General Electric Aircraft Engines Reportedly Courting Biz Av OEMs

Flushed with the marketing success of its latest CF34 turbofan derivative, the regional airline Dash 8, General Electric Aircraft Engines is reportedly courting at least one business jet airframe manufacturer to adopt the 14,000-pounds thrust-class engine.

GE's general manager CF34 programs, Frank Klaus, would disclose neither the identity of the OEM nor the proposed platform, but said talks were ongoing. Given the CF34-8C's design thrust and existing airline applications aboard Bombardier Aerospace's 70- and 90-passenger regional jets, it is safe to say the candidate airframe would probably be in the long range Gulfstream V or Bombardier Global Express class.

In the meantime, the CF34 is perhaps on track to outsell General Electric's other big winner, the 25,000-pounds-thrust-class CFM56 airline engine, built in partnership with France's SNECMA, if current order trends continue. As of mid September, GE had produced 806 CF34s for business jet applications in Bombardier's Challenger 601 and 604 airframes and another 800 for airline placements aboard Bombardier CRJ regional jets. At that time total orders for the CFM56 stood at more than 9,000 engines. However, GE's CF34 backlog this fall stood at some 4,000 orders, which is why the company believes the smaller engine could eventually eclipse the CFM56 in outright production.

GE is almost giddy with the success of the CF34 since the first civil variant of the engine, the 8,000 pounds thrust (nominal) Dash 1A, was spun off the TF34 military turbofan in the early 1980s for a birth on the Challenger 601. Since then, Dash 3 and 8 variants have joined the product line, the last specifically to power 70- to 90-passenger regional jets, and a Dash 10 derivative rated up to 18,500 pounds thrust has been extrapolated to power 100- to 110-passenger transports.

The phenomenal growth of the engine in thrust output and sales has been directly linked to the success of the small regional jet concept, pioneered by Bombardier with the CRJ. In addition, fractional ownership is also driving CF34 sales. "I don't believe we've seen the end of fractional yet," Klaus said. "We see a continuing bright future for it."

Current production engines include the CF34-3A for the Challenger 604 and CRJ-200, the Dash 8C for the CRJ-700, and the Dash 8C5 for the CRJ-900. Soon to join the assembly queue are the CF34-8D for the Fairchild Aerospace 728JET and its Envoy 7 business jet sibling and Dash 8E for the Embraer ERJ-170. In development are the big 18,500 pounds thrust Dash 10D and E models, slated respectively for the Fairchild Aerospace 928JET and Embraer ERJ-190.

Improvements to the CF34 over the years culminating in the present Dash 3A variant seen in the Challenger 604 and CRJ-200 include the addition of blisk technology to the compressor, many changes to the engine structure to support maintainability, and a new ignition system. The regional jet application resulted in 'airlinizing' or 'ruggedizing' the powerplant, just in time for the rigors of fractional ownership. "The engine was made more robust when it was introduced into the regional airline arena," Klaus told Show News, adding that average regional airline utilization is running at 2,200 hours a year.

Growing the engine from Dash 3 to Dash 8 configuration involved major changes to the CF34, tantamount to designing a new engine. (This was borne out by the $500 million investment necessary to certify the Dash 8.) "We kept the same high pressure turbine, but the compressor was changed from 14 stages to 10," Klaus said, explaining that "fewer stages equals higher air flow due to less drag across the stators." For the new compressor GE dipped into its military bag of tricks, adopting a derivative from its F414 military turbofan used in the Boeing F/A-18 fighter.

The fan for the Dash 8 series was enlarged to 46 inches in diameter, a two-inch increase from that of the Dash 3A, and new wide-chord blades were added, attached to the fan hub with pin joints as opposed to dovetails. Finally, a larger annular combustor was designed for the new engine, and the low-pressure turbine was simplified for a lower parts count.

"The payoff is 50% more thrust and 30% fewer parts," Klaus said.