Fournier RF-6

Slingsby T67 Firefly

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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, where the Royal Air Force used 22 Slingsby T67M260's as their basic trainer between 1995 and 2010, with over 100,000 flight hours flown out of RAF Barkston Heath.

The Slingsby has also been used by the Royal Hong Kong Auxiliary Air Force, the Royal Jordanian Air Force (still currently used) and other military training schools around the world for many years.

It is a very competent basic trainer and is still operated by many private individuals for standard-level aerobatics training.

It was the HRH Prince William, Duke of Cambridge's basic trainer during his RAF flying officers course based at RAF Cranwell.

He completed his initial elementary test in a Slingsby T67M260, registration G-BWXJ in 2009. It is also used by Tom Cassell's, a British Aerobatic Champion.

However, in the mid-1990s, the aircraft became controversial in the United States after three fatal accidents during USAF training operations, although a USAF investigation eventually attributed the accidents primarily to pilot error.

Development

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 the United States because of a fatal crash following an engine failure.

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.

Operational history

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 Municipal Airport, Texas, and the U.S. Air Force Academy in Colorado.

The Commander of the Air Education and Training Command (AETC) 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: i.Spin (flight), 1996: ii.Practice forced landing and 1997: iii.Stall (flight) during low level circuit.

Three Air Force Academy cadets and three instructors were killed in these T-3A mishaps/accidents.

The USAF Accident Investigation Board report summary attributed the three fatal accidents to the following:

i. 22 February 1995: The instructor pilot (IP) failed to apply anti-spin rudder as directed in flight manual.

The IP’s spin academic instruction, flying training, and error analysis experience did not adequately prepare him to recognize his improper rudder application.

ii. 30 September 1996: During a simulated forced landing, the engine quit for some unknown reason.

After the engine quit, the aircraft entered a stall from which the IP was unable to recover prior to ground impact.

iii. 25 June 1997:

The aircraft departed controlled flight for an unknown reason during the turn to downwind. The IP’s failure to recognize this departure and take immediate positive corrective action was the primary cause of the accident. (The AIB President found no clear and convincing evidence of mechanical failure.)

The British-built planes had been purchased for $32 million, and following the third accident, $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 Chief of Staff of the Air Force 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.

Edwards Air Force Base still operates a single T67M Slingsby for test pilot training which originates from the fuel system flight tests in 1998.

Although the United States Air Force terminated the EFSP, it now uses the less capable Diamond DA20 for Initial Flight Screening (IFP) through the 3rd party Doss Aviation.

Variants

T67A

Slingsby-built RF-6B/120 certified on 1 October 1981, nine built.

T67M Firefly

First flown on 5 December 1982 and certified on 2 August 1983 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.

A total of 32 T67Ms (including the later T67M MkII) were produced.

T67B


First flown on 16 April 1981 and certified on 18 September 1984 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.

T67M MkII Firefly


Certified on 20 December 1985 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.