FLIGHT TEST

Up with the Cloudster…

Clive Davidson clearly experiences the delights of the Rearwin Cloudster – a vintage radial… Pictures by Neil Wilson.

Above The

Cloudster flies over the moored fleet of cruise liners on the south coast, the sun glinting on its leading edges and prop.

Flight Test

It doesn’t do justice to sit in an aircraft and pretend to fly. We all know that aircraft are living, breathing, mobile pieces of aerial art which transport us both physically from place to place and (excuse the pun) to another ‘plane’ of consciousness. But, just occasionally, it does no harm at all to sit in a familiar cockpit and go through a couple of drills and scenarios. It’s not a pretence, it’s preparation, as I was again very fortunate to be offered the opportunity to fly Will

Gray’s ‘polished-to-showroom’ condition, Rearwin Cloudster.

Notably, when opening a door to pull yourself up and in, with the aid of a strap, you are greeted by the evocative and enticingly deep and satisfying aroma of leather. Gorgeous. Rearwin Airplanes was founded in 1929 after its founder,

Andrew ‘Rae’ Rearwin, a successful entrepreneur with no previous involvement in aviation who, having looked at what existing companies were building, decided he could build something better. Unable to buy out an existing company, he set up in an old workshop in Salinas, Kansas with his teenage sons, Ken and Royce, plus an aeronautical engineer, to build a prototype. This first machine, the Rearwin Ken-Royce, a threeseat sport biplane powered by a six-cylinder, double row 180hp Curtiss Challenger radial engine, was completed in early 1929 and competed in a number of air races to drum up publicity. Meanwhile, Rearwin succeeded in finding a financial partner and set up Rearwin Airplanes at Fairfax

Airport, in Kansas City. By the beginning of the 1930s the Great Depression was starting to bite, and aircraft companies were turning to low-cost, low-powered, ultralight two-seaters in an effort to maintain sales and stay in business. Rearwin bought such a design from a neighbouring company on the airfield, a high-wing tandem two-seater, employed the two designers and completed the prototype of what became the Rearwin

Junior, which first flew in 1931. The company sold seven

Ken-Royces and 30 of the ultralight Rearwin Juniors, most of which were powered by the Dutch-built 45hp three-cylinder

Szekely SR-3 radial, but orders soon dried up and, in 1933,

Rearwin reorganised the company with himself as sole owner, renaming it Rearwin Aircraft. The company then built two new designs, the Speedster, which was a high performance, high-wing tandem, and the more appealing and lower cost Sportster, the latter being powered by LeBlond radials of 70-90hp, and the 90hp

Warner Scarab. In all, around 270 Sportsters were built, so the company was on the up. Rearwin acquired the LeBlond Aircraft Engine Corporation in 1937 and had yet another change of name, this time to

Rearwin Aircraft & Engines, with LeBlond becoming its

Ken-Royce engine division. In 1939 they introduced their first side-by-side seat aircraft, the Model 8125 Cloudster, powered by the now

‘Ken-Royce’ 7F 120hp radial, a year later adding the Model 8135 with a sideways-facing third seat. Legendary Pan

American Airways founder Juan Trippe, who owned a

Rearwin Sportster, approached Rearwin in 1941 to develop an instrument trainer, and the Model 8135 was modified to become the 8135T. It reverted to tandem seating and introduced jettisonable doors for both the instructor and student pilot, and seats with removable cushions to accommodate backpack or seat parachutes. The student sat in the rear with their own controls and a removable instrument panel, and blackout curtains could be fitted around the student for instrument training, allowing the instructor to maintain normal visibility in the front seat. In all, 125 Rearwin Cloudsters were built, 25 of them 8135T instrument trainers. Rearwin’s final aircraft was the SkyRanger, which flew in 1940 and featured the small flat four Continental and Franklin 65hp and 90hp engines. Unlike its contemporaries, principally the Piper Cub, it did not secure military interest as a primary trainer with the huge orders that endowed it, it was considered too challenging to fly so, with only 82 produced, in 1942 production ceased. Rae Rearwin sold the company that same year and it became Commonwealth Aircraft. It survived the war years thanks to government contracts, including building 1,470 Waco CG-4A military troop gliders, but when it re-introduced the Skyranger in 1946 it failed to secure sufficient orders. The company declared bankruptcy in 1946 and closed its doors for good in 1947.

