> FLIGHT TEST

WORDS Francis Donaldson RFC REALITY IN A WW1 SCOUT Displaying a replica with the Great War Display Team

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p032-040.flighttestV2FINAL.indd 48 21/12/10 19:23:28 RFC REALITY IN A WW1 SCOUT Displaying a Sopwith Pup replica with the Great War Display Team

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READ any account by a First World War pilot of the Royal Flying Corp who lived through the 1917-18 period, and the Le Rhone rotary powered Sopwith Pup always seems to be quoted as the most delightful to fly of all the scouts of that era. Not the best warplane, for by the time it was in widespread service its performance and firepower were inferior to contemporary opposition like the Albatross - but the Pup was dainty, willing, joyful – ‘you could do anything with it’. Later Sopwith models like the Camel and Snipe were more powerful and militarily effective but more vicious in their characteristics, whereas the government- designed SE5 was fast and a brilliant gun- platform but lacked the Pup’s sparkle. Not surprising then that when I happened to be in the right place at the right time to experience a replica Pup, albeit radial powered rather than rotary, I was quick to take up the offer. G-BZND was built as an LAA project by Brendan Goddard in the Southampton area. Started in 1989, Brendan built the aircraft in a very modest lean-to workshop at the back of his house, under the supervision of local PFA inspector and vintage aircraft guru Ron Souch. The aircraft was built from the ‘Replicraft’ drawings, which are tracings of the original Sopwith blueprints, re-formatted onto a few large sheets and primarily intended for use by model makers. To complete any plans-built project is a massive achievement and that Brendan built such a complicated craft as the Pup in such minimal facilities was outstanding. Wood and fabric aircraft of the First World War era With a speed were not designed with simplicity of build differential of only 5-10 as a priority. Unsure of the reliability of the knots, it’s hard to catch glues of the period, Sopwith’s aircraft used your prey if you mis- wooden members held together by complex jdge the ‘pounce’. metal fittings folded from flat mild steel sheet, bolts, rivets and piano wire bracing wires, tie rods and compression struts, all tensioned up by literally dozens of turnbuckles – a labour- horsepower at 2550rpm, which at first sight wife, Mary, was determined to see the aircraft intensive form of construction that was to seemed a suitable more modern (1940s) airborne and displayed before the public in be rendered obsolete a decade later by de substitute for the 80 horsepower Le Rhone Brendan’s memory. Havilland’s brilliantly simple glued together rotary fitted to the originals. Mary was introduced to Sopwith aficionado ply-covered wooden box . Things are not always how they seem Ernie Hoblyn, who had rebuilt a Sopwith A stickler for realism, Brendan wasn’t however, and when the Pup was assembled for a few years previously along with one to make his replica with a welded steel initial taxi trials at a strip near Brendan’s home, LAA inspector Dave Silsbury, and had been tube fuselage, like so many of the American the Salmson clearly couldn’t cut the mustard, flying it for many years with the Great War WW1 replicas – he built the whole thing in for it could scarcely get the Pup moving at a Display Team. The Pup was dismantled and the original Sopwith fashion. Not letting fast trot, let alone up to take-off speed. The moved to Ernie’s home field at Watchford standards slip as he neared the end of the problem, predictably, was that not helped by Farm whereupon, acting on Mary’s behalf, he job, he even spliced and whipped the ends of the masking effect of the big radial cowl, 80 extracted the feeble Salmson and re-engined it all the stranded steel external bracing wires horsepower turning a relatively small diameter with a 145 horsepower Warner Scarab, turning in the original manner, rather than swaging propeller at 2200rpm or so was a lot less a 90-inch propeller. them. Likewise, all the fabric rib tapes were effective in producing thrust than the original After having the new engine mount painstakingly frayed-edged rather than pinked. 100-inch diameter prop turned by the Le Rhone stressed by a local ex-Westlands stress man, a Save for the use of modern glues and metals, at 1200rpm. sometimes frustrating exchange of paperwork AN hardware, synthetic covering and paints, Tragically, Brendan passed away shortly and a couple of visits by LAA Engineering’s firewall aft, Brendan’s Pup is pure Sopwith. after, with the aircraft complete but unflown design team, the aircraft was finally cleared The project was completed in 2000, the and unflyable. At this point, the aircraft could for flight in December 2005. It was test flown main concession to modernity being the use so easily have been relegated to a static role initially by Ernie from nearby Bodmin and then of a Salmson 5AQ radial engine rated at 90 in some museum but fortunately Brendan’s by Dan Griffith who had been invited to display

