It may have been long in the making, but the high-flying, spacious HondaJet is winning global admiration ahead of its debut next year
Even in an era of instant communication, it is possible to develop an aircraft in total secrecy and announce it with a flourish just two or three years before entry into service. The most prominent example at EBACE last May was admittedly a remodelling of an existing design, but showed how far down the track you can go before pulling back the curtain for the waiting media.
Honda has taken the very opposite approach with its debut aircraft, whose gestation period has already been more than 25 years. The company’s entry-level business jet is not expected to receive FAA certification (followed by EASA) before the second half of 2013, with deliveries beginning shortly afterwards.
Seasoned observers have commented that such a slow path to commercial operation is possible only because the project has had the financial backing of one of the world’s leading carmakers. The HondaJet represents such a radical departure from conventional aeronautical design thinking, however, that most believe it will have been worth the long wait.
Honda began research into bizjets in 1986 as a sideline to its automotive business and built an all-composite aircraft, the MH02, to test out its ideas. Michimasa Fujino, who had joined Honda in 1984 with a degree in aeronautical engineering, spent several years with the group’s R&D team in the Americas and in 1997 became large-project leader for the HondaJet programme.
It was Fujino who was responsible for the aircraft’s revolutionary over-wing engine mounting. He led the research into composite construction and also helped design an airfoil and nose using natural laminar flow techniques to increase speed without creating turbulence.
An engine, the then HF118, was developed in collaboration with GE in 1999. It was test-flown on a Cessna Citation and the HF120 that will be fitted to production aircraft evolved from it. The HondaJet itself made a proof-of-concept flight in 2003. Yet even at this stage, Honda was not ready to commit to commercialisation, Fujino told EVA in an exclusive interview.
Honda Aircraft Co was founded only in 2006, with Fujino as its founding president and CEO. Explaining the long timeline, he said: “It was the end of that year, almost into 2007, before the project went commercial, so five years since then is not untypical.”
Engineering challenge
The HondaJet will typically accommodate five passengers, with a club four plus an optional side-facing fifth seat. Mounting the engines on pylons over the wing, a feature Honda patented in 2000, maximises space inside the cabin as well as providing more externally accessible cargo space — a total of almost 1.87cu metres (66 cu ft) in the nose and aft.
Aircraft engines in their normal position require structures that “eat up” space within the fuselage, Fujino says. Relocating them over the wing was a difficult engineering challenge that initially looked likely to increase the weight and create problems with vibration and flutter – until Honda found what he describes as the “sweet spot”.
The design that has emerged is claimed to be the fastest, highest-flying, most fuel-efficient and most spacious jet in its class, with the bonus of offering a quiet ride. And the engine placement not only displaces noise away from the cabin, but also reduces ground-detected noise when the aircraft flies overhead.
Although Honda has never openly discussed the matter, the current spec sheet suggests some subtle dimensional changes over the last five years. The HondaJet in its final form is longer than before at 12.99 metres, almost identical to the Citation CJ1, but has a slightly reduced wingspan than in the original specification, 12.12 metres. The cabin interior is 1.46 metres high and 1.52 metres wide, giving 30% more internal space than Cessna’s soon-to-be-replaced CJ1.
The carbon fibre fuselage is around 10% lighter than the usual aluminium, though Honda changed its mind and opted for strengthened aluminium sheet for the wings, a decision Fujino says was based on manufacturability and ease of maintenance.
“Composite is light and strong, but the cost of fabrication was an issue for this size of aircraft. Impact damage from stones and hail — which is less critical on the fuselage — was also a consideration.”
The light weight and powerful twin engines, each with a thrust of 2050lbf, are responsible for some impressive performance figures. The aircraft’s takeoff distance is less than 4,000ft and landing distance less than 3,000ft. It climbs at a rapid 3,990ft per min and has a maximum cruise speed of 420 knots at 30,000ft. That’s around 30-40 knots faster than other aircraft in its class despite a similarly sized engine, thanks mainly to clean aerodynamics, Fujino says.
Another factor is the HondaJet’s maximum cruise altitude of 43,000ft. “That gets you above the traffic, there is less effect from the weather and you save fuel,” he says.
The HondaJet’s range with four occupants is quoted at 1,180nm (2,185km) and tests have shown that it typically consumes 165 gallons (750 litres) of fuel on a flight of 600nm (1,111km), a claimed improvement of 15-20% on the class average.