Our test aeroplane

Will’s Cloudster, G-EVLE, is an early two seat 8125 model, built in 1939. It was imported into the UK because the buyer wanted its Warner Scarab engine to fit into a WWI replica, the original of which would have been fitted with a le Rhone rotary. Melvyn Hiscock bought the aircraft less engine in 1994 and restored it to its current beautiful condition, sourcing a replacement 145hp Warner Scarab 145, an engine that the type was not fitted with at the factory. Melvin, who was also passionate about playing and building guitars, penned the book Make Your Own Electric Guitar in 1986 and was working on a third update when he sadly died in February after a long battle with cancer. Melvyn was also a published author in aviation, he worked with the Memorial Flight Association in France, building and rebuilding airworthy WWI aircraft, producing Classic Aircraft of World War One in 1994, and Hawker Hurricane, Inside and Out in 2003. Unfortunately, I was not privileged to have known Melvyn, but people tell me he was a naturally funny and all-round good chap. His spirit no doubt lives on in the countless home-crafted bedroom guitars of budding Van Halens, and most certainly in this wonderful aeroplane, on which he lavished so much attention. Will acquired the aircraft from Melvyn in 2015.

First impressions

On meeting the Rearwin Cloudster for the first time you are facing a high-wing, tailwheel aircraft with a radial engine which has, to put it mildly, substantial presence. Its size, colour and condition lend sheer admiration for a machine that has not only a visual impact but all the charms and rumble of a slow, low revving radial engine. The fabric-covered fuselage frame is of metal tube, and

Above You cannot fail to be moved by the sheer presence of this big old snub-nosed radial. It is a piece of pure artistry.

Left Will Gray adds scale to the Cloudster; it’s a big aeroplane.

the wings and differential ailerons are wooden structures, again covered with fabric. It strikes me that the ailerons are rather long, being about two thirds of the span – of course, flaps were not particularly de rigueur on light aircraft in the late 1930s. The outward ends of the wings are curved, with protruding navigation lights and are strut and jury braced. In sailing terms, the fuselage has a lot of ‘windage’, with the flat-sided fuselage area aft of the centre of gravity being quite substantial. However, the fin is reassuringly enormous, and more than hints at an aircraft that has positive directional stability. The rudder is, by contrast, quite small in area and is vertically hinged with no aerodynamic balance. However, despite its seemingly small area it is positioned correctly for spin recovery when the upward, diagonal airflow over the fin would stream directly and effectively onto a correcting rudder, this flow being forward of an otherwise masking tailplane. Unfortunately for me, but to Will’s relief, there is a cockpit placard preventing us from checking its effectiveness, which reads: No inadvertent spinning! There is a die-straight, ground-adjustable rudder trim tab with no sign of it ever needing to be bent to improve an out of trim rig. The elevators have aerodynamic balances forward of the hinge line to help lighten the pilot’s stick forces in pitch, the right elevator having a trailing, piano hinged, reinforced trim tab. There are hand-hold cut outs inboard of the tailplane’s leading edge as an aid to ground handling. The tailplane and fin are braced with diagonal stainless wires and, crouching down by the rear left tail, under the tailplane, there is an inspection panel so that the twin mode, castering/steerable pneumatic tailwheel assembly may be checked and, if needed, adjusted. Its frame has holes for the lugs of a towing arm either side. Standing behind the tailplane and looking forward along the fuselage, the fabric strips run back up to the two skylights, and the wing to fuselage fairings are nicely sealed down their edges. There are wing-mounted fuel tanks at the inboard section of each wing, each holding 17 imperial gallons. Returning forward, I only have to dip slightly under the trailing edge to avoid knocking my forehead. And the underwing fuel drains are sensibly positioned further out than the opening of the doors, so there is, thankfully, little chance of an inadvertent pate scrape. The wings’ leading edges are above head height.

Bottom Beautifully trimmed in red leather, the baggage bay incorporated a third, sideways facing seat in the later 8135 model.

Below Fabriccovered steel tube empennage with that substantial fin. Note streamlined wire bracing and nice ‘built-in’ rudder trim tab.

