NBAA 2006: Engine giants power up for growth

Honeywell unveils turbofan for super mid-size sector while GE Honda breaks into booming very light jet market

Engine manufacturers are responding to growth in the business jet market, with Honeywell unveiling a new 10,000lb-thrust (44.5kN) turbofan aimed at the super mid-size sector and securing a launch customer for its 5,000lb-thrust TFE731-50. The GE Honda Aero Engines joint venture has broken into the light jet market, with HondaJet and Spectrum Aeronautical selecting its 2,000lb thrust-class HF120.

The HTF10000, a 25% geometric scale-up of the HTF7000, is provisionally aimed at certification in 2010-11 and entry into service around 2012-13. Honeywell has specific potential applications, but declines to identify them. "We couldn't have gone this far without serious interest," says advanced technology vice president Bob Smith. "But we're not launching an engine. We're trying to get to a TRL [technology readiness level] of 6 or better."

Capable of either a pneumatic or electric start, the HTF10000 builds on technology programmes that reduce the number of bearings to 11, versus 13 in the HTF7000, and offer a more efficient fan design.

Performance targets include Stage 3 minus 30EPNDB, Class 5 emissions and "competitive" reductions in fuel consumption. The engine will have a 1.04m- (3.4ft) diameter, wide-chord forward swept titanium fan with composite containment case and composite, individually insertable stators. Bypass ratio is expected to be "4.5:1 plus", and overall pressure ratio (OPR) in the "high 30s at least". The HTF7000 has a 0.87m fan, 4.4:1 bypass ratio and 28.2:1 OPR.

Smith says the design could eventually be scaled back down to produce future engines in the 5,000lb-thrust range, but adds: "We're not looking at anything beyond 10,000lb. That's where we will top out." Honeywell's TFE731-50, meanwhile, will power the Hawker 900XP, the improved fan and compressor giving up to a 7% range increase over the 850XP's -5BR for standard day take-offs and up to 24% "hot and high".

With the retrofit market in mind, the digitally controlled TFE731-50 is compatible with the -5BR inlet duct, nacelle and thrust reverser. Potential applications include the -5BR-powered Hawker 800, Learjet 60 and Falcon 20 and 900.

GE Honda, which declines to comment, is expected to run its HF120 next year, leading to certification in 2009 and entry into service on the HondaJet and Spectrum 40 Independence in 2010. A derivative of the HF118 powering the proof-of-concept HondaJet, the higher-thrust HF120 has a 470mm- (18.5in) diameter, wide-chord swept fan two-stage low-pressure (LP) compressor Honda-developed counter-rotating high-pressure (HP) compressor based on a titanium impeller design reverse-flow combustor lined with high temperature Hastelloy and single-stage HP and two-stage LP turbines.

Source: Flight International