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p032-040.flighttestV2FINAL.indd 50 21/12/10 19:23:35 the aircraft for Mary. portion to the rear of the cockpit. Every bay of With the Scarab engine, the Pup was ‘With the Scarab engine, the fuselage is braced by criss-crossing piano transformed – now it would leap off the ground the Pup was transformed wires taughtened by turnbuckles, and the eagerly and climb away in a very spritely front end is reinforced with large pressed steel fashion. With a Permit to Fly issued by LAA in – now it would leap off frames and wood diagonal struts that would August of 2006, at last the Pup would be able to have originally have provided the mounting for be displayed for the enjoyment of the public, the ground’ the fixed crankshaft that projects from the rear as Brendan had always intended. The Pup of a . remained Watchford-based, but with Ernie The undercarriage consists of a pair of usually at the controls of his the Pup was being designed in late 1915. streamlined steel tube V-struts - in the replica it was my great good fortune to be invited to act While in this period the Germans were more built from Piper Cub lift strut material, suitably as reserve display pilot on the Pup, to take part boldly experimenting with cantilever wings, reinforced, a tie bar assembly and two half- when Dan was otherwise committed. and of stressed-skin wood or welded axles, the whole lot being wire-braced. The steel tube, and even all-metal corrugated bungee-sprung half-axles carry big spoked CONSTRUCTION METHODS construction, British manufacturers clung to wheels built up on specially made hubs, The Pup’s airframe is typical of allied the wire-braced wood formula well into the with motorcycle rims. The tail surfaces are of the period, consisting basically of two wire- 1920s and beyond. conventional WW1 wire-braced, without the braced wood-framed box girders set at right The outside contours of the square-box benefit of trim, horn balance or other latter- angles – the one being the fuselage, the other fuselage frame are fleshed out with lightweight day indulgences. The wooden and the boxkite-like wing cellule. This form of plywood formers and pencil-thin stringers elevators are reassuringly large, suggesting construction, first seen on the French Goupy II which make up the upper turtledeck and blend good longitudinal control, but the squat fin and of 1908, had fully matured by the time the rounded sides at the firewall into the flat rudder seem woefully small – more later.

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p032-040.flighttestV2FINAL.indd 51 21/12/10 19:23:38 > FLIGHT TEST Nigel Hitchman

