EBACE 2011: Honda Aircraft well on way to HondaJet certification
As the HondaJet enters the final phases of FAA and EASA certification, Honda Aircraft employees are preparing for volume production and first deliveries, scheduled to begin in the third quarter of 2012. The 263,400-sq-ft Honda Aircraft production facility in Greensboro, North Carolina, opened in April. The customer delivery center is nearly ready and the first FAA-conforming HondaJet (F1) has expanded to the full high-speed and high-altitude envelope during more than 100 hours of flight testing since it first flew on Dec. 20, 2010. The conforming GE Honda HF120 turbofans for F1 were delivered to Honda Aircraft late last October.
The $4.5 million, seven-seat HondaJet features Garmin’s G3000 avionics suite with two touchscreen controllers. The private lavatory features an externally serviceable flushing toilet. The external aft baggage compartment holds up to 57 cu ft of luggage, and another nine cubic feet are available in the nose compartment.
Because the conforming jet is aerodynamically much cleaner than the proof-of-concept prototype and the 2,050-pound thrust HF120 is more powerful than the POC’s Honda-made HF118 engines, the latest version climbs faster, flies faster and burns less fuel. During flight testing, the FAA-conforming HondaJet F1 has flown at a maximum speed of 425 knots (true airspeed), climbed at 3,990 fpm and on April 27 reached the maximum operating altitude of 43,000 feet. The 425-knot figure is five knots faster than the original estimate, according to Honda Aircraft president and CEO Michimasa Fujino.
“It’s a very quiet aircraft,” he said, even without insulation installed. The unique over-the-wing positioning of the engines helps minimize external noise but also eliminates engine vibrations transmitted through the fuselage.
Fujino designed the engine inlets to maximize efficiency and minimize noise. Instead of using a composite-honeycomb sandwich for the nacelle, he selected laminated composites, which further reduce noise. The honeycomb material tends to amplify vibrations, he said, “and resonance damping is not good,” thus requiring more insulation, which adds weight. The laminated composites thus end up being lighter and quieter. The length of the inlet leading edges is also critical. Too long, and efficiency suffers, but too short and noise is a problem, so Fujino optimized this element as well.
The next HondaJet to fly will be F2–the third conforming jet. Honda Aircraft has completed power-on testing and is performing function testing on F2 in preparation for its first flight this summer. The second conforming jet has been undergoing structural testing, which is being done on the full airframe and quite a complex process, Fujino said.
Honda Aircraft technicians are busy installing systems on the fourth conforming HondaJet (F3), which will also join the flight test program. The fifth jet (ST2) is slated for stress and fatigue testing, then the final test jet (F4) is expected to fly in spring 2012 and be used for cabin systems and function and reliability testing.
Some of the interior will be installed on F3, but it will still carry test equipment and sensors. So the first HondaJet with a production-conforming interior will likely be F4. “With a total of six aircraft planned to support the certification process,” said Fujino, “we believe we will have the optimal resources to meet both our flight test program needs and our certification schedule.”
While most of the HondaJet structure will be built at the Greensboro facility, UK-based Hampson is manufacturing the aluminum empennage. The composite fuselage, made of a honeycomb sandwich and stiffened panels, is built in two halves in molds that are cured in an autoclave. Honda Aircraft earlier had planned to have wings built by a third party but will manufacture the first 30 to 40 wing sets in Greensboro, according to Fujino, then may move wing manufacturing to another company. “We’ll do what’s best from a cost and quality standpoint.”
Fujino praised the Honda Aircraft employees in Greensboro, noting that each new jet is being built better and faster as they climb the learning curve. The parts count of the production-conforming HondaJet is much lower than in the POC.
An unusual feature for a Part 23 light jet is bleed-air anti-/de-icing for the HondaJet wings; most light jets use pneumatic boots but, said Fujino, “It’s almost impossible to attain laminar flow with boots.” The horizontal stabilizer is protected with an electromechanical expulsion de-icing system.
So far, HondaJet F1 has flown about 650 unique test points. The four flight-test HondaJets will be flown about 1,500 hours during the certification program, and F1 has flown about 30 percent of the hours it will fly for certification. “We don’t have any big surprises,” said Fujino. “The aerodynamic characteristics are very close to our calculations and performance is slightly better than our conservative estimates.”
Testing of systems and components continues. The two static test HondaJets will eventually be tested to the equivalent of three lifetimes, with each life being 20,000 flight hours. By the time the HondaJet is certified, testing to one lifetime should be completed.
The FAA is working closely with Honda Aircraft during the final phases of certification and is encouraging Fujino to obtain the production certificate soon after receiving the HondaJet’s type certificate. This means more work up front to finalize and document manufacturing and quality control processes, but that is work that needs to be done anyway. “It’s a very stringent process,” said Fujino. “We cannot compromise quality or safety.”
Honda Aircraft is using SAP software to help manage all of its IT systems and processes. The SAP system, he said, “is very difficult to implement, but once implemented, it’s a very strong tool. We can manage time, we can manage cost and we can manage each configuration of the aircraft. It’s probably the most advanced integration, even compared to the entire Honda [company].”