The cutting edge

The prop is a lightly toned wooden Sensenich, with metal leading edges, smooth multi-layered scarfed contour lines leading outwards to khaki green tips, it just has to have a hand run over its length in an appreciative gesture (yes, the mags were definitely off). The blades are sitting, perhaps ‘resting’ might be more appropriate for this grand old dame, on the horizontal at the three and nine o’clock positions and directly behind is the Warner Scarab’s grey painted crankcase, with its one to seven numbered cylinders, running anti-clockwise as we look at it. The front set of spark plugs have their leads protruding just slightly forward of the circular cowling before curving back, being tucked in and back to a magneto. The rear set of plugs cannot be seen.

Health warning

Being a radial engine, there is an outside chance that oil may trickle down internally and possibly drain into the lower cylinders, in our case numbers four and five. If this was not detected and drained prior to an attempted start, damage to the conrods is the – very expensive – likely result. One of the pre-, pre-starting checks of any and all radial engines is to pull through the blades in the standard direction of rotation. Most, like ours today, would be pulled through anti-clockwise with the left hand, which enables the pilot to mentally anticipate using right rudder to counter any power induced swing on take-off, or induced yaw through power application. It will seem odd, but the position of the prop will be different as each compression is felt. Should any undue

Left Big doors with sliding windows and straps by the door pillar, to haul yourself up and in. Note rearward facing step.

Below Lovely classic cockpit with many period instruments and switches. The compact radio and transponder do not overtly intrude. resistance or untoward pressure be felt while attempting to move the propeller, don’t try to force it, stop and investigate by removing a lower cylinder spark plug. Do not, under any circumstances, mistakenly now turn the prop’ backwards. Yes, it will turn, and the offending oil will disappear, removing the awkwardness. But that dark cold goo has only disappeared for a short while, back up the inlet tube and, should you turn the prop or attempt a start, then that bitter, ‘bible black’ oil is going to ruin your day. Which brings us nicely to the oil filler neck and dipstick, which is on the upper curvature of the rear section of the cowling. A long rectangular air filter sits beneath the engine and twin matching open exhausts protrude from either side of the cowl. A finger rubbed inside one reveals the previous pilot (which just might have been me) may not have leaned the mixture in the cruise, as I now have a sooty finger. A rather art deco-like generator is mounted centrally on the lower main undercarriage arms, the highly cambered silver prop blades rotating freely with a spin from that same sooty finger. To the left of it is the larger of the two venturis, the other being just in front of the P1 door, both certainly benefitting from prop blast.

Up and in…

Getting up and into the cockpit is helped by a step attached beneath the low junction of the sloping, angled wing struts and fuselage, pointing backwards and not outwards… which has to be remembered when getting out and your foot is waggling around trying to find a contact. There’s a helpfully placed high internal leather grab strap to pull yourself in (rather than using one of the diagonal braces above the panel), while the other hand supports your inward leaning body on the seat. Head down and rising into the cockpit the right leg has to be brought up and through, squeezed between the seat and the other limb to be placed beyond the floor mounted stick. The caramel-coloured headliner, black instrument panel, red framed doors and dark floor, along with the surrounding plush red leather upholstery, add to the very pleasant decor and surroundings. I could get used to this level of comfort. Looking down, the sticks rise from the floor and are curved towards the pilots, just as if swiped from a helicopter. It still has a full throw of movement even if the seats are slid on their rails as far forward as they might go. The floor’s metal heel

plates appear not to have a mark on them with not a scratch of wear. The rudder pedals sprout through the wooden floor and the left-hand set has efficient circular heel activated pedals for the hydraulically operated brakes.

The view

Scanning outwards, clockwise and from the tail, I do not have to drop my head as much as I might from, say, an Auster, in order to see under the top of the window frame. The nose, of course, circular and with its outward radiating cylinders, cowled for aesthetics, aerodynamics and cooling, will block some of the area ahead, particularly the opposite side to whichever seat you peer from. A conscientious pilot will be S turning when taxying, clearing the way ahead (and a very good reason to bring along, not just a sociable friend but another set of observant eyes). I know of a flying friend, poor fellow, sitting in the standard left-hand P1 seat of his quite large taildragger who, after completing his pre-take off checks pulled forward and unfortunately turned around to admonish his distracting and noisy children in the back seat. His unguarded and difficult to see right wing tip was lacerated to narrow shredded slivers of metal by the prop of an unseen stationary aircraft. Ouch!