PHOTO

Walking up to the Pup, whilst its 26-foot span is three feet less than a Tiger Moth’s, overall the Pup seems a bigger machine to modern-day eyes, perhaps because of the bulkier fuselage, snub-nose and tall undercarriage. The tips of the noticeably dihedralled wings are almost ten feet above the ground higher, surprisingly, than the contemporary Fokker Triplane. The broad-chord wings present a huge area of fabric to the breeze – 254 square feet of it in fact, about 10% more than a Tiger Moth in an airframe that has more power. The Pup’s fully loaded weight, at 1250lb, is hardly more than the empty weight of De Havilland’s famous trainer making the Pup’s wing loading on a par with the wispiest of microlights. The pre-flight includes checking that the bottom spark plugs of the Warner are present, tight and connected. After the aircraft has been out of use for a while, to prevent any risk of the dreaded hydraulic lock it’s a good idea to remove these plugs to drain off any accumulation of lubricating oil, so we need to make sure they’ve been put back. Otherwise, as with any vintage machine it’s a regular walk-around paying particular attention to any signs of leaks, cracks, slack This striving for self-sufficiency in your optimum ‘ten past eight’ or ‘ten to four’ angle fabric, loose cables, broken locking wire and biplane gives you a feeling of kinship with for a comfortable ‘pull through’, depending so on. The wheels and undercarriage get a the barnstormers of the 1920s and ’30s, or, on whether its clockwise or anti-clockwise particularly careful scrutiny, for the narrow communally, with the pilots of Alan Cobham’s turning. With a radial though, when turning tyres don’t give a lot of cushioning. The first touring air circus. The downside is there’s a lot the prop by hand you find that as each cylinder set of wheels were replaced with altogether more impedimenta to carry than the Pup’s tiny in turn comes up against compression the more robust ones after the original flimsy set of locker can accommodate. The only solution is propeller blades are at different angles. spokes collapsed, putting ‘ND on her nose. to distribute the bits and pieces into kitbags With the Warner’s seven pots, only two or Most air displays seem to be two-day events, that can be slung behind and around the seat three of the cylinders give a suitable propeller so involve a couple of nights away from home with bits of cord tied to the fuselage bracing position for a safe ‘swing’. To further complicate – more, if the weather turns sour for the return. brackets – taking care not to interfere with the matters, the Warner’s impulse magneto only You may find yourself operating from the ‘live’ and rudder control wires beneath. ‘impulses’ with every second compression, so side of an airfield remote from support staff and every other ‘blade’ is a dud. snacks, so you have to take not only toiletries ENGINE START The result is that rather than just being able to and a change of clothes, but also tie-downs, Starting technique for the Warner 145 is swing blade after blade until the engine starts, cockpit cover and basic tools. unusual. There are no electrics fitted to this hand-swinging the Warner involves carefully A safe display depends as much on the pilot one so she has to be hand-swung. With turning the propeller slowly, with switches off, being on top form as the aircraft, so a sun hat, more familiar engines, the crankshaft (and through several unusable compressions before sun screen, food and drink to look after one’s therefore, the propeller) is at the same angle getting one you can do something with. When sugar, salt and liquid levels are equally as whichever cylinder is ‘on compression’, and you find one where the prop’s at an angle you important as a spare litre of ‘straight 100’ for the the propeller can be bolted onto the crankshaft can get a good purchase on and the magneto’s engine. in such a position that the prop is at the impulse is poised ready to click, it’s ‘contact’

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p032-040.flighttestV2FINAL.indd 52 22/12/10 09:34:33 Brendan’s replica follows original construction faithfully. Note huge area of wing – 10% more than a Tiger Moth.

and a powerful swing through in an attempt at ‘This striving for self- is quite a physical labour, and as you work a start. If she doesn’t go at the first attempt, it’s up a sweat it becomes progressively more switches off and turn, turn again until another sufficiency gives a difficult to concentrate on proper sequencing. good blade comes around. Occasionally, for variety, she will either kick As you can imagine, this involves a lot of feeling of kinsmanship back or, for a party piece, not fire on the blade ‘switches on’ and ‘switches off’, where proper you pull through but suddenly burst into life sequencing is critical to safety. The Warner with the barnstormers’ as the propeller rocks to a stop. No matter how could easily take your arm off if it were to lifeless she seems it’s essential to wait until the fire unexpectedly when you were pulling it prop has completely stopped moving before through slowly on what you thought was a throttle closed and switches off, feeling for any reaching for another go. dead compression stroke. Helpfully, hidden signs of the dreaded hydraulic lock. Another One of the very nice things about the Warner behind a removable panel in the starboard side four pumps on the primer and another six is that once it starts, it settles instantly into a panel of the fuselage nose there’s a second pair blades. Carry on a few more blades, listening smooth idle, unlike some other radials there’s of magneto switches, wired in parallel with the carefully to the click of the magneto until you’ve no need to keep her tickled up with the primer cockpit set, so the prop swinger can take charge got a blade you can use. Now have your helper or jiggle with the throttle to keep her going of this himself during the starting operation, open the throttle fully for a second or two, utter while she warms up. She ticks over happily rather than trust to shouted communication a short prayer, throttle set and contact on the at 500rpm with a lovely rumble from the stub with the bod perched up in the cockpit. left mag only, the one with the impulse. A good exhaust. Time now to ease your way carefully The plunger-type fuel primer is also under heave-ho on the prop. Usually, she will start between the spinning propeller and the right this panel. With a cold engine, the Warner likes from cold on the first couple of attempts. lower wing’s leading edge to switch on the four slow, steady strokes of the primer followed When hot she can be more difficult, playing second magneto, check the primer is screwed by pulling through six blades to suck in with listless and hard to get. Propping the Warner in and re-fit the engine-turned access panel.

