The Airdisco Phi-Phi was a single seat

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

glider, designed specifically for the first British gliding competition held at Itford Hill in 1922, an endurance event. It recorded one competitive flight but crashed on a second attempt.

Design

In August 1922 the ''

Daily Mail The ''Daily Mail'' is a British daily Middle-market newspaper, middle-market Tabloid journalism, tabloid conservative newspaper founded in 1896 and published in London. , it has the List of newspapers in the United Kingdom by circulation, h ...

'' newspaper offered a £1,000 prize for the longest duration flight by an unpowered, heavier than air aircraft. The competition was to be organized by the

Royal Aero Club The Royal Aero Club (RAeC) is the national co-ordinating body for air sport in the United Kingdom. It was founded in 1901 as the Aero Club of Great Britain, being granted the title of the "Royal Aero Club" in 1910. History The Aero Club was foun ...

, who chose the site (Itford Hill, on the

Sussex Sussex (Help:IPA/English, /ˈsʌsɪks/; from the Old English ''Sūþseaxe''; lit. 'South Saxons'; 'Sussex') is an area within South East England that was historically a kingdom of Sussex, kingdom and, later, a Historic counties of England, ...

South Downs The South Downs are a range of chalk hills in the south-eastern coastal counties of England that extends for about across the south-eastern coastal counties of England from the Itchen valley of Hampshire in the west to Beachy Head, in the ...

near

Lewes Lewes () is the county town of East Sussex, England. The town is the administrative centre of the wider Lewes (district), district of the same name. It lies on the River Ouse, Sussex, River Ouse at the point where the river cuts through the Sou ...

) and the date (16–21 October). This gave competitors six weeks to design, build and transport their entries. 13 arrived in time and one of these was the

Airdisco The Aircraft Disposal Company (ADC), or Airdisco, was a British firm established in March 1920 to take advantage of the large number of World War I-surplus military aircraft on the market.Gunston 2005, p.7. The company changed name in 1925 to A ...

Phi-Phi, competition number 27. The Phi-Phi was an all wood

parasol An umbrella or parasol is a folding canopy (building), canopy supported by wooden or metal ribs that is mounted on a wooden, metal, or plastic pole. It is usually designed to protect a person against rain. The term ''umbrella'' is traditionall ...

. Its wing section was thick enough to allow for semi-

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

construction, supported centrally by two pairs of

cabane struts 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 struts, which act in ...

and two steeply rising

lift 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 struts, which act in ...

s from the lower

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

longeron In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural fram ...

s, though there were a pair of drag wires from nose to

wing tip A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of sha ...

. The wing plan was unusual compared with the straight edges of most of its competitors, with a gently curving

leading edge The leading edge is the part of the wing that first contacts the air;Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. alternatively it is the foremost edge of an airfoil sectio ...

, elliptical tips and straight

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...

. It had the highest

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

(13.6) of all the Itford gliders. The tip-mounted

ailerons 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 ...

were horn balanced, again unusual. The Phi-Phi had a rectangular cross-section fuselage, with sides that curved in at the nose and, more gently, towards the tail. In plan the sides were straight edged, forming an elongated rhomb. A low aspect ratio, rectangular, all-moving tailplane was hinged on the extreme rear fuselage. The

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...

and

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

formed a tilted, cropped parallelogram with a hinge line above that of the

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

. The cockpit was immediately under the leading edge, well behind the nose. Originally the Phi-Phi had a pair of small main wheels rigidly attached to the lower fuselage directly below the cockpit and aided by a sprung, articulated

tailskid Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

. The wheels were replaced at Itford by a pair of skids and then by skids with small wheels attached to them.

Operational history

The Phi-Phi, flown by Rex Stocken, did not fly until Friday 20 October, the penultimate day of the competition. After a few brief trials and some adjustment to the undercarriage, Stocken made a competition flight that lasted 3 min 18 s. Observers noted that whilst the Phi-Phi lifted off easily enough, like other British gliders present it lacked the rudder authority to hold it into the wind. The following afternoon Stocken attempted another flight but crashed. At the end of the competition he was awarded the Col. Bristow Cup.

Specifications

References

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Flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

, issue=26 October 1922 , pages=626, 629 , url= http://www.flightglobal.com/pdfarchive/view/1922/1922%20-%20062.html 1920s British aircraft Glider aircraft Aircraft first flown in 1922 Parasol-wing aircraft