Type: all-composite business jet prototype
Powerplant: 2 x Williams FJ-44 turbofan engine
First flight: 12 July 1988 (pilot: Fitz Fulton)
The Model 143 Triumph was an all-composite, eight-seat pressurized business jet prototype, initially developed by Scaled Composites under the auspices of Beech Aircraft and designed around the then-unflown Williams/Rolls-Royce FJ44 turbofan engine. Tuna was originally supposed to be three airplanes: piston, turboprop and jet powered. The piston powered one was the first to be built and the jet was going to be second.
In the middle of the eighties, second-hand aircraft were viewed as "formidable" competition by general aviation companies. The problem was the large number of cheap, second-hand types around. In a five-year period from 1977, the US general-aviation industry had built 3,300 turboprop aircraft and 1,450 jets. Technology in general aviation had been slowing down. The "visual punch" of Burt Rutan's radical designs were just what Beechcraft needed to tempt buyers away from used aircraft. SCI was acquired by Beech in 1985 after Rutan built the 85 per cent scale prototype of the company's Starship 1 canard business turboprop. "We must stimulate the market by offering products that have no competition in the second-hand market," said Beech president James Walsh in October 1986.
Along with the Starship project, Scaled Composites (Beech's advanced development arm at the time) developed several other types, including the Next Generation Cabin Twin (NGCT), a new high-technology twin-engined business aircraft. The new type would be offered with jets, but also with piston engines and turbofans, "in a bid to stimulate purchases by US customers now more likely to buy a good used aircraft". Six to eight people could be accommodated in the new aircraft. Burt Rutan's foreplane trademark was complemented by a forward swept plane atop the fin, featuring area-ruling to give good pressure recovery and low drag. A ventral extension of the tailfin ensured that directional control was maintained at high angles of attack. The foreplane included pitch-control surfaces, while elevators may be incorporated in the tailplane.
The top-of-the-line version, powered by the brand-new (and as yet untested) Williams FJ44 turbofans, would cruise at Mach 0.7 at 35,000 ft and fly 0.8 n.m. on just one pound of fuel, according to Burt Rutan. The piston version would cruise at 260 kt at 25,000 ft and go 1.5 n.m. on one pound of fuel. Rutan aimed to sell the twin for less than half the price of existing light jets. "This new class of light, light jet will use [expensive] carbon fibre only where needed," said Rutan. The jet variant would sell for $1.2 million while the purchase price of the piston version was likely to be around $750,000. Rutan started work on both versions, but development of the turboprop version (the cost of which was estimated at $1 million) was delayed as no engine had yet been selected. Full-scale versions of the aircraft were to be built to prove the concept, along with a static-test article and a cabin mockup.
Initially, the NGCT was pretty "hush-hush". When the program was revealed in the fall of 1986, Burt Rutan refused to reveal photographs of the prototype that was almost complete, but displayed a model at Anaheim which showed how highly unconventional the new design was. "Now the tail [of this aircraft] is the last thing to shock up, not the first," said Rutan. The drag-rise Mach number would be 0.75, allowing for "future performance enhancement", if higher thrust versions of the small Williams engine were to become available. The T-tail was also claimed to reduce fuselage-bending stress. The wing would be wet but, unlike in some then-recent designs, did not feature tip sails. According to Rutan, the use of composites enabled the fuselage to be wider than that of the King Air, but narrower than that of the competition, because of the simplified structure and thinner skin, and parts would be 95 per cent fewer than those of a conventional business aircraft. The fuselage was to have a large cargo loading door.
On the jet-powered variant, the engines were mounted fairly close to the fuselage on the upper surface of the main wing with the inlets at approximately midchord. The Beech cabin-class twin was in effect the first civil application of the Williams FJ44 turbofan. Back in 1986, Beech was the only company to say that it intended to adopt the FJ44 turbofan, though engine-maker Sam Williams maintained that others were interested. Engine certification would be geared to Rutan's project requirements.
Design and construction of the cabin-class twin was undertaken by Scaled Composites on behalf of new owner Beech, a proof-of-concept demonstrator powered by two 1,800 lb-thrust Williams FJ44 turbofans and called the Tuna at Scaled Composites, the aircraft started life as the Cabin Twin, but the story goes that someone figured CT also stood for "Charlie Tuna", hence the program's humorous inhouse monicker. The prototype aircraft sported considerably thicker windscreen pillars than was suggested in Beech publicity material. This may have resulted from manufacturing the cabin as a filament-wound shell, without the use of local built-in reinforcements around each aperture, which may have been cut out subsequently.
When Bleck took over from Walsh as President of Beech, he tried to kill the program, but Burt Rutan convinced him to fly the jet, so the piston-engined aircraft was finished as the jet. The aircraft made its first flight on July 12, 1988 in the hands of Scaled Composites test pilot, Fitz Fulton. This also marked the first flight tests of the FJ44. The subsequent test program, which consisted of over 100 hours of flight tests, confirmed the performance and operating characteristics of both the engines and the airplane. The Triumph was tested to over 41,000 ft., at speeds up to .69 Mach. Pressurization systems were developed, installed, and tested, basic handling qualities and performance tests were conducted, and a significant body of engine tests were performed. One prominent issue was to prevent wing root from cracking, a result from Beech's insistence to combine aluminum and composite materials, which was solved at the time by engineer Rob Dawg.
Scaled Composites eventually parted with Raytheon's Beechcraft, and a dispute ensued over ownership of designs. This resulted in Rutan getting back several of the aircraft designs he had developed for the company, including the Model 143, now called the Triumph. SCI was acquired by by Wyman-Gordon, and Rutan continued to fly the Triumph, logging some 27h in 65 flights, reaching Mach 0-69 at 30,000ft, and achieving a better than 0-6 n.m./lb fuel flow. The next step was to install pressurisation, for which the all-composite fuselage had already been proved, to demonstrate a 41,000 ft ceiling as well as igh-altitude performance, handling, stability, and control.
In October 1989 Rutan announced that to manufacture the Triumph cabin class twin he was seeking an industry partner with experience in certificating aircraft to US Federal Aviation Administration regulation. The company believed the all-composite Triumph could be certificated, but needed a partner experienced in avionics integration, airframe assembly, and marketing. Talks took place with established aircraft manufacturers in the United States and elsewhere. In 1991, Williams was approached by Scaled Composites to furnish engines to get the dormant Triumph project back off the ground, but nothing came of these plans and the Triumph never flew again.
Always one of Rutan's own favorites, the Triumph stood proudly at the entrance of the company's main hangar in Mojave for several years. Though it never entered production and is always overlooked by most Beechcraft historians, despite its development under the company's auspices, the Triumph demonstrated the performance and economy promised by the FJ44 engine.
Population: 1 [N143SC]
Crew/passengers: 10 (including two crew)