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Author Francis Donaldson with the Great War team’s Pup which he flies in displays.

CLIMBING ABOARD your face from crash-impact with the breech of Getting aboard is a case of grabbing the cockpit the replica Vickers gun, is low enough that at a surround from the left hand side, right foot stretch you can look over it. into a leather pocket built onto the bottom The stick, topped by an oval grip, lies against

, stepping with your left onto the the instrument panel when the aircraft’s at rest, PHOTO Nigel Hitchman aluminium toe-plate that’s fitted to the root end for control stops weren’t used back in 1916. The of the rear spar, and then swinging your legs rudder and steerable tailskid are controlled by high over the coaming to stand initially on the a rudder bar, with toe straps to keep your feet seat. Short-legged pilots may struggle with this, from sliding off it at full deflection. A neat brass and I know one LAA’er who abandoned the throttle quadrant adorns the left hand side of idea of building a Pup because he was afraid he the cockpit, while on the right hand side there’s might need a ladder to get in. a dummy hand pump which in the original Taking hold of the rear cabane struts for machines would have pressurised the fuel tank support, and lowering yourself into the small to start fuel flowing to the rotary engine. bucket-shaped wickerwork seat, you step On the panel, there’s a conventional modern because the Pup is so short-nosed that carefully onto the wooden heel boards, for the ASI, tachometer and Ts and Ps for the Warner, there’s scarcely a couple of feet of clearance cockpit floor is nothing more substantial than which work well, plus an old fashioned between the tall wire wheels and the prop, so the aircraft’s fabric covering. The fixed seat altimeter and compass which are more for without due care it would be all too easy for puts your shoulder level well above the cockpit appearance than utility. An inverted U-tube the chocks or the chock puller to get tangled coaming which cuts uncomfortably across your bubble gauge takes the place of a conventional up in that lethal spinning club. Chocks with back. The vertical windscreen with its thick slip indicator. A pair of old bell switches ropes attached are favoured, so you can stand padded tubular surround, designed to protect control the magnetos, and there’s a dummy well clear, but if a chock jams under a tyre it’s starter magneto handle to further add to the better to crouch down and work it out by hand impression of a 1916 environment. Another than by heaving on the rope, lest it springs out small lever purports to control the fuel cock, suddenly and bounces forward into the prop. and sure enough, this one isn’t a dummy. Taxiing the Pup is nerve-wracking because of The originals only had a lap strap for the pilot the poor forward view in the ground attitude, but to comply with modern requirements the the lack of brakes and the variable, often non- replica has a four=point harness. Unless you’ve existent, directional control. So much of the remembered to lay the shoulder straps out landscape is blotted out ahead by the cowling over the rear turtledeck before getting aboard, around the radial engine that it would be all there’s no way you’re going to be able to reach too easy to taxy into another aeroplane without them now without external assistance. The seeing it, let alone the signboards, traffic cones cockpit sidewalls are graced with a mass of and suchlike which airfield operators leave out exposed bolt ends, split pins and turnbuckle as traps for the unwary biplane pilot. Seeing wire-locking which will snag and rip your flying where you’re going relies on swinging the jacket if you try swivelling round in the cockpit nose from side to side to look ahead, but the to reach the strap ends, by now dancing in the steerable tailskid seems very ineffective and slipstream. turning relies on blasts of propwash over the By the time you’re comfortably buckled in, small fully-deflected rudder. Those cart wheels and have managed your cockpit resources in give very little rolling resistance, particularly terms of stowing chart, hand-held radio, GPS, on sun-parched ground and close-cut grass – donned headset and so on, the Warner has and don’t even think of taxiing on tarmac. In warmed enough for a run-up and magneto the absence of brakes, bursts of power to get check against the chocks. She never seems to some directional authority lead to an alarming oil her plugs while idling, so providing you’ve increase in speed. remembered to switch on the second mag at Add the slightest downslope or tailwind into Warner Scarab radial engine instead of the the front end, all’s usually well. the equation (for example when backtracking original 80hp Le Rhone rotary... works well. Pulling the chocks needs particular care the into-wind runway) and you have a real

