Folland Gnat Prototype G-39-2 on take off run in 1955
Folland Gnat Prototype (G-39-2) on take off run in 1955
The Folland Aircraft Company Gnat fighter, designed by W.E.W. (Teddy) Petter, was the result of a private venture development of the Folland Midge and the prototype (G-39-2) first flew on 18th July 1955.
Petter's concept was for a light-weight fighter to capitalise on the range of new, modern jet engines combined with a simply engineered fuselage and wing, making it affordable and easy to manufacture with a minimum of engineering resources.
Folland Aircraft Company promptly commenced work, privately financing the project which received the designation Fo-141, along with the name Folland Gnat. The design was strongly influenced by Operational Requirement OR.303, which sought a capable lightweight fighter aircraft. Development went ahead, irrespective of any external orders or financing from any British government department, such as the Ministry of Supply.
The new lightweight turbojet engines, enabled the concept to be realised. Initially, the Folland Gnat was intended to be powered by a Bristol BE-22 Saturn turbojet engine. Unfortunately, further development of the Bristol Saturn was cancelled and so the more capable Bristol Orpheus turbojet engine was adopted in its place. Unfortunately, that was a problem as well, as the Bristol Orpheus was not fully available at the time. So, and in order to avoid further delay, it would be fitted with the less powerful Armstrong Siddeley Viper 101 turbojet engine.
Using a different power plant between prototypes and production aircraft is not ideal, so Folland created a 'proof-of-concept' demonstrator, designated Fo-139 Midge. It utilised a nearly-identical airframe, along with very similar avionics, in order to test and verify the design in advance of full prototype being built.
The Fo-139 Midge took to the air on 11th August 1954, piloted by Folland's chief test pilot Edward Tennant.
Despite the low-powered engine, the Folland Midge was able to break Mach 1 whilst in a dive and it proved to be very agile during its test programme. Sadly on 20th September 1955, the Midge was destroyed in a crash at Chilbolton, which claimed the life of Swedish test pilot Max Mathez, who clipped the trees during take-off. The coroner recorded a verdict of ‘misadventure’ possibly due to human error and the selection of the wrong control switches during the departure.
The nature of its development as a private venture, coupled with its short lifespan, resulted in a disappointing lack of interest from the RAF. However, Senior Officers did encourage the design of a similar aircraft, specifically for fast jet training purposes.
As it happened, Folland Aircraft had an enlarged version of the original light-fighter concept, the Folland Gnat. It differed from the Folland Midge with larger air intakes suitable for the proposed Bristol Orpheus engine and boasted a slightly larger wing. It also had provision for the for a 30 mm ADEN cannon in each intake lip.
Engine testing
Engine testing with Mr Petter looking on - June 1955
The first prototype Fo.140 Folland Gnat (G-39-2) flew at RAF Boscombe Down on 18th July 1955 and following favourable reports, six aircraft were ordered by the British Ministry of Supply for evaluation purposes.
Although the British evaluation brought no orders (The Hawker Hunter was selected as the eventual winner of the fly-off competition). It was also evaluated in 1958 as a replacement for the De Havilland DH112 Venom. In the same year, orders for Folland Gnat F1 and FR1 variants were placed by Finland (13 aircraft) and Yugoslavia (2 aircraft) and although there were plans for F3 and F4 variants, these were never built.
India placed a large order for the type and initial aircraft were produced and first flown in the UK during 1958. The aircraft was so successful with the Indian Air Force that within 2 years, a licencing agreement was in place for production by Hindustan Aeronautics Limited, who built 175 aircraft.
The Folland Gnat concept was said to be a factor in issue the NATO NBMR-1 (NATO Basic Military Requirement) for a low level strike/attack light fighter, issued by the Mutual Weapons Development Team. Unfortunately, the Folland Gnat itself was never evaluated for the requirement, which was eventually won by the Fiat G.91. The requirement itself was later shrouded in international controversy and eventually abandoned after the loss of the Fiat prototype.
Greater success was seen with the 2-seat Folland Fo.142 Gnat trainer, especially after the take-over of the company by Hawker Siddeley. At last, production turned towards reasonable numbers with orders coming from the Ministry of Aviation, between 1960 and 1962.
In all, 449 airframes bearing the Gnat designation were built in 6 main variants, plus the HAL Ajeet fighter and trainer, built under licence in India.
The Folland Fo.144 Gnat T.1 is probably most famous however, as being the aircraft of choice for the world-famous RAF Display Team, The Red Arrows.
Folland Gnat in service with the RAF Red Arrows.jpg
Folland Gnat in service with the RAF Red Arrows
RAF pilots graduated from basic training on the Hunting Percival - BAC Jet Provost and once they had gained their wings they were selected for one of three streams: fast jet, multi-engine aircraft or rotary (helicopters). Those selected for fast jets were posted to RAF Valley on Anglesey where they experienced advanced training on the Folland Gnat T.1. After gaining sufficient success (normally around 70 hours) they would then move on to Hawker Hunter.
Following the introduction of the Hawker Siddeley Hawk into the training role in April 1976, the Folland Gnats were withdrawn from service. The largest operator, 4 FTS at RAF Valley, retired its last Gnat in November 1978.
All serviceable aircraft were then sent to No. 1 School of Technical Training, at RAF Halton, as well as other surplus Folland Gnats becoming ground training airframes at other smaller training establishments.
The RAF eventually retired the training airframes, with many being sold to private operators. A large number are still flying today (see list below).


