Bristol Type 148
Encyclopedia

The Bristol Type 148 was a two-seat, single-engine low-wing monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

 built in 1937 to an Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...

 contact for prototype army co-operation
Liaison aircraft
A liaison aircraft is a small, usually unarmed aircraft primarily used by military forces for artillery observation or transporting commanders and messages. The concept developed before World War II and included also battlefield reconnaissance, air ambulance, column control, light cargo delivery...

 aircraft. It lost in the competition to the Westland Lysander
Westland Lysander
The Westland Lysander was a British army co-operation and liaison aircraft produced by Westland Aircraft used immediately before and during the Second World War...

 and only two were built.

Development

The Bristol 148 was built by Bristol
Bristol Aeroplane Company
The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aero engines...

 to an Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...

 order for two prototypes of an army co-operation aircraft meeting Air Ministry specification A.39/34. The successful aircraft was to replace the Hawker Audax and Hector
Hawker Hector
-See also:-Bibliography:* Air Transport Auxiliary Ferry Pilots Notes . Elvington, York, UK: Yorkshire Air Museum, 1996. ISBN 0-9512379-8-5....

 in a wide range of tasks. By 1935 Bristol had gained experience in the design of cantilever low-wing monoplanes powered by radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...

s with the Types 133 and 146
Bristol Type 146
The Bristol Type 146 was a British single-seat, eight-gun fighter monoplane prototype built to a mid-1930s Air Ministry contract. Powered by a radial engine, it was outclassed by Merlin-engined fighters and only one was built.-Design and development:...

, and the Type 148 followed this layout, but had seating for two.

The stressed-skin wings were of constant chord
Chord (aircraft)
In aeronautics, chord refers to the imaginary straight line joining the trailing edge and the center of curvature of the leading edge of the cross-section of an airfoil...

 with rounded tips, and the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

 was entirely of monocoque
Monocoque
Monocoque is a construction technique that supports structural load by using an object's external skin, as opposed to using an internal frame or truss that is then covered with a non-load-bearing skin or coachwork...

 construction. The horizontal tail was set at the top of the fuselage and carried horn-balanced elevator
Elevator (aircraft)
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing. In simplified terms, they make the aircraft nose-up or nose-down...

s; the rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

 was large and pointed. All flying surfaces were fabric-covered. The wing also carried split flaps
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...

 and connected wing-tip slot
Leading edge slot
A leading edge slot is an aerodynamic feature of the wing of some aircraft to reduce the stall speed and promote good low-speed handling qualities. A leading edge slot is a span-wise gap in each wing, allowing air to flow from below the wing to its upper surface...

s to improve the handling at the low speeds required by the specification. The wide-track main undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...

 retracted inwards into the centre-section but the tailwheel was fixed and spatted. Pilot and observer/gunner/bomb aimer sat in tandem cockpits under a continuous canopy, the rear part of which was modified when the .303 in (7.7 mm) Lewis Gun
Lewis Gun
The Lewis Gun is a World War I–era light machine gun of American design that was perfected and widely used by the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces through to the end of the Korean War...

 mounting was changed from Scarff ring
Scarff ring
The Scarff ring was a type of machine gun mounting developed during the First World War by Warrant Officer F. W. Scarff of the Admiralty Air Department for use on two-seater aircraft...

 to a pillar type. The observer could also access a prone aiming position on the floor to drop bombs from the external racks. Two .303 in (7.7 mm) machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....

s were mounted in the port wing.

The intended engine for the Type 148 was the Bristol Perseus
Bristol Perseus
|-See also:-Bibliography:* Bridgman, L, Jane's Fighting Aircraft of World War II. Crescent . ISBN 0-517-67964-7* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...

, but the aircraft made its first flight on 15 October 1937 with a Mercury IX
Bristol Mercury
|-See also:-Bibliography:* Bridgman, L, Jane's fighting aircraft of World War II. Crescent. ISBN 0-517-67964-7* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...

. It was re-engined with a Perseus XII after a landing accident during comparative trials with the Westland Lysander
Westland Lysander
The Westland Lysander was a British army co-operation and liaison aircraft produced by Westland Aircraft used immediately before and during the Second World War...

. Both aircraft met the specification, including the demanding low-speed requirements but the visibility offered by the Lysander's high wing and the security of its fixed undercarriage made it the competition winner. The second prototype, labelled the Type 148B flew in May 1938, powered by a Bristol Taurus
Bristol Taurus
|-See also:-Bibliography:*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...

 II engine and the two machines were used to compare and evaluate the two engine types.

Specifications (Type 148B)

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK