demonstrator four-seat retractable version, the Goldfinch, which saw the lineage peter out. The manufacturing company, trading as Beagle, British Executive and General Aviation Ltd., had been formed by the amalgamation of both Auster Aircraft and FG Miles Ltd and at one stage were producing a Pup a day. They also had a Swedish military order for 78 of their new Bulldog. The future looked positive, but it all came to nothing when the then Labour Government withdrew its backing before any production Bulldogs were built, and the company folded. Scottish Aviation, at Prestwick, grasped the baton, fulfilling the Swedish contract and going on to build 140 for

the RAF and fulfill a number of smaller orders for air forces around the world. Scottish Aviation eventually being amalgamated into British Aerospace. From the prototype’s first flight in May of 1969 from Beagle’s facility at Shoreham Airport, 328 examples were built, with production ceasing in 1982. Incidentally, that prototype, G-AXEH, resides in the National Museum of Flight at East Fortune, in Scotland.

Romeo Romeo, a Model 122, was delivered to, and flown by, the Ghanian Air Force from 1973 to 1997 when, as one of a batch of six others, it was returned to the UK. All had low hours, RR had less than 500. It was placed on the British register as G-BXGU and operated from out of Old Sarum, close to Salisbury. It was here that John Mann was first introduced to advanced handling, after being given a gift voucher for an aerobatic trial lesson. At the time, John had been flying a Cherokee and having done a bit of touring to France and the Isle of Mull, he thought the contrast of aerobatics was great fun, so he Below The ventral fin and stall strakes coming forward from the tailplane are evident here. It’s quite a height up onto the wing but fortunately there’s a convenient step.

Bottom Cruising at 105kt over the British countryside heading for the coast. Little did we know this would be our last opportunity to do so for a while. continued to gain the AOPA Aerobatic Certificate. Over time, instead of hiring, he bought a quarter share in the Bulldog, and later bought the other members out. On coming onto the civilian register, the aircraft had originally been sprayed a rather garish purple, so John had it redone in its current bright red with silver wing leading edges, plus its new registration letters. I think it is attractively distinctive. He then moved to the ‘hill’, as Compton Abbas is known locally, where he formed his new syndicate. I was also based there at the time and John reminded me that within an hour of his arrival, I swooped in and had convinced him we ought to fly aeros together… I do not recall this, maybe he was pulling my leg, but there just may be a grain of truth in it – I admit I’m not slow in coming forward! Overall, the machine gives the impression of purposeful, robust intent, being slightly beefier than most ‘civilian’ types of its time, with pronounced dihedral, a large fully blown canopy over a wide and tall cockpit, generous fin and rudder area, mass and aerodynamic control balances, spin strakes and a ventral fin, all constructed of conventional light alloy, including the control surfaces. The placarded max take-off weight is 2,350lb/1,066kg and should you wish to engage in aerobatics then the airframe limit is restricted to +4.4 to -1.8 g but, reduce the aircraft’s total weight to arrive at 2,238lb/1,015kg and below, and the airframe will accept the standard +6 -3 g. The type’s tare weight of 1,475lb/669kg, plus two (average) people combine to add a further 383lb/174kg, and a further 237.6lb/107.9kg for full fuel, results in a typical start of play, first flight of the day weight of 2,095.6lb/950.9kg. Obviously, if you’re going on an aeros sortie, you don’t want any loose items in the rear – G-GRRR has only a secure First Aid box and a well-mounted fire extinguisher, which is actually in date! But this large open space can hold up to 200lb/90.7kg of baggage, and the Bulldogs operated by the Swedes had a third seat, making efficient

use of the airborne time for a second student during early handling and navigation training flights.