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p032-040.flighttestV2FINAL.indd 54 21/12/10 19:23:52 problem on your hands – especially if you ‘Taxiing the Pup is inches at their trailing edges. happen to be at the back of a formation of The problem is that the circuit takes equally unpredictable machines. Sailing nerve-wracking... poor in the upper and lower wings rather than, as men have a flag they can fly which signifies to in most four-aileron biplanes, mostly in the surrounding vessels ‘I am manoeuvring with forward view in the bottom wing with the upper slaved off difficulty’ in such situations, which is nautical- the lowers. Consequently, while the down- speak for ‘I am out of control, keep clear’. ground attitude, lack going aileron is pulled by the stick torque-tube Taxiing the Pup, I’ve often wished we had assembly through about 12 feet of stranded similar coded signals available to us. of brakes and variable steel cable and one pulley, the up-going one Once at the hold, there’s little to check. We is activated via more than 30 feet of cable, can’t do much of a run-up without rolling directional control’ including the balance cable right across the forward, but we’ve already opened her up upper wing, three pulleys and at least eight against the chocks so all should be well – if on to keep the Pup straight in the climb, and connections, all which introduce stretch into in doubt we can do a crude mag check by looking down, are reassured to see the slip the system. momentarily flicking the switches off in turn bubble pretty much centred. Rate of climb, Once you get to know the Pup better you find as we open up for takeoff. There’s no trim against the stopwatch, is around 800 feet per that with all that dihedral, leading with the or throttle friction. Mixture is always rich, minute. You keep an eye on the CHTs in a rudder and helping with the ailerons does give mags and fuel on (according to the little lever, prolonged climb because cooling a radial in a you an acceptable roll responsiveness – not anyway) and sufficient (we used a dip-stick rotary-type cowling, it’s difficult to get enough what you’d call a roll rate in the normal sense before start-up). There’s no flaps, no gyros, airflow past the top cylinders. After a couple of but adequate for an exciting display. Where no hatches but harness is OK, controls are full minutes in the climb the CHT is approaching you have to be very, very careful however is if and free. Eventualities – if the engine stops on the 425 degree F ‘red line’ so we level out – you hit turbulence (or another aircraft’s wake) takeoff there’s plenty of runway ahead, and these old radials are far too rare and valuable to near the ground, when it can be disconcerting good fields beyond the trees. risk distorting the heads through overheating. to find yourself banking to a precipitous In the cruise, if one can call it such, at 1750rpm angle despite generous recovery rudder and WE’RE OFF! indicating 70 knots the first thing that strikes full opposite aileron being on, and you have The Pup moves forward smartly when you you about the Pup is how ponderous are its to wait for the controls to take effect. In this open the throttle, and within a fuselage length ailerons, for despite the fact that there are four situation it’s best to check forward on the stick the elevators become effective and you can of them they seem almost ineffective. Later, to reduce the angle of attack, trading height raise the tail, prodding the rudder bar to keep when you get a chance to study them, you see for controllability, for the controls bite quicker straight. A couple of skips later and she’s off that even though they move through generous when the wings aren’t lifting so hard. the ground and climbing away like a hot air angles on the ground, once airborne you can balloon at 45 knots, building to 55 for better push the stick sideways as far as your calves STABILITY engine cooling, rpm indicating 1900. will allow but the response out at the wingtips Longitudinally, despite the generously You realise you’re holding a bit of right rudder is that the ailerons only deflect a couple of sized tailplane, the Pup is slightly statically

