de Havilland Tiger Moth

The de Havilland DH.82 Tiger Moth is a 1930s biplane designed by Geoffrey de Havilland and was operated by the Royal Air Force (RAF) and others as a primary trainer. The Tiger Moth remained in service with the RAF until replaced by the de Havilland Chipmunk in 1952, when many of the surplus aircraft entered civil operation. Many other nations used the Tiger Moth in both military and civil applications, and it remains in widespread use as a recreational aircraft in many countries. It is still occasionally used as a primary training aircraft, particularly for those pilots wanting to gain experience before moving on to other tailwheel aircraft, although most Tiger Moths have a skid. Many are now employed by various companies offering trial lesson experiences. Those in private hands generally fly far fewer hours and tend to be kept in concours condition. The de Havilland Moth club founded 1975 is now a highly organized owners' association offering technical support and focus for Moth enthusiasts.

de Havilland Tiger Moth
Class Aircraft
Type Trainer
Manufacturer De Havilland Aircraft Company Limited
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1931
Country Name Operational Year Retirement Year
Australia View
Belgium View
Brazil View
Burma View
Canada View
Ceylon (Sri Lanka) View
Ceylon (Sri Lanka) View
Czechoslovakia View
Denmark View
Egypt View
Finland View
France View
Germany View
Greece View
India View
Iran (Persia) View
Iraq View
Israel View
Jordan View
Netherlands View
Pakistan View
Poland View
Portugal View
Saudi Arabia View
South Africa View
Spain View
Sweden View
Thailand (Siam) View
United Kingdom - UK (Great Britain) 1932 1959 View
United States of America View
Uruguay View
Yugoslavia (Serbia) View
Zimbabwe (Rhodesia) View
Norway View
Democratic Republic of the Congo View
New Zealand View
ManufacturerName Production From Production To Quantity
De Havilland Aircraft Company Limited 11600 View

The Tiger Moth trainer prototype was derived from the DH 60 de Havilland Gipsy Moth in response to Air Ministry specification 13/31 for an ab-initio training aircraft. The main change to the DH Moth series was necessitated by a desire to improve access to the front cockpit since the training requirement specified that the front seat occupant had to be able to escape easily, especially when wearing a parachute. Access to the front cockpit of the Moth predecessors was restricted by the proximity of the aircraft's fuel tank directly above the front cockpit and the rear cabane struts for the upper wing. The solution adopted was to shift the upper wing forward but sweep the wings back to maintain the centre of lift. Other changes included a strengthened structure, fold-down doors on both sides of the cockpit and a revised exhaust system. It was powered by a de Havilland Gipsy III 120 hp engine and first flew on 26 October 1931 with de Havilland Chief Test Pilot Hubert Broad at the controls.

One distinctive characteristic of the Tiger Moth design is its differential aileron control setup. The ailerons (on the lower wing only) on a Tiger Moth are operated by an externally mounted circular bellcrank, which lies flush with the lower wing's fabric undersurface covering. This circular bellcrank is rotated by metal cables and chains from the cockpit's control columns, and has the externally mounted aileron pushrod attached at a point 45° outboard and forward of the bellcrank's centre, when the ailerons are both at their neutral position. This results in an aileron control system operating, with barely any travel down at all on the wing on the outside of the turn, while the aileron on the inside travels a large amount upwards to counteract adverse yaw.

From the outset, the Tiger Moth proved to be an ideal trainer, simple and cheap to own and maintain, although control movements required a positive and sure hand as there was a slowness to control inputs. Some instructors preferred these flight characteristics because of the effect of "weeding" out the inept student pilot.

Variants

  • DH.60T Moth Trainer/Tiger Moth
  • DH.82 Tiger Moth (Tiger Moth I)
  • DH.82A Tiger Moth (Tiger Moth II)
  • DH.82B Tiger Moth III
  • DH.82C Tiger Moth
  • DH.82C-2 Menasco Moth I
  • DH.82C-4 Menasco Moth II
  • DH.82C-4 Menasco Moth III    
  • DH.82 Queen Bee 
  • PT-24 Moth
  • Thruxton Jackaroo
  • DH.83 Fox Moth


The RAF ordered 35 dual-control Tiger Moth Is which had the company designation DH 82. A subsequent order was placed for 50 aircraft powered by the de Havilland Gipsy Major I engine (130 hp) which was the DH 82A or to the RAF Tiger Moth II. The Tiger Moth entered service at the RAF Central Flying School in February 1932. By the start of the Second World War, the RAF had 500 of the aircraft in service and large numbers of civilian Tiger Moths were impressed to meet the demand for trainers.

During a British production run of over 7,000 Tiger Moths, a total of 4,005 Tiger Moth IIs were built during the war specifically for the RAF, nearly half being built by Morris Motors Limited at Cowley, Oxford.