Panel and facilities

The wing tanks’ contents gauges are set back in the wing roots and are straight from a Model A Ford, both indicating full, the arrowhead-shaped fuel selector being on the panel right in front of the P1 seat. My other bête noire, the headset jacks, on vintage aircraft upgraded with comms when originally manufactured without, can literally be hidden anywhere. But that was quickly solved today as they are handily placed between the seats. The 8.33 Trig radio is on the right-hand side of the instrument panel and a TRT 800H mode S transponder is on the left. There is a period, and rather chunky, artificial horizon that protrudes from the centre of the panel, and to its left and down are a turn and slip indicator, a VSI, an altimeter, an ASI in MPH and a rpm gauge. The Ki-gas primer may be operated by the pilot’s left hand as it is positioned on the extreme left, close to the fuel selector. The right hand can handle the large black centrally mounted throttle, with the carb heat to its left and red mixture knob to the right. The circular mag switch and the now unusual ‘advance/retard’ knob are higher up to the right. The starter and its red warning light is back on the left, by the fuel selector. Low and to the right of the carb heat, throttle and mixture are the three small engine condition dials of oil temperature, oil pressure and CHT, all with coloured operational arcs. Beyond these are the circuit breakers with the Master furthest to the right. Oh, I almost forgot, the park brake is by the fuel selector – depress the heel brakes, pull the lever out for on… To release them you push it in and then press the brakes, pretty similar to the Cessna 150. The elevator trimmer is the car type window winder handle mounted on the ceiling between the skylights. I have to admit, this arrangement always catches me unawares at the first few attempts, but as the gearing gives good feedback it soon becomes obvious with pressure on the stick either increasing or reducing. Having given the handle and dial, with its pointer, a good scan, I have a much better understanding of it. Craning back to read the small letters on the indicator rotating the handle anti-clockwise raises the nose and vice versa. The ‘landing’ position has the pointer at 10 o’clock and ‘take-off’ at five o’clock. It’s a shame that the elevator trimmer is positioned on the right elevator and the pilot sits on the left and is unable to see it. However, the trimmer is there to be used and the take-off technique takes advantage of this.

Above It may not be fast or efficient, but it lopes along with an impressive ease. A cliché perhaps, but it really is a ‘gentleman’s carriage’ Fuel and spark, start…

It has already been mentioned that any radial engine should always be pulled through when cold, and the Scarab benefits from this care. Magnetos should of course be checked ‘off’ and the prop pulled through at least four revolutions (that means eight blades pulled and not just four compressions). The fuel selector is then turned to the ‘Both Tanks’ position, so the pointer is upwards at 12:00, and the red mixture lever is in for fully rich. Check magnetos are off and the throttle is virtually closed. And now the unusual bit, the Advance/Retard knob is pulled fully out to retard the ignition. We then prime from cold four or five pumps on the ki-gas primer. Ready? Clear? Master on. Press the start button with your left hand for four of five clockwise blades, and lean over to flip the mags on with the right hand. The engine doesn’t hang about and fires almost immediately, so promptly push the Retard button in to advance the timing. Your actions now are accompanied by a gloriously languid 1-3-5-7-2-4-6 firing rumble of an awakening Scarab at 400rpm. Sonic heaven! But we have work to do, check and keep an eye on those small oil dials for pressure and a slow but steady rise of temperatures into the green arcs of good health. The revs can be brought up to 1,000, radio turned on with the home frequency displayed, and the intercom also turned on... and adjusted. When warmed, taxied and brought to the hold with clearing sweeps of the nose, we can go through the power checks – mags and carb heat check has the throttle advanced to 1,700 rpm against the parking brake and the stick held right back. It’s a stirring sound of prop and power, the calm of going back to idle at 400rpm is but a sigh. Pre-take-off checks complete, ensuring the trimmer is set for take-off, turn to make sure the final approach path is not masked by a high-wing, self-brief for emergencies, and

