The Slingsby T67 Firefly, originally produced as the Fournier RF-6, is a two-seat aerobatic training aircraft, built by Slingsby Aviation in Kirkbymoorside, Yorkshire, England. It has been successfully used by the UK armed forces and other military training schools around the world for many years as a very competent basic trainer, and is operated safely by many private individuals for standard-level aerobatics. However, it developed a bad reputation in the United States after three fatal crashes during USAF training operations.
The RF-6 was designed by René Fournier and first flew on 12 March 1974. An all-wooden construction, it featured a high aspect-ratio wing echoing his earlier motorglider designs. Fournier set up his own factory at Nitray to manufacture the design, but after only around 40 had been built, the exercise proved financially unviable, and he was forced to close down production. A four-seat version was under development by Sportavia as the RF-6C, but this demonstrated serious stability problems that eventually led to an almost complete redesign as the Sportavia RS-180.
In 1981, Fournier sold the development rights of the RF-6B to Slingsby who renamed it the T67. The earliest examples, the T67A, were virtually identical to the Fournier-built aircraft, but the design was soon revised to replace the wooden structure with one of composite material. Slingsby produced several versions developing the airframe and adding progressively larger engines. The Slingsby T67M, aimed at the military (hence "M") training market, was the first to include a constant speed propellor and inverted fuel and oil systems. Over 250 aircraft have been built, mainly the T67M260 and closely related T3A variants. Although operated successfully in the United Kingdom and Canada, the program would end in disaster in the United States because of fatal crashes following engine failures. The type was meant to not only replace the Cessna T-41 introductory trainer, but meet the Enhanced Flight Screening Program (EFSP) requirements. The US Air Force has no replacement for this type as it no longer provides training to non-fliers. The aircraft were eventually declared in excess of need in the early 2000s.
The largest Firefly operator was the USAF, where it was given the designation T-3A Firefly. The Firefly was selected in 1992 to replace the T-41 aircraft for the command's Enhanced Flight Screening Program, which would include aerobatic maneuvers. From 1993 to 1995, 113 aircraft were purchased and delivered to Hondo, Texas, and the U.S. Air Force Academy, Colorado.
The Air Education and Training Command commander stood down the entire T-3A fleet in July 1997 as a result of uncommanded engine stoppages during flight and ground operations. A major factor driving the decision were the three T-3A Class A mishaps in 1995, 1996 and 1997. Three Air Force Academy cadets and three instructors were killed in T-3A crashes attributed to spin recovery procedures and engine malfunctions. The British-built planes had been purchased for $32 million, and $10 million was spent on fixes to make them airworthy after grounding. "The Air Force found the cost of getting the aircraft or any of the aircraft's components in airworthy condition for resale was prohibitive" and "In September 1999, the chief of staff of the Air Force approved termination of the T-3A EFSP, and AETC declared all T-3A aircraft excess to the command's needs. In 2000, the CSAF requested a new mission be found for the T-3A; however, a study completed in 2002 did not recommend a follow-on mission.""The remaining T-3A aircraft were then stored without maintenance at the Air Force Academy and the Hondo Airport. In the 2002 to 2003 timeframe, the 53 aircraft at the Air Force Academy were disassembled, crated and trucked to Hondo." On September 9, 2006, it was announced the remaining 53 (114 were originally purchased) disassembled T-3 aircraft, which had been declared in excess need for over 6 years, would be scrapped.
RF-6B with Lycoming O-235 120hp engine (1 built)
Slingsby-built RF-6B/120 (9 built)
The T67M was developed from the T67A as a glassfibre reinforced plastic aircraft for a role as a military trainer. The T67M has a 160hp (120kW) fuel-injected Lycoming AEIO320-D1B and a two-blade Hoffman HO-V72L-V/180CB constant-speed propellor. The fuel injected engine with inverted fuel and oil systems allowed the aircraft to perform sustained negative-G (inverted) aerobatics, although inverted spins were never formally approved.
The T67B was effectively the T67A made, like the T67M, in glassfibre reinforced plastic, but without the uprated engine and propellor. A total of 14 T67Bs were produced.
The T67M MkII replaced the single piece canopy of the T67M with a two-piece design, and the single fuselage fuel tank with two, larger tanks in the wings.
A further 40hp was added by replacing the engine in the T67M MkII with the more powerful 200hp (149kW) Lycoming AEIO360-A1E married to a three-bladed Hoffman propellor.
The T67C was the last of the "civilian" variants, based on the T67B with an uprated 160 hp (120 kW) Lycoming engine, but without fuel injection and inverted-flight systems found on the T67M variants. Two further sub-versions of the T67C copied the two piece canopy (T67C-2) and wing tanks (T67C-3) from the T67M MkII. A total of 28 T67Cs were produced across the three versions.
The T67M260 added even more power from the six-cylinder, 260 hp (194 kW) Lycoming AEIO540-D4A5 engine. Unusually for side-by-side light aircraft, most (all?) T67M260s were produced to be flown solo from the right-hand seat to allow student pilots to immediately get used to the left-hand throttle found in most military aircraft - earlier models of the T67M had a second throttle on the left-hand sidewall of the cabin. A total of 115 T67Ms (including the T67M, T67M MkII, T67M200, T67M260) were produced.
The last military version of the T67 family was the T67M260-T3A, of which the entire production run of 114 were purchased by the United States Air Force where it was known as the T-3A. The T-3A was basically the T67M260 with the addition of air conditioning. A few problems were encountered operating the aircraft in the hot-and-high environment of Texas and Colorado, resulting in a number of engine failures thought to be due to vapour-lock problems with the fuel system. Sadly, in three cases, the engine stoppage resulted in fatal stall-spin accidents. Following these accidents, the fleet was grounded and stored without maintenance until being destroyed in 2007.
The Firefly was used as a basic military training aircraft in Canada. The Canadian Fireflies entered service in 1992 replacing the CT 134 Musketeer. They were, in turn, replaced in 2006 by the German-made Grob G-120 when the contract ended. The aircraft were owned and operated by Bombardier Aerospace under contract to the Canadian Forces. Unlike the USAF experience, there were no serious operational or maintenance issues with the Fireflies in Canadian military service.
The Firefly is used by the Dutch air force during pilot selection at Évora Airport, Portugal.
The Firefly is also used as a basic military trainer in the United Kingdom. The aircraft are owned and operated under contract by a civilian company on behalf of the military. In the UK it was under a scheme known as "Contractor Owned Contractor Operated" (CoCo).
Data from Brassey's World Aircraft & Systems Directory
Slingsby Fireflies in popular culture
Published in July 2009.
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