The Civilian Coupé is a British, single-engined two-seat private monoplane built starting in 1929. Only five were made and it was the Civilian Aircraft Company's only product, but one still flies in the UK.
In 1928 Harold Boultbee left Handley Page to form the Civilian Aircraft Company. The Coupé was its only product, an aircraft of mixed metal and wood construction  It was aimed at the private market and was quite advanced for its day. The Coupé is a high-winged monoplane, the wing vee-strut braced to the lower fuselage longerons. The wings fold for transport and storage. They have almost constant chord, with slight taper outboard and a gentle reduction in chord at the trailing edge to help rearward visibility. There is glazing at the centre section for an upward view from the enclosed cabin where pilot and passenger sit in seats not quite side by side.
The fuselage has a square cross-section, decreasing in depth towards the tail and is plywood covered. Tail surfaces are nearly rectangular, though the rudder extends below the tailplane and elevators to the bottom of the fuselage, where it curves in smoothly. A split axle undercarriage is mounted from the lower fuselage with the main legs fixed to the upper longerons; there is a tailskid. Unusually for its time, the wheels have brakes and the flying controls are pushrod operated.
The Coupé first flew in July 1929, powered by a 75 hp (56 kW) A.B.C. Hornet air-cooled flat four engine driving a two-bladed propeller. The sole aircraft with this engine became known as the Mk.I and all later Coupés, which used the 100 hp (75 kW) Armstrong Siddeley Genet Major I five-cylinder radial, as Mk.IIs.In both engine installations, cylinder heads are exposed for cooling. It took about 18 months before teething problems, chiefly vibration transmitted by the engine mounting was cured.
In all, five Coupés were probably built and certainly five are recorded by UK Civil Aviation Authority, one of which, G-ABNT, still flies in 2010 though no others survive. The last Mk.II built went immediately to a German owner and crashed during the war but the other three Coupés were raced in the UK between 1931-3, though without great success. Later one of them was sold to a Dutch owner and the prototype also went abroad. By 1934 the Civilian Aircraft Company had closed down and only two Coupés were active.
Coupé Mk.I - A.B.C Hornet engine
Coupé Mk.II - Armstrong Siddeley Genet Major I engine
Two seat (side by side)  sportplane  (Mark II)
1  Armstrong Siddeley Genet Major I
Length 5,59 m, height 1,91 m, span 10,82 m, wing area 15,59 m2
Empty weight 447 kg, flying weight 680 kg
Maximum speed 177 km/h, cruising speed 154 km/h, range 480 km, climb 4,1 m/sec
Mark II
Civilian Aircraft Co Ltd/Hedon 16.09.31 Sold Germany 10.32 to E.Panzer, crashed during the war ?
Civilian Coupé
Mr. Cliff's trip to Diisseldorf, which
was reported in FLIGHT last week, has borne good fruit,
as the " Civilian Coupe " which he tcok out, has now been
sold in that country.
T H E Civilian Coupe is one of the latest light aeroplanes to be put on the
1 market. Mr. H. D. Boultbee, the designer of the machine, and a Director
of the Company, has been connected with the practical side of the aircraft
industry for more than twenty years. An experimental machine has
been flying for eighteen months, and from the experience gained with this
all the " teething troubles " have been eliminated in the production type,
which will be ready for delivery early in the spring of 1931.
The Civilian Coupe Mark II is a high wing cabin monoplane with folding
wings. It is a two-seater light aeroplane and the pilot's and passenger's seats
are slightly staggered in relation to each other in order to give sociable seating
without excessive width.
A remarkable feature of the machine is the view obtained from the pilot's
seat. Tapered wing roots and a large window in the centre section allow the
pilot to see clearly while doing a turn, and there is a complete circle of vision
on eye-level and below. Owing to the narrow engine cowling the forward
and downward view on each side of the engine is excellent. The horizontal
arrangement of the cylinders in the " Hornet " enables the cowling to be
dropped towards the front, and so provides an excellent view straight ahead,
where in most machines the view is likely to be somewhat obscured.
The fuselage is of mixed construction, in that the rear portion is constructed
of 3-ply planking on spruce members, while the forward part, where
the greater loads are concentrated, is built up of steel tubes bolted together
The whole of the rear fairing on top of the fuselage is easily detachable for
inspection. The wings, tail plane, elevators, fin and rudder are all covered
with plywood.
The undercarriage is of the divided type, fitted with Dunlop wheels and
Bendix brakes, the brakes being capable of being operated either together or
independently. A tail wheel with castor action is fitted.
The power plant, which has been standardised for the Civilian Coupe
Mark II, is the 85 h.p. A.B.C. " Hornet." Originally some difficulty was
experienced in designing a suitable engine mounting, and considerable
vibration was experienced. This trouble has now been entirely overcome,
and in the production type of machine the engine is said to run very smoothly.
Purchasers desiring higher performance can obtain the machine fitted with
the Armstrong Siddeley " Genet Major," of 105 h.p. With that engine,
however, the price is slightly higher, i.e., £780 as against ^650 for the Hornet
engined machine.