Drawing - Paul Matt - Waterman Arrowbile

The Waterman Arrowbile was a tailless, two-seat, single-engine aircraft that used a pusher-power configuration. It was intended to be roadable aircraft. It was built in the U.S. in the late 1930s.

In May 1935 Waterman made a submission to the government funded Vidal Safety Airplane competition. It was for the Arrowplane, sometimes known as the W-4. It had a strut-braced high wing on a blunt-nosed, narrow fuselage pod, with a tricycle undercarriage. Its wings had wooden spars and metal ribs and was fabric covered, with triangular endplate fins carrying upright rudders. The fuselage was steel framed and aluminum covered. It was powered by a 95 hp (71 kW) inverted inline four-cylinder Menasco B-4 Pirate pusher engine, which was mounted high in the fuselage’s rear.

The Arrowplane was not intended for production or to be roadable, but its success in the Vidal competition encouraged Waterman to form the Waterman Arrowplane Co. in 1935. The resulting Arrowbile, referred to by Waterman as the W-5, was similar both structurally and aerodynamically to the Arrowplane, though the fins differed in shape, with rounded leading edges and swept-back rudder hinges. To make it roadable the wings and propeller could be quickly detached. The engine was water-cooled as per most car type. Waterman modified a six-cylinder upright, 100 hp (75 kW) Studebaker engine. It was placed low in the pod, with the propeller shaft being driven by six ganged V-belts with a 1.94:1 reduction. The radiator was in the forward fuselage, fed from a duct opening in the extreme upper nose. On the ground the engine drove the main wheels through a differential gear and the car was steered by its nose-wheel. The wheels were enclosed in fairings. Instead of removing the propeller for the road, it could be de-clutched to prevent it windmilling.

The wheel in the two-seat cabin controlled the Arrowbile on the road and in the air. The wing’s elevons moved together to alter pitch and differentially to bank. The rudders, interconnected with the elevons when the wheel was turned and moved only outwards. The raked rudder hinge of the Arrowbile provided the banking component even from a nose-down attitude. There were no conventional flaps or wing mounted airbrakes but the rudders could be operated as brakes by opening them outwards together with a control independent of the wheel.

The Arrowbile first flew on February 21, 1937. Studebaker was interested in the Arrowbile because of the use of their engine and ordered five. The third Arrowbile was the first of this order. However there was little market response and the line was halted in 1938, with no more production aircraft completed. Note, the fourth Aerobile was completed as a conventional, non-roadable aircraft; Waterman initially retained the Studebaker engine but in 1941 replaced it with an air-cooled 120 hp (89 kW) Franklin. In 1943 he modified the wings with slotted flaps and later still replaced the braced wing with a cantilever one, using the wing from the unbuilt fifth aircraft.

The last, sixth aircraft was not completed and flown until May 1957. It was a three-seat, roadable version powered by a water-cooled 120 hp (89 kW) Tucker-Franklin. It was cooled by radiators on each side of the engine, fed air by fuselage side scoops. In the absence of the forward radiator the nose was remodelled, becoming shorter and blunter. The fins were also altered so that the upper and lower leading edges met at an acute angle. At some point this particular Arrowbile was renamed the Aerobile, though it was not a name that Waterman used.

Specifications

• Capacity: Two
• Length: 19 ft 4 in. (5.89 m)
• Wingspan: 38 ft 0 in. (11.58 m)
• Empty weight: 1,941 lb (880 kg)
• Gross weight: 2,500 lb (1,134 kg)
• Fuel capacity: 25 US gal (21 Imp gal; 95 L)
• Powerplant: Studebaker-Waterman 6-cylinder inline, water-cooled, 100 hp (75 kW)
• Max airspeed: 120 mph (193 km/h; 104 kn)
• Cruise airspeed: 102 mph (89 kn; 164 km/h)
• Range: 350 mi (304 nmi; 563 km)
• Rate of climb: 600 ft/min (3.0 m/s)
• Landing speed: 45 mph (72 km/h; 39 kn)
• Max road speed: approximately 70 mph (113 km/h)

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