Training

The Tiger Moth became the foremost primary trainer throughout the Commonwealth and elsewhere. It was the principal type used in the British Commonwealth Air Training Plan where thousands of military pilots got their first taste of flight in this robust little machine. The RAF found the Tiger Moth's handling ideal for training future fighter pilots. Whilst generally docile and forgiving in the normal flight phases encountered during initial training, when used for aerobatic and formation training the Tiger Moth required definite skill and concentration to perform well — a botched manoeuvre could easily cause the aircraft to stall or spin.

A radio-controlled gunnery target version of Tiger Moth appeared in 1935 called the DH.82 Queen Bee; it used a wooden fuselage based on that of the DH.60 Gipsy Moth (with appropriate structural changes related to cabane strut placement) with the wings of the Tiger Moth II. There were nearly 300 in service at the start of the Second World War. It is believed the name "Drone" derived from "Queen Bee". These aircraft retained a normal front cockpit for test-flying or ferry flights, but had a radio-control system in the rear cockpit that operated the controls using pneumatically driven servos. Four-hundred were built by de Havilland at Hatfield, and a further 70 by Scottish Aviation.

De Havilland Canada in Downsview manufactured 1,548 of all versions including the DH.82C and Menasco-engined variants known as the Menasco Moth. The de Havilland Canada operation also built 200 Tiger Moths to USAAF Lend-Lease orders, which were designated for paperwork purposes as the PT-24 before being delivered to the Royal Canadian Air Force. de Havilland Australia assembled 20 aircraft from parts sent from the United Kingdom before embarking on a major production campaign of their own of the DH.82A, which resulted in a further 1,070 being built locally. Additionally, 23 were built in Sweden as the Sk.11 by AB Svenska Järnvägsverkstädernas Aeroplanavdelning, 91 were built in Portugal by OGMA, 38 in Norway by Kjeller Flyfabrikk (some sources say 37 so the first may have been assembled from a kit) and 133 were built in New Zealand by de Havilland Aircraft of New Zealand in addition to a large number of aircraft assembled from kits shipped from the UK.

Coastal patrol

In December 1939, owing to a shortage of maritime patrol aircraft, six flights of Tiger Moths were operated by RAF Coastal Command for surveillance flights over coastal waters, known as "scarecrow patrols". The aircraft operated in pairs and were armed only with a Very pistol. The intention was to force any encroaching U-boat to dive; one aircraft would then remain in the vicinity while the other would search for a naval patrol vessel which could be led back to the spot. Because they were not radio equipped, each aircraft also carried a pair of homing pigeons in a wicker basket to call for help in case of a forced landing at sea. A 25-pound (11.5 kilogram) bomb was sometimes carried, but there is no record of one being dropped in action.

Anti-invasion preparations

In the aftermath of Britain's disastrous campaign in France, in August 1940, three proposals for beach defence systems were put forward. 350 Tiger Moths were fitted with bomb racks to serve as light bombers as a part of Operation Banquet. A more radical conversion involved the "paraslasher," a scythe-like blade fitted to a Tiger Moth and intended to cut parachutists' canopies as they descended to earth. Flight tests proved the idea, but it was not officially adopted. The Tiger Moth was also tested as a dispenser of Paris Green rat poison for use against ground troops, with powder dispensers located under the wings.

Postwar

In postwar use, large numbers of surplus Tiger Moths were made available for sale to flying clubs and individuals. They proved to be inexpensive to operate and found enthusiastic reception in the civil market, taking on new roles including aerial advertising, aerial ambulance, aerobatic performer, crop duster and glider tug.

The Tiger Moth might be confused at first glance with the Belgian-designed Stampe SV.4 aerobatic aircraft which had a very similar design layout, with similar main landing gear, slight wing sweepback for both airframes, and similar engine/cowling design. Several Tiger Moths were converted during the 1950s to Coupe standard with a sliding canopy over both crew positions, not unlike the Canadian-built Fleet Finch biplane trainers which served beside the Tiger Moth in RCAF service as trainers in Canada during the war years. Many ex-RAF examples imported to the Netherlands post war were required by the Dutch civil aviation authorities to be fitted with additional fin area, incorporating an extended forward fillet to the fin.

After the development of aerial topdressing in New Zealand, large numbers of ex-Royal New Zealand Air Force Tiger Moths built in that country and in the United Kingdom were converted into agricultural aircraft. The front seat was replaced with a hopper to hold superphosphate for aerial topdressing. From the mid-1950s, these topdressers were replaced by more modern types such as the PAC Fletcher, and a large number of New Zealand Tiger Moths in good flying condition were then passed to pilot owner enthusiasts. It has been claimed that more people have flown themselves in Tiger Moths than in any other plane.

Royal Navy Tiger Moths utilised as target tugs and "air experience" machines became the last military examples when that service purchased a batch of refurbished ex civil examples in 1956. One became the last biplane to land on an aircraft carrier (HMS Eagle) in the English Channel during the Summer of 1967. On takeoff, the wind over the deck allowed the aircraft to fly but it was slower than the carrier, which turned hard to starboard to avoid a possible collision. These planes remained in service until the early 1970s.

