De Havilland Puss Moth Flight Test
PUBLISHED: 12:21 14 March 2012 | UPDATED: 14:12 10 October 2012
The de Havilland DH.80 Puss Moth was designed in the 1920s to provide the flourishing private pilot movement with a comfortable enclosed-cabin-class aircraft for touring. It was inspired by an arduous flight to Morocco in a Gipsy Moth by Geoffrey de Havilland and his wife, Louise...
De Havilland decided that a faster, more luxurious aircraft should be the next step in the growing market − and the idea for the Puss Moth was born. The majority of production Puss Moths were two-seaters in tandem configuration, but a few (most of which were purchased by small charter airlines) were configured with an extra rear seat for this role. The type was initially powered by the new Gipsy III engine which was inverted to give the pilot better visibility over the nose, but later models were fitted with the ubiquitous Gipsy Major engine of 130hp, giving improved performance. Notable design features included folding wings similar in area to the Gipsy Moth’s, allowing operation from short airstrips and
storage in small spaces, and swivelling main landing gear shock-absorber fairings which could be turned through 90º to act as airbrakes.
Wing-folding a one-man job Sitting with its wings folded, test aircraft G-FAVC really does look like a moth poised to launch into flight. The folding mechanism is one of the most interesting features of the aircraft: spreading the wings is a one-man job, taking as little as three or four minutes − although I think it is more practical for it to be done by two, minimising the chance of damage. First, a small spring-loaded pin is pulled to release the trailing edge from the fuselage, then the wing can be swung forward until the main spar pin contacts the wing-locking lug at the top of the cabin structure. A ring pull situated at the wing spar/lift strut junction is then operated, retracting the spring-loaded pin and allowing the wing to move further forward and engage the lug, at which point the ring pull is released. After a visual check that the pin is engaged, a safety catch is turned and the wing is secure. The jury strut that supports the wing when folded is then unhitched, pivoted back and stowed in a clip on the fuselage side. It then just remains to fold down the trailing edge and lock it in place with two spring bolts. Although there is a fuel tank in each wing, there is no need to couple/uncouple the lines as they run very close to the hinge point. As the wings click into place, the fuel cocks in the wing roots feed neatly through apertures in the cabin wall, putting them readily to hand. The fuel gauges are of the float type, with calibrated sight glasses under each wing which are easily seen from the cockpit. Likewise the aileron cables and pitot/static tube stay connected throughout. All very neat – and extremely clever. (One or two modern designers might benefit from studying this mechanism – Ed.) The undercarriage sports long-stroke, rubber-sprung shock absorbers, making for a smooth ride over uneven surfaces. Add to that the differential brakes and a castoring tail wheel, and the aircraft is very manoeuvrable on the ground. (Unfortunately, ’VC’s brakes needed some adjustment, so this particular feature wasn’t evident when I taxied out!) Other notable features are the airbrakes, a tailplane with adjustable incidence for pitch trim, and a long exhaust that runs well back behind the cabin, reducing noise. As with most aircraft of its era, climbing aboard the Puss Moth is a bit of an art.
A step on the beautifully-polished exhaust on the starboard side does help, although access can be gained from either side through the doors. Chrome grab-handles on the door frame/windscreen struts help enormously. Once comfortably seated,
the view over the nose is excellent for a taildragger. The cabin on ’VC is beautifully appointed and, like the rest of the aircraft, absolutely immaculate. The single front seat is a low-back, bucket type with a webbing lap-strap, and in keeping with its period, it has no shoulder harness. Behind this is a similar passenger seat, which can be slid diagonally to allow, in theory, a second passenger to occupy a rather minuscule bench seat (not an option here, as there is no seat belt. Instead, the bench is used for baggage as required.) The seats and cabin walls have been re-upholstered with deep burgundy coloured leather. The cabin walls are clad in a matching cloth, and the whole effect is stunning.