High pilot awareness
Honda revealed enhanced avionics and cabin management systems at EBACE. The flight deck includes a customised Garmin G3000 all-glass avionics system with three 14in landscape format displays and dual touch-screen controllers for avionics control and flight plan entries.
In a new split-screen format, 60% of the primary flight displays are allocated to flight information including synthetic vision, and 40% to pilot-selectable features such as system data and maps. This provides a level of situational awareness unique in a light jet, Fujino says.
Back in the cabin, Honda has adapted to the rapid changes in cabin electronics by removing the planned pull-down display units above each seat. Instead, passengers can use their mobile devices to access entertainment (there are three available tiers of audio, video and IFE), view real-time flight information, and control lighting, temperature and electrochromatic window shades.
The company is aiming squarely at the owner-operator and specifically the owner-pilot, for whom the quality of the flying experience is important. In this level of aircraft the cockpit is part of the interior space, so maximum space is the first thing potential owners look at. A close second comes cabin comfort, and with this in mind Honda has built in some unusual features.
For example, the four main seats move on a multiple axis, so can slide inboard, creating extra elbow room, as well as forward and back. “You don’t need an aisle in mid-flight,” Fujino points out.
A well appointed, fully private aft lavatory has a hard surface vanity unit and a patented solid door, with panels that drop down to the centre floor level on locking. This is much more than an emergency facility and recognises what can be an emotive issue especially for female travellers, Fujino says. He feels designers of aircraft flying two to three-hour segments have not paid sufficient attention to this area in the past.
The proof-of-concept aircraft had flown more than 500 hours as of May 2012, and six test planes have been built in all. Honda would have got its regulatory approvals this year if an engine had not suffered minor damage during an on-ground ice ingestion test, the company admitted at last year’s NBAA.
This setback meant the one-piece blisk, which incorporates rotor disc and blades, had to be redesigned. Fujino emphasises that the local reinforcement that was needed did not add significant weight and created no performance issues, merely delaying certification.
Honda is now receiving production parts into its manufacturing facility at Piedmont-Triad International Airport in Greensboro, North Carolina, ready to begin assembly of the first production models. There is a suggestion that the aircraft may receive interim certification, with engine icing performance still awaiting final approval, depending on how soon it can complete tests.
A full-motion flight simulator being developed by FlightSafety International will be installed on the HondaJet campus in the first half of 2013, and an MRO facility is also being built alongside the production line and R&D centre.
Fujino: I’ve got one more design in me before I retire
Long-term value
The HondaJet’s $4.5 million price tag makes it a good deal more expensive than the Phenom 100 or Citation Mustang, though below the M2. Operating cost will be in line with its rivals, says Fujino. “But we feel our aircraft could hold its value better.” He believes the level of product support from Honda could also be a clincher for many prospective owners.
The aircraft will be sold via a dealer network, a route Honda is familiar with from the car industry. The company has appointed five dealers in the US, one in Mexico and three in Europe.
Of 100-plus orders to date, more than 60% are from the US and 35% from Europe, though Fujino expects European customers ultimately to account for half of sales. Although the main target is the owner-operator, he feels there is potential for fleet operators and the charter sector. The operating efficiency and environmental credentials of the HondaJet will appeal especially in Europe, where he is encouraged that overall fleet growth is still in double digits.
Fujino anticipates 50 aircraft will roll off the production line in the first year, then between 75 and 90 in year two before Honda ramps up to full capacity of 100 in year three.
Only when US and European orders have been delivered, in two to three years, will Honda start to look at markets such as China and Brazil, where it is in preliminary discussion with potential partners.
Lessons from car assembly
What can an aircraft OEM learn from its experience in the in the cutthroat motor industry? Analysts have not been slow to point up the differences between the automotive culture, with its emphasis on continuous improvement and regular changes in the supply chain, and the tightly regulated world of aircraft manufacture.
While the technology is very different and the life cycle much longer than the automotive industry’s two to three years, there is room for improvement in aircraft design and fabrication techniques, Fujino says.
Carmakers work to a mantra of continuously improving part quality without increasing the cost. Honda’s experience of mating parts in car cabins for a perfect fit is something it looks forward to bringing into the business jet environment.
Nor does Fujino plan to stop at his first HondaJet. “I’ve got one more design in me before I retire,” he promises.