Tiger Moths were often modified to stand in for rarer aircraft in films. Notably, Tiger Moth biplanes were used in the crash scenes in The Great Waldo Pepper, standing in for the Curtiss JN-1. Due to the popularity of the design and the rising cost of flyable examples, a number of replicas (scale and full-size) have been designed for the homebuilder, including the Fisher R-80 Tiger Moth and the RagWing RW22 Tiger Moth.

Flying the Tiger Moth

The Tiger Moth responds well to control inputs, and is fairly easy to fly for a tail-dragger. Its big "parachute" wings are very forgiving, and it stalls at a speed as slow as 25 knots with power. Its stall and spin characteristics are benign. It has some adverse yaw, and therefore requires rudder input during turns. The Tiger Moth exhibits the fundamental requirements of a training aircraft, in being 'easy to fly, but difficult to fly well' ; the aircraft's benign handling when within its limits make it easy for the novice to learn the basic skills of flight. At the same time techniques such as coordinated flight must be learnt and used effectively, and the aircraft will show up mishandling to an observant instructor or attentive pupil. As training progresses towards more advanced areas, especially aerobatics, the skill required on the part of a Tiger Moth pilot increases. The aircraft will not, like some training aircraft, 'fly its way out of trouble' but will instead stall or spin if mishandled. However the stall and spin remain benign, again showing up deficient piloting without endangering the aircraft or the crew. These characteristics were invaluable to military operators, who must identify between pilots with the potential to go on to fly fighter aircraft, those more suited to lower-performance machines and those who must be relegated to non-pilot aircrew positions.

Because the Tiger Moth has no electrical system, it must be started by hand. This needs to be done with care to prevent being struck by the propeller, which would result in serious injury. Being a tail-dragging biplane, taxiing also requires care. The pilot cannot see directly ahead, so the lower wing can hit obstructions, and it is susceptible to gusts of wind on its inclined, large, upper wing.

The takeoff is uneventful, and it has a reasonable rate of climb. However, full power should not be maintained for more than a minute to avoid damaging the engine.

The Tiger Moth's biplane design makes it strong, and it is fully aerobatic. However, it has ailerons only on its bottom wing, which makes its rate of roll relatively slow for a biplane, and the ailerons on a Tiger Moth normally operate with a heavy degree of designed-in differential operation (mostly deflecting up, hardly at all downwards) to avoid adverse yaw problems in normal flight. Most manoeuvres are started at about 90 to 110 knots, and it has a Velocity Never Exceeded (VNE) of 140 knots. It is important to lock the automatic slats (leading edge flaps) during aerobatic manoeuvres.

There are two methods of landing. "Wheeler" landing involves pushing the plane on to the runway at a moderate speed with just the main wheels on the ground, with the tail held up until speed reduces. It does not tend to bounce. Unlike most tail draggers, slow speed Three point landings are quite difficult because there is not enough elevator authority to bring the tail down to the correct three point attitude. This means that the tail needs to be brought down sharply at just the right speed in order for the angular momentum to carry it down sufficiently.

The open cockpit allows pilots to move their heads over the side to see the runway during approach and landing. As the aircraft is a tail dragger, it is essential to land it straight with no sideways movement, to avoid ground loops.

One often undocumented feature is that the carburetor de-icing mechanism is activated automatically when the throttle is reduced. This means that when an engine is running poorly due to ice the pilot must reduce power even further and then wait for the ice to melt.

Role Trainer
Manufacturer de Havilland Aircraft Company
de Havilland Canada
Designer Geoffrey de Havilland
First flight 26 October 1931
Introduction February 1932 [1]
Retired 1959
Status Retired from military service, still in civil use
Primary users Royal Air Force
Royal Canadian Air Force
Royal Australian Air Force
Royal New Zealand Air Force
Produced 1931–1944
Number built 8,868[2]
Developed from de Havilland DH.60 Moth
Variants Thruxton Jackaroo


General characteristics

  • Crew: 2, student & instructor
  • Length: 23 ft 11 in (7.34 m)
  • Wingspan: 29 ft 4 in (8.94 m)
  • Height: 8 ft 9 in (2.68 m)
  • Wing area: 239 ft (22.2 m)
  • Empty weight: 1,115 lb (506 kg)
  • Loaded weight: 1,825 lb (828 kg)
  • Powerplant: 1 x de Havilland Gipsy Major I inverted 4-cylinder inline, 130 hp (100 kW)

Performance

  • Maximum speed: 109 mph at 1,000 ft (175 km/h at 300 m)
  • Range: 302 miles (486 km)
  • Service ceiling 13,600 ft (4,145 m)
  • Rate of climb: 673 ft/min (205 m/min)

End notes