Single seat single engined biplane with conventional three axis control. Wing has unswept leading and trailing edges, and constant chord; conventional tall. Pitch control by elevator on tail; yaw control by fin mounted rudder; roll control by full span ailerons on upper wing; control inputs through stick for pitch/roll and pedals for yaw. Wing braced by struts and transverse X cables; wing profile; double surface. Undercarriage has three wheels in tail dragger formation. Push right go right tailwheel steering connected to yaw control. Aluminium tube framework, without pod. Engine mounted between wings driving tractor propeller. Tubing from 6061T6 aluminium; galvanised steel rigging; Dacron wing covering.
This three axis machine is a biplane which was revealed to the public at the EAA convention for amateur constructors, Oshkosh, in August 1982, where it was hailed as a modernised version of the Whing Ding II with a simpler structure and more power. The adoption of an aluminium tubular structure allowed Aircraft Specialties to offer the Delta Bird in plan form, as with the other two aircraft, but also as a kit requiring around 200 h for assembly. In place of the pusher common to the Beta Bird and the Whing Ding II, the motor is mounted as a tractor on a triangular framework at the front of the main framework. The exhaust pipe passes under this triangular section and finishes by the junction of the two triangular frameworks which support the main wheels, an arrangement designed to allow all terrain use. The machine retains conventional controls with ailerons on the trailing edges of the two top wings, a rudder hinging from the fin and the elevators from the horizontal stabiliser; they are all of generous proportions.
Engine: Cuyuna 430R, 30 hp at 5500 rpm.
Propeller diameter and pitch 54 x 27 inch, 1.37 x 0.69 m.
Belt reduction, ratio 2.0/1.
Power per unit area 0.20 hp/sq.ft, 2.1 hp/sq.m.
Fuel capacity 3.5 US gal, 2.9 Imp gal, 13.2 litre.
Length overall 15.0 ft, 4.57 m.
Height overall 6.0ft, 1.83m.
Wing span 24.0ft, 7.31m.
Constant chord 3.5 ft, 1.07 m.
Sweepback 0 deg.
Tailplane span 8.0 ft, 2.44 m.
Fin height 3.7 ft, 1.13 m.
Total wing area 152 sq.ft, 14.1 sq.m.
Fin area 9.0 sq.ft, 0.84sq.m .
Tailplane area 20.0 sq.ft, 1.86 sq.m.
Wing aspect ratio 6.9/1.
Wheel track 6.3ft, 1.92 m.
Main wheels diameter overall 15 inch, 39 cm.
Empty weight 218 lb, 99kg.
Max take off weight 450 lb, 204kg.
Payload 232 lb, 105 kg.
Max wing loading 2.96 lb/sq.ft, 14.5 kg/sq.m.
Max power loading 15.0 lb/hp, 6.8kg/hp.
Load factors +3.5, 3.5 design; +5.3, 5.3 ulti¬mate.
Max level speed 60mph, 97kph.
Never exceed speed 60mph, 97kph.
Max cruising speed 45mph, 72kph.
Stalling speed 26 mph, 42 kph.
Max climb rate at sea level 400 ft/min, 2.0 m/s.
Best glide ratio with power off 6/1.
Take off distance 250 ft, 75 m.
Landing distance 250 ft, 75 m.
Range at average cruising speed 50 mile, 80km.