The instrument panel is finished in straight-grain walnut veneer, its top three quarters occupied by a lovely array of period instruments. Below this, in the space previously used as a map locker, are the VHF radio, transponder, GPS, and a grand total of nine switches and circuit-breakers. A large, chromed elevator trim, of the ‘cheese-cutter’ variety, is mounted on the left cabin wall, forward of the door. On the right cabin wall is another cheese-cutter control, which operates the rotating-strut airbrakes. The hand-operated brake lever is mounted on the port door, below the armrest. Throttle/mixture levers and friction nut are mounted on the frame ledge, forward of the door hinge line and neatly lined up with that very convenient armrest. Unusually, the mixture is rich in the aft position and lean when forward. Nigel Reilly, my guardian for the day, was of course very keen that I didn’t forget this − but, as I pointed out to him, a past experience made this quite unlikely: I once operated a Canadian-built Harvard with this configuration, and on my first flight in it as a passenger, the P1 slipped into ‘type-reversion’ mode and we ended up over Cheltenham with a dead engine, looking down at a bunch of back yards and choosing where to crash. With ideas running out, I reverted to instructor mode, applied my FMS checks (F---ing Motor Stopped − Fuel, Mixture, Switches) and on reaching ‘M’ I spotted the error, my lack of familiarity with the aircraft having made me look closely at the position of each lever. I pulled the mixture back quickly, and the engine fired up. I heard later that a lady in the town had called Air Traffic saying she thought our aeroplane was going to crash in her yard. The controller simply replied “So did we, madam!” Another lesson learned. So, after a suitable aircraft and sortie briefing we were ready to fire up the Puss Moth. At present, it has no generator, although the owner plans to fit a wind-driven version on the port wing strut. To save battery power for the essential radio work, the electric starter was not used, and Nigel primed the engine and hand-swung the prop. After a few blades, the Gipsy burst into life and I warmed it up while Nigel clambered into the second seat behind me. With clearance to taxy to holding point ‘Mike’ for a departure from Bournemouth’s Runway 08, the fun began. Keeping a taildragger on a tarmac taxiway with weak brakes, a castoring tailwheel and a ten-knot crosswind was certainly a challenge, and twice Nigel had to hop out to point the nose in the right direction. It was like trying to taxy a demented supermarket trolley! Although it was rather embarrassing, at least we didn’t join the scenery – and the problem has since been sorted. With clearance to take off, and a 90º ten-knot crosswind, I lined up on the downwind side of the runway to allow for any initial swing into wind, and we rolled. Opening the throttle progressively and smoothly, the centreline was achieved and after a short, uneventful roll of a hundred metres or so, the Moth simply levitated into flight at about 50mph, Gipsy rumbling away. It was very gentlemanly – there really is no other way of describing it. Initially the roll rate felt a little slow, but I soon got the feel of it as we climbed away at 60mph, giving us about 550fpm. This with two up and almost full fuel – quite a respectable rate. We met up with the cameraship at 2,000ft for some photography, and twenty minutes later we were done − allowing me to relax and enjoy some less arduous flying. Setting the power at 1,900rpm returned an indicated cruise speed of 107mph, which gives a fuel burn of seven gallons per hour. After the type’s early history of shedding wings (see panel below) an overly-cautious Vne of 120mph was set, and so with just a 13-knot ‘window’ airspeed needs to be watched − especially in turbulent conditions. After conducting the standard HASELL checks, I slowed the Moth down for a stall. Control forces became lighter in roll and yaw, but as the speed slowed progressively the elevator became quite heavy, a strong rearward pull being required (which is no bad thing). The stall itself is completely innocuous and occurs at about 40mph, heralded by a little buffet and followed by a slight nose dip with no tendency to drop a wing. Recovery is standard, with little height loss. It’s all very benign − just as one would expect. After calling Compton Radio we joined on the dead side for a left-hand circuit on 08. On the downwind leg I slowed down to 70mph and deployed the airbrakes, stowing them at 500ft on finals for a fly-by for the camera. The second circuit was flown in the same manner, this time stowing the brakes later. With a warning on the radio of wind-shear due to a ten-knot crosswind over the trees, I added 10mph to the normal approach speed of 60 to allow for any possible loss of speed. Typically, no such thing happened, and the net result was a prolonged float followed by a nice landing halfway down the strip, the into-wind mainwheel and tailwheel touching down simultaneously, followed quickly by the other mainwheel, with no tendency to swing. All very satisfying, and resulting in the inevitable silly grin. The Puss Moth is a lovely, lovely aeroplane, and what a pleasure it was to have flown such a special part of our aviation heritage. I could happily fly one until I hang up my helmet. As befits her looks, she deserves to be treated like a lady − for a beautiful lady she certainly is.
