| CLA.2 | |
|---|---|
 | |
| Role | Two-seat light aircraft |
| National origin | United Kingdom |
| Manufacturer | The Cranwell Light Aeroplane Club |
| Designer | Nicholas Comper |
| First flight | 14 September 1924 |
| Number built | 1 |
The Cranwell CLA.2 was a single-engined two-seat biplane built by staff and students of RAF College Cranwell as an entrant to the Lympne Two Seater Light Aeroplane Trials of 1924. It won the reliability prize.
The CLA.2 was the first aircraft completed by the Cranwell Light Aeroplane (CLA) club, formed in 1923 by staff and students at the RAF College Cranwell. The students came from No.4 Apprentices Wing and one of their lecturers, Flt-Lt Nicholas Comper, became chief designer of the three aircraft produced by the club as well as one, the CLA.1, that was not finished. [1] The immediate target was the Lympne Two Seater Light Aeroplane Trials of 1924, but the emphasis was on producing a robust machine that could be simply built and maintained at low cost, suitable for flying schools. [2] It was built from wood and fabric covered throughout. Though it probably had the shortest flying career of any of the CLA's aircraft, it was one of the most profitable.
The Cranwell CLA.2 [1] (or Cranwell II as it sometimes appears) [2] was a largely conventional two-seat single-engined biplane, with some unusual features. It was a single bay sesquiplane the lower wing having an area only 52% of the upper one. [2] 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; [1] these deleterious interplane effects were still not widely appreciated in 1924. [3] The wings lacked stagger and sweep; both had constant chord and ailerons were carried on both wings, with their own internal control runs. [1] The CL.2 was a two-seater (with dual controls as required by the Lympne competition rules [3] ) 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 (3 ft 9 in or 1.14 m), broader than it was deep. [2] 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. [1]
The fuselage was flat-sided, built up around four longerons which were made of spruce at the rear and ash forward of the cockpit. [1] Behind the cockpit, the fuselage narrowed in plan view in a gently curved way to the tail, but less usually Comper made the fuselage reduce in depth also; [1] whilst 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. [2] 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. [2] Forward of the cockpit the lower longerons curved strongly upwards and inwards, meeting the now inward curving upper members at the engine bulkhead, on which was mounted the 32 hp (24 kW) Bristol Cherub I flat-twin driving a two-bladed small diameter propeller. [2] 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, [2] so that the track was about 4 ft (1.22 m). The CLA.2 sat close to the ground, with its wheels only slightly ahead of and below the wing leading edge.
The CLA. 2 first flew, with its designer at the controls, on 14 September 1924. [1] The Lympne competition began two weeks later, with the elimination trials on 27–8 September. [4] Labelled as aircraft No.3 and registered as G-EBKC [5] the CLA.2 completed these successfully, but like several other aircraft failed to complete all the speed and takeoff tests, coming sixth out of seven overall. [6] It did, however fly for nearly 18 hours and covered more than 760 miles (1,250 km), winning the valuable £300 reliability prize. [1] After the light plane trials the CLA.2 went to RAF Martlesham Heath. It was written off by an Air Ministry pilot sometime before 20 May 1925. [5] The Air Ministry compensated the CLA club for this loss. No more CLA.2s were built, but the prize money and the compensation helped to fund the CLA club's next aircraft, the Cranwell CLA.3. [7]
Data from Flight 25 September 1924 [2]
General characteristics
Performance
The Bristol Type 91 Brownie was a light sports aircraft produced in the United Kingdom by the Bristol Aeroplane Company in 1924. It was a low-wing cantilever monoplane aircraft of conventional configuration with fixed tailskid undercarriage. The pilot and passenger sat in tandem open cockpits. It won the £1,000 pound prize for second place at the Lympne light aircraft trials in October 1924.
The Gloster Gannet was a single-seat single-engined light aircraft built by the Gloucestershire Aircraft Company Limited of Cheltenham, United Kingdom, to compete in the 1923 Lympne Trials. Engine development problems prevented it from taking part.