Wings and wheels

Starting from the ground up, the un-spatted tricycle undercarriage has Lockheed oleo-pneumatic shock absorbers with Goodyear wheels and tyres, with hydraulic disc brakes on the mains. It has direct nosewheel steering and there is a good clenched fist, and more, of exposed chromed nose oleo strut. The book says there is 10.25in (260mm) of prop clearance. Nice to know… The wing is of a surprisingly higher aspect ratio than I remembered. It is not particularly pronounced and I only really noticed this when last standing on the wing walk, gazing at the trailing edge. Later, when looking at Neil’s photos, it was obvious. The wing area is 129.4 square feet, so the max wing loading is 18.15lb/sq ft. The older, but smaller in stature, Beagle Pup from which the Bulldog was developed, is considerably lower at 13.4lb/sq ft. The Bulldog has a larger wetted area and a reasonably tractable, good power loading (weight divided by engine horsepower) of 11.75lb per hp. In contrast the Mk I Pup with 100hp has an adequate power to weight of 16lb/hp but the Mk II, with 150hp, would theoretically better the Bulldog’s straight and level acceleration with 10.66lb/hp. (Between the Pups, the Mk II is not that much faster in cruise, but the difference in the rate of climb is marked). Fuel is carried in two wing tanks, the usable amount being 32 of the 33 imperial gallons/149.8 litres total capacity, and the inboard, underwing fuel drains may be found adjacent and above the main undercarriage. All of the control surfaces are of corrugated light alloy, similar in construction to those on Cessna singles. The ailerons are slotted and have the standard differential of more up than down travel, to reduce adverse aileron drag. There is a fixed tab on the starboard aileron. The slotted trailing edge flaps are electrically driven and have an intermediate position of 10° for take-off and slow flight, and 45° for the approach and landing. There are inboard leading-edge stall strips to disrupt the flow striking the elevators at high angles of attack to shake the stick and warn the handling pilot of the approaching stall and impending doom. The wings are mounted with 1.9° incidence and have a noticeable dihedral of 6° 30min. Like the Pup, the outer wing section has washout aiding the stalling characteristics, and the wing tips are chamfered and house the nav lights. There are underwing tie down points but no trace of the mountings for the previously carried underwing armament package. At the rear, the elevator trim tab is on the starboard elevator, which has mass and aerodynamic balances to bring its centre of gravity forward of the hinge line, preventing flutter and easing pilot control trim forces. At sometime during the aircraft’s development it could well have been found that spin recovery needed some improvement, as the ventral fin is much larger than that of the Pup. However, it does offer the preventative bonus of a ‘tail bump’ at its rearmost point. And, as a precaution against an unlikely tail strike on a rough surface, the bottom of the generously sized rudder, aft of the tail bump, is higher and would be protected from being ripped off should such an event occur. There are also flat triangular spin strakes merging into the aft fuselage from the tail’s leading edge to also aid spin recovery (larger strakes of the same type may be seen on Tiger Moths).

Below John Mann, who bought out the previous group members and now heads up a new syndicate around the aircraft at Compton Abbas. Cockpit capers

Standing on the wing walk, a yellow knob-topped lever, rather similar to a short gear lever, on top of the canopy has to be pulled sharply back to unlock the catch and enable the canopy to be pulled back on its central upper runner and edges. Then, before stepping into the cockpit, clear the harness and support yourself with one hand lightly on the frame of the forward screen and step in. Settled in the comfortable right-hand, leather-bound seat, with the forces style five centrally buckled straps adjusted, chart and note book in the fuselage side pocket and spare reading glasses in the central elbow rest box, all is well with the world. This is a satisfyingly large cockpit, being 3ft 9in /1.14m at its widest point and 3ft 4in/1.02 m at its tallest, literally bags of room above one’s head, even when wearing a helmet.

My two bête noires – the fuel selectors and the headset plugs – I know from memory, but I suggest you too would be flummoxed the first time in. The rotary fuel tank selector is out of view, hidden between the baggy, flight-suited trousers of the parted legs of the chap in the left-hand seat, and just behind the main wing spar. But no matter how hard you focus on the panel, the edges, the top and lower sections in front of you, you will not see those two metal rings of the mic and phones plugs. As they say in panto, ‘Behind you’, both P1’s and P2’s sockets are behind the central elbow box. It is best to plug in before strapping in, as quite a head craning twist is needed. But I have heard of worse. Imagine Buccaneer pilots whose cockpits were so tight on space that an

added transponder was fitted behind the seat, hidden from you. When changing the ident, they had to count the tactile clicks on each of the four rotary numeric selectors, with gloves on. Amusing to contemplate in the warmth of a club cafe with friends. Remember those? Gatherings and friends, not transponders...

Instrumentation

Feet and hands naturally assume their position on the pedals and the black, finger-contoured control column grip, the stick curving under the panel and, when wiggled and holding its twin, there is no play whatsoever between them. Checking the throw all around the box, there are no

Left Extra weight over the Pup was partly offset by increasing the wingspan with an additional centre section, there’s a noticable crank in the wing just outboard of the walkways.

Below The nicely turned out traditional panel and plush cockpit has ample width and headroom for a two-seater.

Below right The generous fin and rudder give the Bulldog a very generous 35kt crosswind limit. Note corrugated elevator skin. potential wires or obstructions to falsely limit any induced movement and looking outside at the ailerons shows them to move without any slackness with their rod connections.

