Page 8 - Demo

With the HondaJet’s OTWEM con guration, the pylon acts as an aerodynamic surface that achieves lower wave drag at higher transonic speeds.
When provided the opportunity to fly the HondaJet at this year’s AirVenture Oshkosh, I approached it strictly from the perspective of a step-up owner-pilot who would be operating it single-pilot and with no prior jet experience. Honda Aircraft Company’s Flight Operations Manager and Chief Test Pilot Warren Gould, who hosted me on this test flight, has been involved in the initial development and f light test of multiple jets in his career at other OEMs. He said he was impressed with HACI’s approach to single-pilot ops.
“In the development phase, they built multiple mock-ups and spent a lot of time gathering pilot input. This is most pilot involvement I’ve ever seen on a development program,” Gould said. “It is an extremely pilot-centric aircraft, with tremendous thought given to simplicity, workload and ergonomics.”
The Walkaround
Before our f light, Gould took me on a detailed walkaround to point out the features that make the HondaJet a formidable light jet, as well as an ideal owner-pilot platform. The obvious one
6 • TWIN & TURBINE
is the over-the-wing-mounted engines, or as HACI calls them, OTWEM. Initially conceived by Fujino, the company adopted the OTWEM for three primary reasons: First, mounting the engines on the wing provided more space in the fuselage by eliminating the carry-through structure that would normally be located in the rear part of the fuselage. Engine accessories are also encased in the pylon instead of the empennage. All of this translates into a roomier cabin, lavatory and aft baggage compartment.
Second, it contributes to the aerodynamic efficiency of the airframe because the pylon design itself acts as an aerodynamic surface that achieves lower wave drag at higher transonic speeds. Thus, high-altitude cruise efficiency is actually greater than that of a conventional rear-fuselage engine- nacelle configuration. Finally, engine noise and vibration in the cabin is reduced as the engines are now located further away from the cabin.
Another noticeable feature is the aircraft’s super-smooth natural laminar
flow wing. The wing is built from a single 2,000-pound piece of aluminum that is milled down to about 70 pounds. There are no rivets to interrupt flow, resulting in a low-drag, highly efficient airfoil. The tall winglets attached to fairly short wings add effective dihedral to provide lateral stability in addition to acting as a lifting surface to increase climb and cruise performance. The wet wing is connected to a bladder tank in the fuselage and all interconnected and automatically managed. Single-point refueling is accomplished through gravity fill rather than pressure.
The fuselage is all composite, giving it an extremely smooth, sleek appearance. The bulbous nose of the aircraft – which observers either love or hate – is an aerodynamic marvel as well. Using a natural laminar flow shape, the nose reduces drag and wing noise, as well as providing ample leg and elbow room in the cockpit.
Keeping with the theme of reducing pilot workload and increasing safety, the aircraft’s de-ice systems are all managed and activated automatically with no
October 2017