Curtiss Robin C-1
PUBLISHED: 12:41 29 June 2011 | UPDATED: 14:07 10 October 2012
A pleasure to fly on calm days, though a handful in wind, this elderly three-seater is always rewarding to fly
By Geoff Jones
How many eighty year olds do you know? Chances are some are frail, pale or in care. I recently met an eighty year old who didn’t conform to any of these stereotypes – dressed in vivid orange, out exercising most days and with a spring in her step. Meet the Georgia, USA-based ‘mistress’ of ex-pat Richard Epton, his 1929 Curtiss Robin C-1, named Poachers Pony and also sometimes referred to as ‘the beast’.
As the sun rose over the eastern, wooded horizon and streamed blindingly through the
Robin’s window frames, wing struts and undercarriage legs, we chugged and vibrated along at 83mph in the still morning air. This was an alien form of air travel to me and would be to most pilots – it vibrated, it was noisy and flecks of engine oil were becoming evident on the windscreen. Even though the Robin has an enclosed cockpit and an intercom, we were experiencing flying as it was for our grandfathers.
This is a big aeroplane for a three-seat taildragger: 8ft high, with a 41ft wingspan, with a wing chord that is fully six foot from leading to trailing edge. In comparison a Piper Super Cub is 6ft 8in high, with a 35ft wingspan. This is truly a ‘parasol’ monoplane, one of few where you can stand under the wing without ducking your head. No clipping your forehead on the trailing edge in this aircraft!
What you do have to be careful of are the wing struts and that huge, gangling undercarriage, which owner Richard Epton likens to someone on all fours, their arms outspread, palms flat on the floor. Everything about the Curtiss Robin is different from today’s aircraft. Its tube, wood and fabric construction for a start; the radial engine has its cylinder heads poking through the gesture at a cowling and the main wheels are enormous.
You have to meticulously check all the many visible bolts to ensure they are tight, because the aircraft vibrates so much during flight, there is a tendency for them to shake loose.
The Wright J6-5 engine is designed to consume grease. Richard greases the rockers every five hours and, every twenty, re-packs them completely with new grease. During operations this grease melts and flows with the airstream over the fuselage and windscreen. A wiping cloth is as much part of the paraphernalia Curtiss Robin pilots need to bring with them as a map and some ear defenders. Pilots will also need a ladder to assess the fuel state so they can dip the two 25-gallon wing tanks.
The large tailwheel must be locked for takeoff and landing. When taxiing it is left free to castor, which gives a reasonable turning circle for manoeuvring in tight spaces. The elevator trim predates the Piper Cub’s: the lever in the cockpit alters the tailplane’s incidence.SEATS FOR THREE
Climbing aboard is a bit of an effort, but at least there are leather straps attached to the fuselage frame to help you pull yourself aboard. Seating is for three: one in front and two side-by-side but slightly staggered for better elbow room, behind. There are two doors, both on the right-hand side of the fuselage: a forward one for the pilot and a rear one for the passengers. Seating is in wicker chairs with cushions. Dual controls can be fitted (the ‘student’ behind the pilot), but these are usually removed as the normal pilot seating position is a long way back and has to be moved six inches forwards to accommodate the rear stick, making it uncomfortable and unnatural for the chap in the front seat. Richard has fitted a stick for me for this flight.
The sticks in both cockpits are longer than in modern aircraft, which suggests rather heavy ailerons needing a lot of leverage. Although I’m going to be in the rear seat, Richard suggests that I at least sample the pilot’s seat. The pilot really is in an unusual seating position: your head is a long way back from the windscreen and the panel a long way in front. Also, you sit upright, but with your knees hardly bent and your legs stretched almost straight out.
Richard says it does feel odd at first, but the seating position is actually comfortable and makes sense once you’re used to flying the aircraft. In the rear seat I won’t be able to see the instruments and won’t have any throttle or elevator trim controls. At least I can see the compass in the cockpit roof, it is a few inches in front of the pilot’s head.
Several modern additions have been fitted to make life a little easier. One is an electric system: starter and battery kept charged by a wind-driven generator on the left wing strut. Another is Red Line toe brakes (also used on many Stearman restorations), preferred because they don’t ‘grab’ when depressed. They are used a lot during taxiing because there just isn’t any view over the nose, and even with the ceiling to floor ‘quarter’ windows at the front side of the cockpit, pronounced weaving is the only way to know where you are going. Another modification is to the exhaust, which helps prevent exhaust fumes entering the cockpit and also keeps the airframe cleaner.
