de Havilland Tiger Moth
The de Havilland DH.82 Tiger Moth is a 1930s British biplane designed by Geoffrey de Havilland and built by the de Havilland Aircraft Company. It was operated by the Royal Air Force (RAF) and other operators as a primary trainer aircraft. In addition to the type's principal use for ab initio training, the Second World War had RAF Tiger Moths operating in other capacities, including maritime surveillance and defensive anti-invasion preparations; some aircraft were even outfitted to function as armed light bombers.
For the earlier monoplane also called "Tiger Moth", see de Havilland DH.71 Tiger Moth. For other de Havilland Moth aircraft, see de Havilland Moth.The Tiger Moth remained in service with the RAF until it was replaced by the de Havilland Chipmunk during the early 1950s. Many of the military surplus aircraft subsequently entered into civilian operation. Many nations have used the Tiger Moth in both military and civilian applications, and it remains in widespread use as a recreational aircraft. 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. Many Tiger Moths are now employed by companies offering trial lesson experiences. The de Havilland Moth club, founded in 1975, is now an owners' association offering a mutual club and technical support.
Design and development[edit]
Origins[edit]
Geoffrey de Havilland, the company's owner and founder, had sought to produce a light aircraft superior to two of his previous designs, the de Havilland Humming Bird and de Havilland DH.51.[3] From earlier experience, de Havilland knew the difficulty and importance of correctly sizing such an aircraft to appeal to the civilian market, such as touring, trainer, flying club, and private aviation customers; the firm had great success with a scaled-down version of the DH.51, the de Havilland DH.60 Moth.[3]
The starting point for the DH.82 Tiger Moth was the de Havilland DH.71 Tiger Moth.[4] de Havilland had developed successively more capable Gipsy engines, and the company had produced a new low-winged monoplane aircraft to test them. This aircraft became the first aircraft to be referred to as the Tiger Moth.[5] Improvements made on the Tiger Moth monoplane were incorporated into a military trainer variant of the DH.60 Moth, the DH.60T Moth – the T coming to stand for 'Tiger' in addition to 'Trainer'.[4]
The DH.60T Moth had several shortcomings, thus was subject to several alterations, such as the adoption of shortened interplane struts to raise the wingtips after insufficient ground clearance was discovered while it was undergoing trials at RAF Martlesham Heath.[4] As a result of the Martlesham trials, a favourable report for the type was produced, which in turn led to the type soon being formally adopted as the new basic trainer of the Royal Air Force (RAF). A single prototype, designated the DH.82 Tiger Moth, was ordered by the British Air Ministry under Specification 15/31, which sought a suitable ab initio training aircraft.[4]
One of the main changes from the preceding Moth series was improved 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.[6][4] Access to the front cockpit of the Moth's 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 same centre of lift.[7][4] Other changes included a strengthened structure, fold-down doors on both sides of the cockpit, and a revised exhaust system.[6]
On 26 October 1931 the first 'true' Tiger Moth, the prototype E6, made its maiden flight at Stag Lane Aerodrome, Edgware, London, flown by de Havilland Chief Test Pilot Hubert Broad .[8][4] Shortly thereafter construction of the first 35 production aircraft for the RAF, designated K2567-K2601, began following the issuing of Specification T.23/31; in addition two float-equipped seaplanes, S1675 and S1676, were built according to Specification T.6/33.[4]
Design[edit]
The de Havilland DH.82 Tiger Moth is a single-engined, biplane, taildragger aircraft with two seats in tandem configuration. It was developed principally to be used by private touring customers as well as for pilot instruction for both military and civilian operators. It is typically powered by a de Havilland Gipsy III 120 hp engine; later models are often fitted with more powerful models of this engine, while some have been re-engined by third-party companies.
One 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 bell crank, which lies flush with the lower wing's fabric undersurface covering. This circular bell crank 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 bell crank'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 a slowness to control inputs existed. Some instructors preferred these flight characteristics because of the effect of "weeding out" the inept student pilot.[9]
Numerous examples of the Tiger Moth are still flying today (an estimated 250).[9] The number of airworthy Tiger Moths has increased as previously neglected aircraft (or those previously only used for static display in museums) have been restored.
A number of aircraft have been preserved as museum displays (amongst others) at the:
Privately owned Tiger Moths, type if known, and any history of the airframe:
Aircraft of comparable role, configuration, and era
Related lists