A record-setting type The prototype DH80 Puss Moth,
G-AAHZ, first flew from de Havilland’s airfield at Stag Lane on 9 September 1929. The type was initially marketed as the ‘Moth Three’ before reverting to Puss Moth on its launch in April 1930. The first production aircraft, G-AATC, flew in March 1930 and after design changes including a welded steel-tube, fabric-covered fuselage were incorporated, it was designated the DH.80A. One of the highest performing private aircraft of its era, it was 25mph faster than its Gipsy Moth predecessor. Initially all went well but a series of fatal accidents, involving the loss of wings in the cruise in turbulent conditions marred its future. The problem was attributed to wing flutter caused by unbalanced ailerons and insufficiently stiff wing struts. The problem was solved by fitting aileron mass balances, jury struts and beefing up the wing structure. With its high performance the Puss Moth soon became a record breaker. Notable record flights were Amy Johnson’s 1931 flight from Lympne to Tokyo in just under nine days, her 1932 record flights from Lympne to Cape Town and back to Croydon, and Bert Hinkler’s 22-hour west-east South Atlantic crossing in 1931. However the most famous record-breaking Puss Moth was Jim Mollison’s The Heart’s Content (G-ABXY) in which he completed the first solo east-west crossing of the Atlantic from Dublin to Pennfield Ridge, New Brunswick, USA in 1932 with a flight time of 30 hours, ten minutes. This was the longest non-stop light aircraft flight of the time. The following year, Mollison completed the first east-west crossing of the South Atlantic, from Lympne to Natal, Brazil in three days, ten hours, eight minutes, after which he flew on to Rio de Janeiro. The Puss Moth was a truly remarkable aircraft flown by many of the aviation heroes of the time. In all, 284 Puss Moths were built at Stag Lane. Of these, 25 airframes were shipped to de Havilland Canada’s facility at Downsview for assembly. The majority of these aircraft were flown by the Canadian military and government departments.
Around the world, the type was operated in twelve countries by private owners, airlines and the military.
The last one builtThe last production Puss Moth,
CF-AVC was first flown at Downsview on 4 April 1935 and delivered to Aerovia Ltd of Toronto a few days later. It was stored between 1942 and 1946 and had four owners until April 1958 when it was again put into storage. In 2003, the Puss Moth — by then reduced to an almost complete set of original parts and a Gipsy Major engine — was imported by Ron Souch for collector Richard Seeley, initially being stored at Aero Antiques’ workshops at Durley, Hants. Purchased by current owner Peter Lovegrove, it was registered to Liddell Aircraft as G-FAVC in October 2006. An extensive rebuild by Ron Souch and his team was completed at the end of 2010. The Gipsy Major engine was zero-timed by VinTec at Little Gransden, a new exhaust produced by Unique Fabrications and the engine cowlings were remanufactured by Aviation Panels. After painting by Airtime Paint at Bournemouth, it made its first flight in the UK on 2 June last year. The livery closely matches the paint scheme when the aircraft was delivered to its first owner in 1935. The standard of work and attention to detail are truly outstanding. It could well have just rolled out of de Havilland’s factory, brand spanking new. With its sleek lines renewed, the aircraft now looks as beautiful and purposeful as it ever did.