The engine exhaust ring has been moved around one station so that the exhaust originally on cylinder No.1 is now on cylinder No.2; this means the exhaust stack which used to spill fumes along the fuselage side is now lower and with a slightly turned down end has rectified fume problems and reduced cabin noise.
Richard operates the starter and the big radial rumbles into life. He reaches forwards to the control knob on the left side of the floor, just in front of the trim lever and unlocks the tailwheel for taxiing. There are no flaps to worry about with the huge wing and conglomerate of wing and undercarriage struts providing plenty of drag. We make our stately way to the runway, with a lot of S-turning on the way.
Following a last switch from side to side to ensure that the runway ahead is clear, he runs straight for a moment, locks the tailwheel and slowly pushes forwards the throttle lever. All throttle movements must be slow with this 80-year-old engine.RATTLES AND SMELLS
The vibrations, rattles, smells and strange sounds intensify and the rpm gauge rises slowly to 1,800rpm, its needle quivering slightly. Meanwhile the aeroplane starts to move forwards. I can feel Richard using rudder to keep us straight. The tail rises pretty much by itself – I have my hand lightly holding the rear joystick and it seems barely to move. At 50mph and after a 500ft run (on tarmac) the Curtiss Robin just levitates into the Georgia skies.
Richard tells me over the (modern, but you have to have it) intercom that I have control and I start to gently use that big stick, pulling back slightly as the speed increases and the Curtiss Robin climbs at about 70mph and 500fpm, with 1,900rpm indicating on the tachometer, not quite up to the 640fpm quoted in the 1920’s sales literature.
At Richard’s suggestion I level off at 1000ft. In the still morning air, in our wicker-and-cushion-seat carriage, this is the best place to observe the fields, houses, lakes and woods shrouded in misty morning haze, as they drift by beneath us.
The sales literature says the best cruising speed is 102mph. Richard prefers a slower
75 to 85mph with between 1,700 and 1,800rpm indicated. At these settings, fuel consumption is 12usg an hour, giving an endurance of four hours.
How can I describe the feeling of cruising in this aircraft? There’s not much of a view over the nose with those rocker heads in the way. Then there is the vibration, caused by the engine being bolted directly to the steel tube airframe without any rubber damping. Richard has had the prop re-balanced and he assured me it was now much smoother than it had been.
To adjust the elevator trim you move the handbrake type lever on the left of the cockpit which engages in holes in a quadrant. In still air you really can trim out quite well but nowhere near as successfully as you can in a modern light single. You always have to use the stick and fly the aeroplane, the slightest air disturbance affecting that large wing. Any manoeuvres have to be at the Curtiss Robin’s pace. You can’t rush Poacher’s Pony.
When leading into a turn you must use rudder, following with the stick and you must be ready to follow with some opposite rudder to prevent the aircraft from tightening up on the initial rudder input.
It takes strong arms and legs to ensure these manoeuvres are all well coordinated and on a long trip, with wind as an added factor, Richard’s ‘two-hour limit’ for cruising legs is understandable. That said, slow, ambling turns are what the Curtiss Robin handles best – the last time anyone tried a fast turn was during test flying in 1928!
The big wing is quite happy at 60mph in a 30 degree banked turn as we discovered during the air-to-air photo sortie. Set up the turn and bank angle with application of power to suit and the Curtiss Robin will saunter around in wide circles quite easily. If you want to lose height then the classic sideslip is what these 1920’s designs excel at and this makes an extremely efficient way of dropping to a lower altitude without increasing speed. The sink rate can be dramatic, so is best not advised on short finals to land.
I can see that you do have to be ahead of the game during landing, but even in a stiff wind (as long as there’s not more than a 30-degree crosswind), the Curtiss Robin will perform gracefully. You also require plenty of muscle to keep control in strong winds, but it’s here that the elevator trim is particularly useful. The ample rudder also helps.
Downwind, we set 75mph, then reduce power and revs to about 1450rpm, an indicated descent rate of 500fpm showing on the VSI. Flying the base, finals and short finals fairly tightly at 60 to 65mph you hold the Curtiss Robin off, pull the throttle back to idle and the big wheels seem to reach out and you settle gently onto the runway. A three-pointer is the accepted best landing technique for this gentle giant.
The ground roll is minimal, particularly on grass, with no need for brakes – all you must remember is to reach down and unlock the tailwheel, then add some power and a little brake/rudder input. I tell Richard that the Curtiss Robin seems like quite an easy aeroplane to land, given its vintage. He agrees, and puts it down to the very wide track undercarriage – eight foot – but points out that we’ve been flying in ideal conditions. “It’s a different story on a windy day,” he says, and adds, “but we don’t fly her too much when it’s windy”.