THE. COMPFR ” SWIFT “
THE Comper Aircraft Co., Ltd., of Hooton Park, Cheshire, is a newcomer to the industry, but to those who remember the early light aeroplane trials at Lympne, the name is not at all unfamiliar because in those days some remarkably good performances were set up by machines designed and flown by Lieut. N. Cowper, who is a principal of the firm now bearing his name.
Lieut. Comper has always been a strong advocate of the really light aeroplane and his Company have produced their little ” Swift ” in the belief that there is a certain potential market for a fast sporting inachine of low initial cost and maintenance. In particular such a machine should be of undoubted value to flying clubs in that it could be used by solo pupils instead of dualcontrol machines which are always very much in demand for instructional purposes. Moreover by using a safe and reliable single-seater machine of 40 h.p. in place of a 90 h.p. or 100 h.p. two-seater the expense entailed during the period of training people to fly could be substantially reduced.
There is a saying in the flying world that if an aeroplane looks right it generally is right, and the truth of this is certainly confirmed by both the appearance and performance of the Comper “Swift.” From whatever position this little machine is viewed one gets the impression of robustness, efficiency and speed and iris difficult to see where the excellent lines of the plane could be improved.
Constructional Features. The structure of this monoplane is unusually interesting, and a detailed inspection of it reveals the fact that all the best features of its predecessor, the C.14.A.3, which put up such a good show at Lympne in 1925 are L” Flight” photo]
incorporated. The fuselage is built in three portions which are bolted together ; this system obviously minimises repairs and replacements and simplifies transport work. UMike the usual fabric covered fuselage there is no ” bag ” (which is somewhat troublesome to remove when an internal inspection is necessary), each portion having its own independent fabric covering. Thus, when any major adjustment or inspection is carried out it is only necessary to strip off a section of the fabric. Provision has also been made for minor inspection by a quickly-detachable panel in the underside of the fuselage. The longerons and intermediate struts are of spindled spruce with plywood gussets, while the top decking is covered with plywood so shaped as to give a pleasing and well stream-lined form.
As the illustrations show, the monoplane wing is without dihedral and is braced by means of V struts which are attached at one end to the wing spars and at the other to the bottom longerons. The wing is built up in three portions the centre section being supported on two fuselage bulkheads situated in front of the cockpit. The front and rear spars of the centre section are attached to extensions of these bulkheads by means of simple steel plates and there is an auxiliary spar which carries part of the aileron control gear. The trailing edge of the centre section is cut away in order to obviate any view-obstruction to the pilot, and the air-speed indicator and altimeter are placed in a convenient position on the rear spar, where they can be read at a. glance. Conforming to usual practice, the wings are of the folding type, and are hinged at the rear spar so that by simply withdrawing locking pins from the front spar they may be folded back close to the fuselage. The spars are made of spruce, spindled and routed for lightness and the form ribs are of built up girder construction
with plywood gussets. The ailerons are hinged to the rear spar and are operated by a combination of cables, cranks and push tubes ; the cables are duplicated. The leading edge of the wing is stiffened with a plywood covering in order to preserve the true wing section profile. The tail unit is of normal monoplane type, and the fin and rudder are built up with steel frames. Both the rudder post and fin post are of high tension steel tube and being cantilever, are devoid of any exterior bracing. Like the main plane, the tail is of fabric
covered wood construction and has no internal or ternal wire bracing. All the controlling surfaces unbalanced.
The undercarriage is of the ” split ” type with shock absorbing units placed within the fuselage. landing shocks are taken by rubber cords in the movement being transmitted from the wheels nearly-vertical tubes to two radius arms which hinged in the centre of the fuselage.
The shock absorbing cord is attached to these two arms. The cockpit is placed immediately behind the wing, and, for so small a machine, is unusually roomy. The seat is so arranged that an equally good view is afforded the pilot both above and below the wing while a simple arrangement permits adjustment to be made in leg room to suit individual cases. The control column is hinged to the end of a longitudinal shaft, which is mounted on two bearings attached to the floor of the cockpit. At the front end of the shaft there is a lever attached to a push-and-pull rod which is linked up to the aileron control gear housed in the centre section, previously mentioned.
The elevator is also worked by a push-and-pull rod which connects the stick to a rocking shaft behind the pilot’s seat and thence by cables to another shaft behind the tailplane. There are no control wires running outside either the fuselage or the wing and this feature is typical of the design as a whole in that there are very few excresences and “bits “to spoil the sleek streamline of the machine. The engine used in the ” Swift ” is the well-known
A.B.C. 40 h.p. ” Scorpion ” and a wooden airscrew is fitted as standard, with a neat spinner which completes the very-fully streamlined forfn of the hose. The power unit is mounted in an ingenious manner so that any vibration is damped out from the machine. The method adopted comprises a patented design of engine bearer in which the 4 engine retaining bolts pass through rand compress rubber blocks in such a manner that there is no metallic contact between the engine and the air frame. The device is the invention of Lieut. Comper and after prolonged tests it has proved extremely effective.
The petrol and oil tanks are mounted in the fuselage in front of the centre section, the feed being by gravity to the engine. The fuel tank has a nine gallon capacity and there is a one-gallon reserve compartment which can be drawn on by means of a simple tap control. The inclusion of detail refinements in the design is a marked feature of the “Swift,” and one which affords a high ,degree of comfort to the owner-pilot who makes a practice of: travelling extensively by air. This is exemplified by the two capacious lockers, situated in the fuselage behind the cockpit. The larger of these contains a strong fibre suitcase measuring 23ins. x 13ins. x Gins. (sufficient for full week-end requirements), and the other provides accommodation for golf clubs, tennis racquets or other light articles. A tray for maps, gloves,
etc., is also fitted under the instrument board across the width of the fuselage.
In regard to the performance, the machine when under test showed itself to be possessed of an unusual range of speed, its maximum being no less than 105 m.p.h. (with a cruising speed of 90 m.p.h.) and a low landing speed of 35 m.p.h. Its initial rate of climb is 700 feet per minute, and its take-off is very good, being 90 yards in 8 seconds. Its normal duration is approximately 350 air miles. The dimensions are as follows :—
Span 24ft,, length 18ft. 4ins., height 5ft. 7ins., wing area 90 sq. ft., dimensions when folded 81 t. Gins., useful load 2751bs., tare weight 4451bs., total weight 7201bs.
The standard model ” Swift ” is marketed, ex-works at £400; a de luxe model is also obtainable at £450. This has extra refinements in the form of a Fairey-Reed propeller, a Rexine-lined cockpit, and a compass, streamlined and mounted in the centre-section. Picketting gear, a waterproof cover for the cockpit and a rear-view mirror is also included in the equipment.
The ” Swift ” is undoubtedly a very attractive little aeroplane and we may expect to hear much more of it in the near future. Other types of aircraft are in the course of preparation by the Cornper concern, and the first addition to their range will be a 2-seater cabin monoplane with side by side seating.