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unstable. Ernie has managed to curb its wing tip touches the ground, with a risk of the original nose-up trim by jacking up the leading ‘Opening the throttle undercarriage collapsing sideways. If you’re edge of the tailplane and fitting a cord along the takes a fair bit of nerve quick off the mark, when a swing develops you upper surface of the elevator trailing edges, so can arrest it before it gets out of hand using it’s no longer necessary to keep a forward force if you’re pointing at a burst of power and forward stick. Opening on the stick all the time, but if disturbed she is the throttle takes a fair bit of nerve if you’re now equally likely to nose up towards the stall something expensive pointing at something expensive like someone or head for the ground. This is symptomatic of else’s aeroplane, or a hard and immovable the very short nosed configuration and a centre like someone else’s object like a hangar. of gravity that at the aft limit is at roughly 40% The technique which the Shuttleworth pilots of the mean chord. Not acceptable in a modern aeroplane’ use with their original rotary powered Pup aeroplane, these characteristics are part is to always do a three-point landing, which and parcel of the contemporary thinking on established a bank she will turn in a very small gets the tailskid dragging in the ground as maximising in-flight manoeuvrability. space using very little pressure on the stick. soon as possible. Their idea is to maximise The saving grace is that the pilot is so much For the quickest turn-around, a wing-over aerodynamic drag and tailskid friction and out in the open in the Pup, and so conscious of is even more effortless because at the top of have the aeroplane come to a halt in a very the airspeed and ‘g’ being pulled through the the manoeuvre the airspeed is low, the angle short distance, almost before it has had a feel of the controls, pressure on his posterior of attack virtually nil and the roll force input chance to think of ground looping. The other and quivering of the rigging wires, that needed to produce the about-face are much method, favoured on ‘ND, is to do a tail- longitudinal control is a subconscious task. less than in a normal turn, so the manoeuvre low wheeler which allows you to ease the Laterally, she’s very positively stable feels better co-ordinated. aeroplane very gently onto the mainwheels, thanks to the three degrees of dihedral on establish her rolling straight and true with the both sets of wings, which means that rudder LANDING TECHNIQUES tail still up and with good directional control, inputs produce lots of sympathetic bank, There are conflicting opinions as to how best to and then let the tail down gently when you’re as described above. This makes the rudder land the Pup. With such a low wing loading she ready as the speed bleeds off, by which time feel quite effective. On the other hand if you lands very slowly, and is quite happy to round you can focus your attention 100% on the consciously analyse the rudder response, it out off an approach rumbling in at as little as directional control aspect of the job. This is noticeable that even full rudder either way 45 knots. By biplane standards, the view of wheeler technique is a lot easier to carry off doesn’t yaw the Pup through more than about the landing area on approach and through with the progressive throttle of a radial than 10 or 15 degrees, and she’s neutrally stable the touchdown is not bad. Putting her on the the rotary’s blip switch. directionally feet-off. In practice, given the ground is no different to a Moth. When you land into a breeze, there’s no nature of the machine, this isn’t a problem and The issue is that the Pup’s low fin and rudder problem because the touchdown speed is keeping in balance soon comes naturally. are almost completely ineffective once the tail reduced and by the time you lose directional With such a low wing loading, stalls in is on the ground. Without the benefit of brakes control you’re just about stopped anyway. the Pup come at around 35 knots indicated. and being, like all taildraggers, directionally The difficulty comes when landing in calm Despite the sharp leading edge of the thin, unstable once the weight is on the wheels conditions. Crosswinds? Best avoided at all undercambered RAF 15 wing section, the stall rather than the wings, she loves to ground loop costs, so the Pup can only really be used from is a gentle affair with the nose falling through towards the end of the ground run. For some an airfield with multiple runways or a patch of reluctantly, with not a hint of a wing drop. It reason it always seems to go to starboard. If grass somewhere big enough to find an into- pays not to be complacent though, for a few it happens at a steady trot, it’s no big deal – wind run. Runways hadn’t been invented back years back another replica Sopwith Pup spun providing of course there’s nothing in the way in 1916, aeroplanes just flew off fields. in during its first flight and was written off, – she simply turns smart right at the end of the fortunately without serious injury. roll, and comes to a halt. On the other hand, if it FUN TO FLY? Where the Pup excels is in manoeuvrability, happens at 20 or more miles an hour there’s a OK, that’s the technical aspects, is she fun to for with such a low wing loading, plenty of lot more energy involved and as she exits stage fly? On a cross-country flight, after an hour or so power and relaxed pitch stability, once you’ve right she’s likely to tip over until her left lower she can get quite uncomfortable – the cockpit