The rudder pedals are broad and generously sized to accommodate near clumsy military footwear and, much to my liking, are the brake pedals immediately above. Closing the throttle fully and raising your toes there can be no likely mis-braking because the toes cannot find the brakes, it’s a one-shot score. There is also a pull to engage park brake pull handle sprouting from the corner of the lower left panel, adjacent to the pilot’s right knee. The lower, central, mid-panel houses both a suction gauge and a combined Volts and Amps dial and below are the three switches for the master, alternator and fuel boost pump. A red engine starter engaged light is right beside the magneto and starter key position. The panel continues between the seats and houses the throttle quadrant, which indeed has four levers, all separated not only by function and colour, but helpfully by shape as well. The closed black throttle lever is the largest, having a lateral handle; the slim royal blue propeller lever is correctly fully forward, in the fine position; the red ball mixture lever is fully aft in the lean/cut off position; and the smaller, side placed friction lever is forward and free. The engine they are connected to is a Lycoming IO-360 (injected and horizontally opposed), configured for aerobatics and giving us 200hp through a Hartzell two-bladed constant speed metal propeller. Conveniently behind these levers are the elevator trim wheel, the rudder trim – flat mounted with a small, red pointer nose and a graduated scale for deflection and use. There is a very thin, almost ignorable scratch of a line at the one o’clock position showing the take-off position. Right rudder will be needed for take-off and this will reduce the pressure and aid a ‘young’ (inexperienced) pilot’s right foot work to keep on the straight and narrow. A flat and black ‘flap’ electric switch with deflection for ‘inter’ (take-off) and ‘full’ (landing) is the last item of this set. There is a central bank of avionics, which contains the 8.33 radio, and in front of the P1 are the six basic instruments and to the left an ADF indicator and beneath

that one for the VOR . On the lower row, left to right, is: a clock, a twin needled fuel gauge, a combined manifold pressure and fuel flow meter, the rpm gauge and next to that a tri-indicator of the CHT and oil temperature, both in °C , along with oil pressure. Beneath these are the black-topped circuit breakers for all of the facilities, one orange illuminated press to test ‘Boost pump on’ and tumbler switches for all of the lights – anti-collision, nav, landing and taxi, followed by an avionics master switch.

The right-hand panel has placards for limitations and aerobatic speeds, and vent and heating slots. A Hobbs meter and a carbon monoxide indicator, which still remains orange. It’s lovely to see such a nicely turned out ‘traditional’ panel, so many of them have been chopped and changed, with instruments missing or inoperative. Above, the lateral handle may slide the canopy forward and lock it, but beware the wire locked yellow and black wasp stripped handle behind. Pull this and you are in trouble, it’s the canopy release. I have never, as yet, had to pull one. However, in the Yak 52 the same red ball that shuts the canopy tight, in the same company's Yak 11 and earlier Yak 3 and 9 fighters, is the canopy release! D’oh. The Bulldog canopy may be flown slightly open, but not something I could recommend, not just from the concern it might cause an aerodynamic difficulty, but a flapping and distracting chart disappearing act would be nigh impossible to follow. The checklist to start the engine from cold requires the master switch on, the fuel tap turned on, and the red mixture lever on the throttle quadrant forward for rich. The throttle is open a quarter to half an inch forward to anticipate a starting rpm of 1,200. The electric fuel pump is flipped on and accompanied by the reassuring whir of the motor until fuel pressure is shown, then off. The mixture lever is then brought back to the fully lean / cut off aft position (being an injected engine, should the mixture lever remain forward during the start, an excess amount of fuel will enter the cylinders and become too rich to 'fire' and start the engine). The starter / magneto key (check all clear and call ‘All clear’) can then be engaged with your other hand ready to slide the mixture from lean forward to enrich the mixture, as the engine first shows willing encouragement and fires, too slow to do it and the engine will stop. With time and an acquaintance established, this last action of the sliding forward of the mixture lever will be a smooth, calm movement, not a slammed hurried jolting thrust against the stop! The oil pressure needle rises reassuringly, and the red starter engaged light, rather oddly placed down by the ignition key in the centre panel rather than in the pilot’s natural line of sight, is out. Engine warmed, taxying and the lookout over and beyond the nose is simple, with a good turning circle of approximately 30ft through the direct rudder to nosewheel steering and a little anticipation on a concrete or Tarmac surface. The prop is cycled three times from 1,800rpm and the blades can be heard thrashing as they coarsen. The manifold pressure needle rises as the Lycoming works harder, and incidentally has the fortuitous action of cleaning the plugs (should they be dirty with carbon). Mags are checked at the higher rpm of 2,100. Throttling back to a calm idle, we can now settle to prepping for flight with the fuel system selected and boost pump running, flaps and trims (don't forget the rudder trim to one o’clock) and self-brief for all three take-off emergencies – we have ahead and to the right some 400 yards (I’m a pre-metric man) the standard ‘get out of jail free card’ of the field I hope I never have to walk back from. Boy Scout stuff – be prepared. On the 24 numbers, with the runway centreline extending 720 metres ahead, we have ample space to roll and climb. RR can be kept on heading and the torque and slipstream produced by full power and a fully fine prop setting pulling to the nose to the left does not feel that pronounced. We easily lift the nose wheel as we pass 55kt just after the diagonal taxiway, in just under 300 yards and we are quickly off and accelerating in ground effect,

