Cranwell Production

A single-engined two-seat biplane built as an entrant to the Lympne Two Seater Light Aeroplane Trials of 1924. It was a single bay sesquiplane the lower wing having an area only 52% of the upper one. As a result of the different spans, the interplane struts leant strongly outwards. The interplane gap was unusually large, with the aim of reducing interference effects between the wings. The wings were of conventional construction, with I-section spruce spars, and lacked stagger and sweep; both had constant chord and ailerons were carried on both wings, with their own internal control runs. The CL.2 was a two-seater (with dual controls as required by the Lympne competition rules) with pilot and pupil sitting side by side under the forward part of the upper wing, and as a result the fuselage was broad at this point, broader than it was deep. Another consequence was that the centre section struts from the upper wing to the fuselage top longerons were unusually widely spaced, a spacing enhanced by a slight outward lean. The wings did not fold but could be rapidly removed for transport.
The fuselage was flat-sided wood girder structure, with wire bracing, built up around four longerons which were made of spruce at the rear and ash forward of the cockpit. Behind the cockpit, the fuselage narrowed in plan view in a gently curved way to the tail, whilst in elevation the upper longeron was horizontal with the aircraft in flying position, the lower one was angled upwards. The fin and rudder formed an approximate quadrant, though the unbalanced rudder extended down between the elevators to the fuselage bottom. The nearly rectangular tailplane was mounted on the upper longeron. A standard curved decking, built up with stringers over frames topped the fuselage from front to rear. Forward of the cockpit the lower longerons curved strongly upwards and inwards, meeting the now inward curving upper members at the engine bulkhead. The single axle undercarriage was mounted on a pair of short V-shaped legs, each V cut out of plywood and mounted vertically on the lower longerons. The CLA.2 sat close to the ground, with its wheels only slightly ahead of and below the wing leading edge. One 32 h.p. Bristol Cherub I flat-twin driving a two-bladed small diameter propeller.

Specification
Span	Length	Height	Wing Area	Empty Wt	Max AUW	Cruise Speed	Maximum Speed	Range	Service Ceiling
29 ft 8 in	23 ft 3 in		223.5 sq ft	540 lb	897 lb		62.5 mph/ 54 kn
9.04 m	7.09 m		20.76 m2	245 kg	407 kg		101 kph

A parasol winged single-engined, single-seat British aircraft built to compete in the Lympne air races of 1925. The wings of the CLA.3 were straight and had constant chord apart from at the rounded tips. The wings were built on two I-section spruce spars and fabric covered everywhere apart from at the leading edge, where thin aluminium was used. Differential ailerons were fitted; initially the gap between aileron and wing was filled with narrow rubber flaps, but later they were removed as they added weight and made lateral control heavy. The wings were held about 7 in above the fuselage, parasol fashion, by two steel lift struts on each side which ran from a common point on the lower longeron of the fuselage to the front and rear spars at mid-span. Three vertical steel cabane struts on each side joined the centre section to the upper longerons.
The rear part of the fuselage was a Warren girder based on four longerons, tapering towards the tail. The fuselage cross section was kept to a minimum to reduce drag and to this end the pilot sat on the cockpit floor. In front of the pilot the structure was wire braced, the longerons converging to become overhung engine bearers, engine being mounted on a plate with a fireproof bulkhead, within a long, smooth aluminium cowling blended into the spinner of the two-bladed propeller, with the engines's cylinder heads were exposed for cooling. A rounded decking, built up with stringers in the usual way, topped the fuselage from propeller to stern and contained the 4.5 imp gal tank immediately in front of the cockpit, high enough above the engine to allow it to be gravity fed. The overall fin plus rudder shape was not unlike the de Havilland form, though the rudder was not balanced. The tailplane had a straight leading edge inboard, then curved; it could be adjusted in incidence on the ground but not in the air. The divided elevators were unbalanced. The undercarriage was a simple single axle design using rubber shock absorbers, with the main legs attached to the lower longerons at the same points as the lift struts and braced to the most forward fuselage frame. It was completed with a tail skid. One geared 32 h.p. Bristol Cherub II powerplant driving a two-bladed propeller, later replaced by a direct drive 36 h.p. Cherub III, fitted with a metal propeller.

Specification
Span	Length	Height	Wing Area	Empty Wt	Max AUW	Cruise Speed	Maximum Speed	Range	Service Ceiling
21 ft	18 ft 7 in	6 ft 10 in	70 sq ft	325 lb	530 lb	88 mph/ 76 kn	100 mph/ 87 kn	175 mi
6.4 m	5.66 m	2.08 m	6.5 m2	147 kg	240 kg	142 kph	161 kph	282 km

A single-engined two-seat designed and constructed for the 1926 Lympne trials. It was an inverted sesquiplane, the upper wing having a span of 80% of the lower and 83% of its chord.The wings were straight, unswept and of constant chord apart from at the rounded tips, with ailerons on the lower wings only. It featured inward leaning single wide chord interplane struts with wide, faired roots. Two pairs of centre section struts held the upper wing well clear of the fuselage; the absence of stagger made wing-folding easy. Like much of the rest of the aircraft, the wings were of fabric covered wood.
The fuselage was built up on four longerons, spruce at the rear where they were linked into a tapering Warren girder, and ash ahead of the rear cockpit where more traditional wire braced rectangular forms were used.[4] It was topped with a standard rounded decking. The two open cockpits were placed at the leading and trailing upper wing edges and fitted with dual controls. The engine was mounted on a steel plate and smoothly partially cowled to a neatly pointed nose, but with the cylinder heads exposed for cooling. At the rear of the fuselage the fin and tailplane were fabric covered metal structures, though the generous control surfaces were wood framed. Fin and rudder together formed a shape not unlike that of many de Havilland aircraft though more rounded and unbalanced. The main undercarriage was built from a pair of steel V-shaped tubes bearing a single axle and rubber cord shock absorbers. Two aircraft were built for the competition, one to be powered by a 36 h.p. Bristol Cherub III engine and the other by the new 65 h.p. Pobjoy P. Unfortunately, the latter engine failed its own trials not long before the Lympne event and only the Cherub powered aircraft took part. Since the CL.4 had been designed for the 65 hp (48 kW) Pobjoy, the 36 hp (27 kW) Cherub left it seriously underpowered.

Specification
Span	Length	Height	Wing Area	Empty Wt	Max AUW	Cruise Speed	Maximum Speed	Range	Service Ceiling
27 ft 4 in	22 ft 4 in		164 sq ft	480 lb	874 lb		65 mph/ 56 kn
8.33 m	6.81 m		15.24 m2	218 kg	396 kg		105 kph