As small jets become increasingly common, both for business and personal transportation, perhaps it is natural that Honda is interested in airplane and aircraft engine manufacturing.
After all, Ford, another company that brought automobiles to the masses, bought into the airplane business in 1925, just as air transportation caught the public imagination. Honda may see personal aviation as a natural next step.
It has been a step characterized by secrecy and exceedingly cautious release of information, however. In the beginning, the HondaJet didn’t exist. Indeed, Honda wouldn’t acknowledge its existence until its first flight last December, when the company shrugged it off as strictly a technology exercise and a test-bed for its HF-118 fanjet engine. No plans for airplane production, Honda spokesman Jeffrey Smith insisted.
Then the HondaJet got its first public exposure at Oshkosh in July. Slightly smaller than a Cessna CJ1, it generated an astonishing amount of interest, prodding Honda Chairman Takeo Fukui to say shortly after the show that Honda just might certify the airplane, after all.
The HondaJet is innovative in many ways, not all of which are visible from the outside. For example, the company has done highly sophisticated studies of airflow dynamics around the engine pylons and along the fuselage. The resulting pylon shape is almost wing-like. An airfoil thicker than one might expect is due both to the torque strength needed for the wing to support engine thrust and to Honda’s conclusions about natural laminar flow. Honda Vice President Michimasa Fujino said at Oshkosh that laminar flow is maintained almost two-thirds of the way back over the wing’s chord. The unusual, sculptured shape of the airplane’s nose also keeps laminar flow attached beyond what has been achieved previously, he said.
Honda has put a lot of time and effort into learning more than any other organization, apparently including NASA, about laminar flow, its control, and its effects on aerodynamic efficiency. It will be interesting to see what comes of that study, as more veils of Honda secrecy are shed.
Honda claims that, compared to other jets its size, its jet offers superior fuel efficiency and a remarkable amount of cabin space. The engine position, above the upper surface of the wing, reduces high-speed drag which, in turn, increases cruising efficiency. That layout also eliminates the need for engine mount structure in the fuselage, allowing some 30% more cabin volume than in other jets of similar size.
The fuselage is built of a lightweight graphite composite and reinforced honeycomb structure, which also helped create a lightweight fuselage with more interior space, Fujino explained. The honeycomb sandwich enables sophisticated compound curves to be constructed, especially important for the laminar flow nose, he said. The main wing is assembled from large skin panels formed from single sheets of aluminum. That provides a smoother surface than conventional wing construction and contributes to the success of Honda’s proprietary laminar flow airfoil, significantly improving aerodynamic performance, he said.
With the nose design also generating laminar flow, the combination of features, along with Honda’s fuel-efficient HF118 turbofan engine, achieves fuel efficiency some 40% better than conventional aircraft, Fujino claims. “The constant cross-section of the cabin can be easily extended to satisfy future fuselage stretching,” he added, subtly encouraging even more speculation about Honda’s long-term aircraft business plans.
The HondaJet is fitted with a Garmin G1000 glass cockpit with an integrated avionics system and autopilot function, anti-icing equipment, and most other systems normally found in small business jets these days. The prototype is scheduled for some 200 hours of flight testing “to demonstrate and verify the operability and performance characteristics of its various systems,” Fujino said. Honda now admits that it began research into compact business jets in 1986, initially using engines provided by other manufacturers. That the current prototype is powered by Honda’s own HF118 turbofan is described by Jeffrey Smith as “a significant milestone for the company and the industry.”
Early in the project, Honda conducted a five-city series of focus group interviews, indicating to the company that there is a demand for “comfort, in particular a large cabin, as well as high fuel efficiency,” Fujino said. “The HondaJet is designed to satisfy these needs.”
One of Honda’s websites features a 10-minute video (the “long version”) of the airplane in flight and shows off mock-ups of two HondaJet magazine ads featuring the words “Up, Up and Away.”
Will we ever see those mock-up magazine ads in print? Don’t bet against it.