Yackey Monoplane

The Yackey monoplane had a parasol wing built around two spruce box spars with plywood skinning ahead of the forward spar. It used the popular Clark Y airfoil and had a constant chord with blunt tips. It was braced to the fuselage on pairs of parallel struts to the lower fuselage longerons, and a central, short inverted vee cabane to the top of the fuselage.[1]

It was powered by a 225 hp (168 kW) Wright Whirlwind J-5 9-cylinder radial mounted in the nose with its cylinders exposed for cooling. The fuselage was flat-sided apart from raised upper decking.[1] Both the cockpits were open, with the two passengers[2] placed side-by-side over the wing with entry via full-depth doors. The pilot sat just aft of the wing trailing edge, where a cut-out provided a wider upper field of view. Baggage or mail was placed in a large hold behind the pilot. Its fuselage tapered rearwards to a cropped-triangular fin with a comma profile, balanced rudder. The tailplane was semi-elliptical in plan and mounted on top of the fuselage, each side braced from below with a strut and a parallel wire and from above with a wire to the fin. Elevators were full and rounded, with a large gap between them for rudder movement.[1]

The Yaxley had fixed, conventional landing gear with large wheels, each fitted with brakes and on half-axles mounted on the lower fuselage longerons. Short, vertical legs were mounted on the forward wing struts which were reinforced at those points by diagonal struts to the wing centre-section. Drag struts sloped upwards to the root of the rear wing strut. Its spring-steel tailskid was steerable.[1]

The two prototypes took part in the 1927 National Air Derby, a 24 hour race between New York and Spokane.[1] One, piloted by Hamilton Lee, gained fifth place and a $500 prize.[3]

By October 1927 Yackey had rebuilt and reorganized his two factories for serial production at an initial rate of one in three weeks, moving to one a week at the start of 1928. They had firm orders for five.[1] However, these plans were abandoned after 4th October when Yackey died making a final test flight of a Monoplane before handing it over to its new owner. A newly reinforced wing bracing failed during the programme of aerobatics he routinely used in a final, personal test of all his aircraft.[4][5]

Data from Aero Digest 1927[1], [6]

General characteristics

• Crew: One
• Capacity: Two passengers
• Length: 26 ft 2 in (7.98 m)
• Wingspan: 41 ft 2 in (12.55 m)
• Height: 8 ft 4 in (2.54 m)
• Wing area: 284 sq ft (26.4 m²)
• Airfoil: Clark Y
• Empty weight: 1,460 lb (662 kg) 2460
• Fuel capacity: 84 US gal (70 imp gal; 320 l)
• Payload: 1,000 lb (450 kg)
• Powerplant: 1 × Wright J-5 Whirlwind 9-cylinder air-cooled radial piston engine, 225 hp (168 kW)
• Propellers: 2-bladed Standard Steel

Performance

• Maximum speed: 140 mph (230 km/h, 120 kn)
• Cruise speed: 115 mph (185 km/h, 100 kn) at 1,600 rpm
• Stall speed: 40 mph (64 km/h, 35 kn)
• Landing speed: 40 mph (64 km/h; 35 kn)