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‘With the pitch instability SOPWITH PUP REPLICA you can’t let go of the stick for more than a few seconds at a time’

cluttered by suspended bags, cockpit cover and tiedowns which leave you precious little elbow room. The wicker seat is too low-backed to offer any kind of spinal support, and the coaming presses against your shoulders relentlessly. The slipstream roars around your ears and your flying helmet flutters constantly against the top of your head. A close-fitting pair of goggles are a must. With the pitch instability you can’t let go of the stick for more than a few seconds at a time, and if you try to manipulate the chart single- handed you find there’s such a whirlwind going on in the cockpit that the folded demon thrashes about like a thing possessed. If you try to monitor the Icom then the assault on your eardrums becomes even more severe, for the unshielded ignition of the Warner sends a painful intermittent but persistent percussive crackle to the headset that bursts into your consciousness over the background din. With a relic of a compass that only shows the cardinal points, and prone to rotate constantly with engine vibration, navigation is by memorised line features and stopwatch backed up by pocket GPS - this season the trusty budget moving-map ‘Aware’ unit has been a real bonus. There’s fuel capacity for two and a half hours, but with a cruise speed of just 65 knots (70 if you concentrate on keeping her on the step), taking her to displays often involves a planned two-hour flight. With these low cruise speeds and narrow margins, the effects of headwinds need very careful consideration and diversions and decision points planned. There are just not many airfields around that have the luxury of multiple grass runways and 100LL for sale that won’t be phased by the non-radio arrival of a wandering WW1 scout. Once you get to a display site, it’s a great relief to off-load all the stowed paraphernalia and fly the display proper, for this is where the Pup becomes a real joy. With up to ten replica WW1 aircraft flying a set piece within the airfield SPECIFICATIONS boundary, between one and 800 feet up, the Pup’s small turn radius, respectable climb, (Original aircraft) Useful load 199kg and the good in-flight view from the rather exposed seating position makes this Sopwith PERFORMANCE POWER a splendid mount. She’s not fast, of course, and Max speed 97kt 80hp Le Rhone rotary you soon learn that if a swooping ‘interception’ Stall speed 35kt of another aircraft goes wrong and you find Rate of climb GUNS yourself a 150 yards behind your prey rather 800ft/min 1 x .303in Vickers than 50, with an overtaking speed differential Climb to 10,000ft machine gun of just five or ten knots it takes an age to catch 14min up. But that was just how it was in the actual Ceiling 17,500ft MANUFACTURER battles, I guess. Endurance Sopwith Aviation Of course, it’s one thing to tootle round the 2.5 hours Company country for fun of a summer weekend with Kingston upon Thames your mates, quite another to have to patrol DIMENSIONS Surrey day in, day out and year-round in sub-zero Wingspan 8.08m temperatures at 15 or 20,000 feet, hunter and Wing area 23.6sq m REPLICA PLANS hunted, riding a petrol-fuelled tinderbox with Length 5.89m Replicraft no parachute. No Aware unit to guide you home Height 2.87m Jim Kiger either! 1400 Gomes Road In 30 or so hours flying her over the last WEIGHTS & LOADS Fremont, CA 94539 four years this aeroplane has provided some DETAILS Seats 1 USA brilliant experiences, not a few heart stopping A labour of love: Sopwith Pup built from plans Max weight 557kg T: 00 1 510 656 6039 moments but most of all a very strong respect based on original technical drawings and uses Empty 358 kg W: www.replicraft.us.fm for those very young men who took such period correct construction methods. machines to war 90-plus years ago.

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