our call ready for departure is answered with the confirmation ‘there is no known traffic’. The wind is slight and helpfully from the right, the same side rudder will be needed as she will want to weathercock, and we are going to stay straight as we accelerate. To be honest there is little gyro effect as the tail need not be raised during the take-off roll. It’s a question of the wing’s incidence being less than its stalling angle when sitting on the ground and having sufficient power to rise from the ground in a three-point attitude. The rotate speed is quoted at 54mph, but that does not fit any tailwheel aircraft technique that allows the aircraft to fly itself off from other than the ideal wing to air presented attitude. It is just nosewheel jobs with a flat sitting position that need a rotation to break ground. Book figures show an unfactored take-off roll for us is 665ft, and we reach the distance and speed promptly. Our optimum climb speed is 80mph and easing the stick forward from leaving the ground to accelerate in ground effect, helps the needle on the ASI quickly reach that speed. Climbing out at 80mph gave us a 1,000ft height gain in 75 seconds. That’s a very respectable 800ft per minute. The cruise attitude is at 100mph and I can almost count the blades as they swing by. The trim handle can be wound clockwise, any stick pressure negated to hold that big round nose below the horizon. We are rumbling along with 1,700rpm, 70% power, that’s near the profundo operating speed bands of a Gipsy Major, but way, way under the soprano range of the Rotax. Scarab’s sonorous rhythm is a good steady reliable beat. The view ahead is good and consumption is in the order of 30 litres per hour and all is great with the world. Textbook numbers are 145hp at 2,050rpm at mean sea level. This 100% power returns 118mph. Vne is 170mph.

Stable

The control forces are not high, with no slack caused by any wire stretch and when moving into, out of and adjusting position alongside Patrick’s Freelance, so that Neil could get images of Will smiling, Lima Echo responded well. I asked Will if he was comfortable being so close to another aircraft, as we both stared at the Freelance while being beckoned closer. “Oh yes. But, never from this side.” “Oh?” says I. Will replied, “I used to fly my Bonza (Beechcraft Bonanza) with the door off, out of Duxford with Squadrons of Spitfires around and behind, for a notable aviation photographer to take his snaps.” Not only that, but he and his wife Wendy have flown themselves around the world – an experienced fellow indeed.

Return to base

Upon being cleared to break away I ran through the stability exercises, the up and down of the returning phugoids, and crossing and releasing either the stick or rudder pedals in turn from steady heading side slips to prove she was, indeed, a stable girl without any deviating foibles in all three dimensions. Her pendulous stability also shone through in the standard stall, when she eventually had had enough of having her throttle closed, in sync with a speed loss of one mph per second and height maintained with an ever so slightly increasing nose brought up to the horizon. When eventually she decided to make a slight departure from controlled flight, the right wing dipped slightly. I had previously recorded a 10 degree drop. The vocabulary on the form asks for angle of wing drop and these standard words quantify an aerodynamic ‘fall’. The wing’s action is more akin to a dip and today it was less at eight degrees. And with a low fluctuating airspeed of 40mph, in tune with a slight tail buffet felt before the stall proper, that being just a mush with no wayward directional rudder correcting inputs to remain wings straight and level. The standard stall recovery of stick forward, power and balancing rudder to prevent an unwanted yaw, works emphatically well. This all speaks well should any go-around from low speed be needed from a baulked landing.

Above That lovely seven-cylinder Warner Scarab 145 and retro styled Sensenich wooden propeller. Note, air-driven generator nicely incorporated in undercarriage structure. Back in the circuit

I flew a left-hand curved approach, so as to improve my view of the threshold. This isn’t particularly necessary but being familiar with the machine it is a method I enjoy, reducing speed and judging height diminishing and the projected roll out point. Equally so, there comes a point where the last bit has the wings level just as a straight in from 400-500ft allows for simply assessed corrections. If there is any trick it is to think ahead and be straight as we touch in the three-point attitude, having held off. Approach is at 80mph, carrying a little power and, upon landing with a ‘squib squib’ from the tyres, make sure your heels are ready to jab a brake to keep straight. Book figures are a landing roll of 795ft. I have to admit to a slight pause on each occasion of remaining still on the runway before opening up the Scarab to roll to and take the turn for the taxiway. The reason, well, it’s a lovely machine that contrasts the types I am fortunate to fly, I so enjoy the rumbling chat of those radial cylinders. Thank you, Will, for another wonderful flight. ■

Specifications Standard 8125 Rearwin Cloudster

General characteristics Crew: One pilot Capacity: One passenger Length: 21ft 6in (6.55m) Wingspan: 34ft 2in (10.41m) Height: 7ft 4in (2.23m) Wing area: 162 sq ft (15.0 m2) Empty weight: 1,140lb (520kg) Gross weight: 1,900lb (860kg) Powerplant: 1 × Ken-Royce 7G, 125hp (93kW)

Performance Maximum speed: 135mph (216km/h, 117kn) Range: 600mi (960km, 520nm) Service ceiling: 16,000ft (4,900m) Rate of climb: 860ft/min (4.4m/s)