The Blackburn Triplane was a single-engine pusher single-seater, designed specifically to attack Zeppelins. It flew in 1917, but was not successful.

Development

The

Triplane A triplane is a fixed-wing aircraft equipped with three vertically stacked wing planes. Tailplanes and canard foreplanes are not normally included in this count, although they occasionally are. Design principles The triplane arrangement may ...

was the third unsuccessful attempt at an anti-Zeppelin fighter that involved

Blackburn Blackburn () is an industrial town and the administrative centre of the Blackburn with Darwen borough in Lancashire, England. The town is north of the West Pennine Moors on the southern edge of the Ribble Valley, east of Preston and north-n ...

. The first was Blackburn's own Twin Blackburn and the second the

AD Scout The AD Scout (also known as the Sparrow) was designed by Harris Booth of the British Admiralty's Air Department as a fighter aircraft to defend Britain from Zeppelin bombers during World War I. Design and development The Scout was a very unco ...

, Blackburn building two of the four machines of this type to an Air Department of the Admiralty design. In 1916, the Scout's designer, Harris Booth moved to Blackburn where he created a heavily revised aircraft, the Triplane. The layout of both Scout and Triplane was determined largely by the Admiralty requirement to carry a quick-firing,

recoilless A recoilless rifle, recoilless launcher or recoilless gun, sometimes abbreviated "RR" or "RCL" (for ReCoilLess) is a type of lightweight artillery system or man-portable launcher that is designed to eject some form of countermass such as propel ...

Davis gun that used 2 lb (1 kg) shells. At the time, there was no way of synchronising such a weapon with the propeller, or of mounting it elsewhere than the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

, so a pusher configuration was necessary, the pilot sitting in a nacelle with the gun in its nose. In order to make the aircraft more manoeuvrable and in particular to increase its roll rate, a triplane configuration was chosen. This provided about the same total wing area as that of the biplane Scout with a lower moment of inertia about the roll axis. The Triplane had single-bay wings with heavy stagger, carrying six

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

s. The lower wing was close to the ground so two underwing skids were added below the

interplane strut In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in ...

s. The mid-line of the nacelle, with the engine at its rear, was on the centre plane, giving the pilot a slightly inferior view than from the Scout. Four parallel tail booms ran aft, two from the mid-span of the upper wing and the others from the lower wing. These four members carried the tail. The

tailplane A tailplane, also known as a horizontal stabiliser, is a small lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters and gyroplane ...

, mounted on the upper booms and bearing a full-width

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

, had a span of 18 ft 10 in (5.74 m), no less than 78% of the wingspan. A pair of fin and

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

s joined the upper and lower booms, a height of about 7 ft 6 in (2.3 m). The "reversed"

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

of the Scout was abandoned and the mainwheels were mounted on a single axle supported by two pairs of struts to the nacelle. Though photographs show the gunport, the gun itself was probably never fitted. The Triplane first flew with a 110 hp (80 kW) Clerget rotary engine driving a four-blade, 8 ft (2.46 m) diameter propeller, then later with a 100 hp (75 kW) Gnome with a two-blade propeller.

Operational history

Only one was built. It was accepted by the Admiralty on 20 February 1917, but was rapidly found wanting like the Scout before it. It was struck off charge just a month later, the only Blackburn triplane and the last of their attempts to build an anti-Zeppelin fighter.

Specifications

References

* *

External links

The Triplane Scout
{{Blackburn aircraft

1910s British fighter aircraft Single-engined pusher aircraft Rotary-engined aircraft Triplanes Aircraft first flown in 1917