Specification (F.1)

Powerplant            1 x Bristol Siddeley Orpheus 701-01 turbo jet – 4,705lbf (20.9kN)
Span 28 ft 8 in (6.73 m)
Maximum Weight 9,040 lbs (2,175 kg)
Capacity 1 Pilot
Armament 2 x 30mm Aden / 2 x 500 lb bombs (227 kg) or 18 x 3” Rockets (76mm)
Maximum Speed 695 mph (1,120 kph) at 20,000 ft
Maximum Range 500 miles (800 km)


Number built

Folland Fo.140  1 Private Venture                                                                    
Folland Gnat F.1  235
Folland Gnat FR.1  1
Folland Gnat F.2  1 Prototype
Folland Gnat T.1  105
HAL Ajeet  89



Folland Gnat T.1    
Essendon Aviation Museum, Essendon Airport, Melbourne, Victoria, Australia           
Folland Gnat F.1 
Central Finland Aviation Museum, Tikkakoski, Finland.
Folland Gnat F.1 
Central Finland Aviation Museum, Tikkakoski, Finland.
Folland Gnat F.1
Finnish Aviation Museum in Vantaa, Finland.
Folland Gnat F.1 
Karhula Aviation Museum, Lentokentäntie 234, 48720 Kotka, Finland       
Folland Gnat F.1
Gate Guardian at Rovaniemi Airport, Finland
Folland Gnat F.1 
Aviation Guild of Lahti, Vesivehmaa Museum, Lentotie 89, FI-17130 Finland
Folland Gnat F.1
Karelia Aviation Museum, Lentokentäntie 37, 53600 Lappeenranta, Finland
Folland Gnat F.1 
Karelia Aviation Museum, Lentokentäntie 37, 53600 Lappeenranta, Finland
Folland Gnat F.1 Diamond Garden area, Chembur, Mumbai, India.
Folland Gnat F.1 District Court, Feroz Gandhi Market, Ludhiana, India
Folland Gnat F.1 
PAF Museum Karachi, PAF Faisal Air Base Shahrah-e-Faisal, Pakistan
Folland Gnat F.1
RAF Museum Cosford, Shropshire, UK
Folland Gnat F.1
Midland Air Museum, Coventry, UK
Folland Gnat F.1
Solent Sky, Southampton, Hampshire, UK
Folland Gnat T.1
(XM697 / XM693)
Outside GE Aviation factory at Hamble, Hampshire.
Folland Gnat T.1 
Science Museum, London, UK
Folland Gnat T.1
Farnborough Air Sciences Trust, Farnborough, Hampshire.
Folland Gnat T.1 
Solent Sky, Southampton, Hampshire, UK
Folland Gnat T.1
Newark Air Museum, Winthorpe, Newark, Nottinghamshire, UK.
Folland Gnat T.1 
(G-NATY (XR537)
De Havilland Aviation, Bournemouth Airport, UK.
Folland Gnat T.1 
Heritage Aircraft Trust, North Weald Airfield, UK
Folland Gnat T.1
Red Arrows, RAF Scampton, Lincolnshire.
Folland Gnat T.1 
RAF Museum Cosford, Shropshire, UK
Folland Gnat T.1 
Heritage Aircraft Trust, North Weald Airfield, UK
Folland Gnat T.1
(XS111 / XP504)
Heritage Aircraft Trust, North Weald Airfield, UK
Folland Gnat F.1 
(G-FRCE / XS-104)
North Weald Airfield, UK
Folland Gnat T.1 
(XM694 / N694XM)
Pima Air and Space Museum, Arizona, USA
Folland Gnat F.1 
March Field Air Museum, Riverside, California, USA.
Folland Gnat T.1 
(XP538 / N19GT)
Planes of Fame Air Museum in Chino, California, USA.
Folland Gnat T.1 
(XR572 / N572XR)
Rocky Mountain Metropolitan Airport, Colorado, USA.
Folland Gnat F.1 
Museum of Aviation, Belgrade, Serbia
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