NBAA Convention News

HF120 advances toward FAA tests

 - October 1, 2008, 11:36 AM

GE Honda Aero Engines has started building the first HF120 engine for FAA certification testing scheduled to begin early next year.

Hardware for this engine began arriving at General Electric’s Lynn, Mass. facility last month, keeping the program on track for certification later next year. Honda Aircraft’s HondaJet and the Spectrum Aeronautical S40 Freedom are launch customers for the 2,095-pound-thrust HF120.

An HF120 will make its first flight on Honda Aircraft’s testbed CitationJet in next year’s second quarter, according to Atsukuni Waragai, president and CEO of Honda Aero and executive vice president of GE Honda Aero Engines. Honda Aero is the Burlington, N.C.-based Honda subsidiary that eventually will assemble, test and support the HF120.

During the initial phase of the HF120 program, engines will be built at GE’s Lynn facility under a GE production certificate. Honda Aero will obtain its own FAA production certificate in 2010 and become an FAA-approved repair station. Then in late 2010 and early 2011, the HF120 assembly line capability will be transferred to Honda Aero’s new facility, Waragai said.

So far, during the HF120 test program, the GE Honda Aero team has done 10 builds of the full turbofan engine and nine builds of the core engine, according to Bill Dwyer, GE Honda Aero president. “We’re methodically marching along,” he said. One reason for the different builds is that on smaller turbofan engines, it’s difficult to add instrumentation to make critical measurements without affecting the engine’s performance. Several builds are needed to collect data, while other builds are focused on optimization of the design.

Testing has included verifying the design, checking aeromechanics of the blades and flow path, vibratory cycles and high-cycle fatigue, verifying thrust levels, fuel burn and emissions, and testing rotor dynamics and bearing systems. GE engineers who worked on the GE90 and GEnx programs helped evaluate leakage flows in the HF120, Dwyer said, “giving us significant confidence going into the certification program.”

The program will involve seven engines made from 13.5 sets of complete engine hardware. “Some of that is spare hardware,” Dwyer said, explaining why the parts count adds up to 13.5 engines. Some hardware will be tested to beyond FAA certification minimums, he noted, including a 15,000-cycle test before the engine’s entry into service. He added that the 10 turbofan and nine core builds so far are more than are typical for a new engine program. Honda’s ability to build prototypes rapidly allowed the joint company to perform much more verification testing, he said, “and go into the program with much lower risk and a lot of confidence relative to performance and outcomes.”

Waragai provided an example of how designers at GE and Honda worked together to optimize the HF120 design. “We had a competition for the fan design,” he said. But instead of just selecting the best fan from either team,  “we combined them and got a much better fan,” he said.

With regard to HF120 performance, Dwyer said, “Our goal is to exceed the promises made to customers in thrust, fuel burn and weight. Right now we’re on track and we feel good going into the conforming certification program.”

Once the engine enters service, there will be two overhaul centers: GE Lynn and Honda Aero in Burlington. The 5,000-hour TBO means that engines will not need overhauls until years after customer deliveries of HondaJets and Freedoms begin in 2010. GE’s existing service center network will provide between-TBO service.

As the HF120 program matures and nears certification, GE Honda Aero continues to evaluate additional members of this engine family. “It’s fair to say we’ve looked at that,” Dwyer said. “Usually, successful engine programs have lots of siblings. We continue to study the right next family member.” Meanwhile, he concluded, “development is at full throttle.”