aiming to climb away at 80kt with the VSI showing just over 1,000ft min. The flap is raised judiciously as we pass ‘our field’ with an anticipated slight nose sink caught with the stick and retrimmed. Power and prop came back to 25/25, a convenient set of numbers, throttle back first so as to not over square, 25 inches of manifold pressure and the revs settle at 2,500, producing what seems to be a sigh and a reduction in noise. Minute adjustments of the trims are made – they are there to help and relax you. Trim and trim again to the finest degree. We establish a cruise at 105kt with 23in and 2,300rpm, and lean the mixture. We’re burning 35 litres an hour. Checked from steady, heading side slips, both in the cruise and set up for the approach, releasing one control at a time the Bulldog shows herself stable both laterally and directionally. There is a little adverse aileron drag, easily countered with rudder, but single control gently banked turns may be flown with little divergence. She is also stable in pitch from nose down and nose high releases, the phugoids petering out within three cycles. Interesting to note is that commencing from pushing forward 10° and gaining 10kt, then letting go, we returned exactly to our starting height of 3,500ft. However, start by raising 10° and our cycles dip and rise, gaining height, and unaided we fly level again at 3,800ft. The control

“Checked from steady, heading side slips, both in the cruise and set up for the approach, releasing one control at a time the Bulldog shows herself stable both laterally and directionally”

harmony is near perfect, with lovely friction-free control circuits and no play in evidence.

Aerobatics, a delight

The placard directly in front of me gives the speeds in knots required for the Bulldog’s aerobatic repertoire, as well as airmanship / threat and error management advice: loops 145, half loop and roll out 145, half roll and dive out 85, stall turns, slow rolls, barrel rolls all at 120 and flick rolls 65-80. And being below the max aerobatic weight we can pull up to 6 G. However, it is rare for us to pull beyond 4 G, there is no need to as large sweeping gentle aerobatics suit this machine. Coupled with a brisk rate of roll, the handling is delightful, however we still have to dive to achieve 145kt for a loop using 25/25 – max straight and level speed being 130kt. However, there is the benefit that should you just need that little bit of 'claw' from the prop, you can always push the prop' forward to fully fine. (But I didn't tell you that…) For not quite the first time, I made a concerted effort to actually see what height gain we got from a few manoeuvres. The loop takes us up to arc on our backs at a gain of 530ft when 50kt is shown over the top floating, stick pretty close to neutral but carrying right rudder. And the stall turn took us up 800ft and, if fortunate, you can sometimes judge it to level off at the same height as we started… but the needles only get a snap viewing and could easily be over/under reading at that millisecond scan. On the way up the vertical, there is time to check both wing tips and ascertain that we are indeed on the vertical and not short of it, or on our backs (so a higher starting speed than recommended will give a longer up line). I tend to progressively carry more right rudder to

counter the torque as we get slower and then, at the moment critique, 45, or 60 if you weaken, then full left rudder, more authority and the Bulldog pivots, hopefully, somewhere within the left wing. The ASI definitely has given up the ghost and rests at 0kt, but is soon awakened after a prompt right rudder to prevent a pendulum swing, and a rushing down line establishes on a vertical, held briefly, with an exit to use the energy on another manoeuvre. John admits to being taught the Air Force barrel roll method where one angles off the intended roll direction before introducing both pitch and roll to trace the shape of a barrel in the opposite direction of roll, but prefers, as I do, the competition method. There is a natural tendency to do all rolls to the left and, having chosen a feature on the left wing, commence by diving straight ahead on a feature to 140kt, so as to fly a bigger manoeuvre and then pitch and roll, aiming to be inverted 90° off the initial heading but towards the chosen feature on the left wing tip. Two comments: as more height has gained, the slower the aircraft becomes and the less pitch, back stick pressure is needed to allow the nose to follow its curving path, so, just like the loop at the top there is very little aft stick pressure. As the inverted horizon appears, there is time to judge if the aircraft will be at the momentary wings level at the apex, the top of the barrel roll arc. If it looks like the roll rate is too slow, simply increase the rate of roll so that you are not about to throw height away, gaining energy on a downward curve. Not the best position to induce, ideally your barrelled path will end up by pointing at your starting feature. Incidentally Vne is a massive 185kt and you really have to set a determined stance to achieve this as the wind swirls and swooshes past. Avoid any and all turbulence at such velocities.