The Vickers Type 253 was a single-engined two-seat biplane general-purpose military machine built to a 1930 government specification. It won a production contract, but this was transferred to the same company's monoplane equivalent, the Wellesley. Only one Type 253 was built.
The Boulton & Paul P.6 was a one-off conventional single-engined biplane built by Boulton & Paul Ltd to test the aerodynamics of different airfoil sections. It was later used as the company sales machine.
The Parnall Pixie was a low powered British single-seat monoplane light aircraft originally designed to compete in the Lympne, UK trials for motor-gliders in 1923, where it was flown successfully by Norman Macmillan. It had two sets of wings, one for cross-country flights and the other for speed; it later appeared as a biplane which could be converted into a monoplane.
The Beardmore Wee Bee was a single-engined monoplane built only once and specifically for the Lympne two-seat light aircraft trials held in the United Kingdom in 1924. This plane won the major prize.
The Cranwell CLA.4 was a single-engined two-seat inverted sesquiplane designed and constructed for the 1926 Lympne trials by an amateur group from RAF College Cranwell. Two were entered, though engine problems prevented one from taking part; the other was eliminated with a broken undercarriage. A third aircraft was amateur-built in Canada and flew until 1934.
The Cranwell CLA.3 was a parasol winged single-engined, single-seat British aircraft built to compete in the Lympne air races of 1925. It was designed and built by an amateur group drawn from staff and pupils at the RAF College Cranwell. Though it won one prize and set a Class record, only one CLA.3 was made.
The RAE Hurricane was a single-seat, single-engined light monoplane designed and built by the Aero Club of the Royal Aircraft Establishment for the 1923 Lympne Motor Glider Competition. It was underpowered with an unreliable engine. Re-engined, it flew in many races, with first place in the 1926 Grosvenor Challenge Cup its greatest success.
The RAE Zephyr was a single-seat, single-engined light pusher configuration biplane designed and built by the Aero Club of the Royal Aircraft Establishment (RAE) for the 1923 Lympne Motor Glider Competition. At a late stage the Aero Club chose to enter the more promising RAE Hurricane instead, using the Zephyr's engine, and the Zephyr itself was abandoned.
The RAE Scarab was a light single-engined single-seat parasol winged modification of the de Havilland Humming Bird, flying in the United Kingdom in 1932. Only one was built.
The Handasyde monoplane was a single-seat light aircraft built for the 1923 Lympne motor glider competition. It competed there but won no prizes.
The Shackleton-Murray SM.1 was a single-engined two-seat light aircraft designed in Britain and flying in 1933. It was a pusher driven parasol winged monoplane. Only one was built.
The Clarke Cheetah was a single-engined amateur built aircraft built in the UK using some parts from a de Havilland Humming Bird to produce a machine that could fly either as a biplane or as a parasol winged monoplane. The single example flew for five years before being converted again in 1936.
The Comper Streak was a single-engined, single-seat racing monoplane built in the UK in the mid-1930s. It was not successful as a racer and only one was produced.
The Surrey Flying Services AL.1 was a single-engined side-by-side two-seat training biplane, built at a UK flying club in 1929. Only one was built, but it was flying until the outbreak of war in 1939 and remains in storage.
The Meyers Midget was a one-off small, low-powered, sporting single-seat sesquiplane, designed and built in the United States in 1926, incorporating several innovative structural features.
The Hanriot H.26 was a French single seat fighter aircraft prototype completed in 1923. Only one was built.
The Caudron C.68 was a two-seat French training and touring aircraft, built in the early 1920s, which attracted interest at the time because of its simple and fast wing folding arrangement. Only a few were produced.
The Cranwell Light Aeroplane Club was formed in 1923 by staff and students of the RAF College Cranwell to design and build light aircraft. One of the members was Flight Lieutenant Nicholas Comper who became the Chief Designer. Comper and the club designed and built four aircraft with the last three types being flown.