Sin Sister 1

Stalls are given plenty of warning, both aurally and with tactility, i.e. the left wing mounted stall warner gives an early warning beep and then a progressively annoyed wail from above 50 to 45, when in the approach configuration the stick judders slightly, receiving the benefit of the buffet generated by the inboard wing ‘toblerones’ thrown onto the disturbed and jittery elevators. Stalling in a climbing turn the aircraft rolls out, and in a descending turn increases the bank, rolling further with a lowering nose.

Sin Sister 2

Yaw + stall = spin, but avoid this over cloud, a monochromatic surface or over an expanse of water. Today though the exit attributes are good; from a one turn spin, left or right, simply place the controls in neutral and all that has to be done as it auto recovers is to pitch from the unusually low nose attitude. Or wait, rotating longer for a fully developed spin, and that beautifully large rudder can be forced against the direction of rotation, pause, stick progressively forward (no aileron input please) and recover from what appears to be the downward vertical. Safe again. Let’s go home. The circuit can be flown anywhere from 85-105kt, depending on traffic, the goal being to be under flap limiting speed by base leg to select one stage of flap to fly at 80kt. While slowing down, the prop lever may be pushed forward for fine pitch to act initially as a brake and to give a better response should a go around be needed. Final and full flap (limitation, operation, indication) now reducing speed to 70. Even though John is flying at this juncture, I run through the generic check of PUFA: Pitch fully fine, Undercarriage (down and welded), Flaps selected fully down, and finally, Altimeter set with QFE. The target is to be at 65 over the threshold, and John knows his aeroplane, putting her down with a gentle squib of the mains and an easing of the nose wheel onto the centreline. There was hardly any wind, but John admits to loving kicking the drift off with that generous area-ed rudder. You would never believe what the Bulldog’s crosswind limit is – an amazingly high 35kt! The ground roll was in the order of under 200 metres (the book gives 153m), certainly no braking was needed to exit at the midpoint turn off.

The Pilot Notes say not to hold the nose off after the mains have touched but to allow the nose wheel to lower itself. It can be held off, but I imagine for a student during primary training this might result in over controlling and a banged tail bump. Looked at from the side, the Bulldog gives the impression of being close coupled, but I think that is an optical illusion as the undercarriage legs are at quite an angle when looked at from the front. All that remains is to say is I always enjoy flying with John in G-GRRR, and I look forward to his next aerobatic currency check. Thanks John, happy landings. By the way, some time ago we ran a Bulldog day introducing pilots to the characterful delights of the Bulldog’s aerobatics. We should maybe think about doing it again… ■

Opposite top The Bulldog is an attractive design, its rather chunky appearance giving it an air of hardiness.

Opposite middle There’s 200lb of baggage capacity and volume to match. The Swedish military had an extra seat installed.

Opposite below The aircraft will climb out at over 1000fpm at 80kt and has sufficient performance to gain height in many aerobatic manoeuvres.

Bulldog Model 120

General characteristics Performance

Crew: Two: student, instructor Length: 23ft 3.06in (7.08m) Wingspan: 33ft 1.85in (10.11m) Height: 8ft 11.5in (2.73m) Wing area: 129.4 ft2 (12.02 m2) Empty weight: 1,475lb (669kg) Useful load: 920lb (417kg) Max. take-off weight: 2,350lb (1,066kg) Powerplant: 1 × Lycoming IO-360-A1B6 of 200 hp (149 kW) Never exceed speed: 185kt (213mph, 343km/h) Maximum speed: 130kt (150mph, 241km/h) at sea level Stall speed: 54kt (62mph, 100km/h) Range: 540nm (621mi, 1,000km) Service ceiling: 16,000ft (4,875m) Rate of climb: 1,034 ft/ min (5.25 m/s) Wing loading: 18.2 lb/ft2 (89 kg/m2) Maximum Load Factor: +6g / -3g