Proven Technology Drives Continuing Success of GE's CF34 Engine Family

September 26, 1995 -- LYNN, Massachusetts - The most recent addition to GE Aircraft Engines' (GEAE) family of small turbofan engines, the CF34-3B for the long-range Canadair Challenger 604, achieves its performance improvements of higher power and improved fuel economy by incorporating new, yet proven, technologies.

The result is an approximately 3 percent improvement in specific fuel consumption, contributing directly to the 4,000 nautical mile range of the Challenger 604. Other operational improvements include a faster rate of climb, more cruise thrust, and shorter hot/high takeoff field performance.

GEAE's evolutionary approach to CF34 engine family development has met with great success since the first CF34, the -1A, helped launch the Challenger 601 in 1983 and continues with the latest successful development of the -3B.

Lloyd Thompson, general manager of GE's Small Commercial Turbofan Department, said, "GEAE achieved the -3B's performance improvement by incorporating several new features proven on other GE engine programs, including a redesigned, single-page, stage 1 compressor blisk and improved turbine cooling efficiency. Other features include better clearance control, higher turbine efficiency, and the low emissions combustor and turbine blade serpentine cooling introduced on the -3A1 model for the Challenger 601.

"Over the course of the CF34 family evolution, the introduction of new materials and improved design and manufacturing techniques has helped the engine achieve a continuous progression of performance improvements that bring real value to our customers, and the -3B continues that successful approach."

The new CF34-3B stage 1 compressor blisk is machined from a single forging as an integral unit, using GE manufacturing technology that has been proven during millions of hours of flight service in other GE engines. The integral blisk provides improved aerodynamic characteristics for increased airflow and efficiency. it is a key contributor to the Challenger 604's 5-to-7 percent better climb performance, 3 percent lower fuel consumption, and improved hot day performance and increased range and payload.

The GE patented serpentine-cooled turbine blade cooling design incorporates advanced ceramic core and blade casting manufacturing technology. This turbine blade cooling technology pays dividends in longer parts life, improved fuel consumption and lower operating costs.

The CF34 low emissions combustor dome design optimizes air distribution and increases primary zone burning efficiency. Primary and secondary combustion zones are designed to allow better cooling and lower combustor metal temperatures. The result is a "clean and green" engine with lower carbon monoxide and unburned hydrocarbon emissions at low power setting, decreased oxides of nitrogen at thigh power and cruise, and reduced fuel consumption.

The successful evolution of the -3B began with the -1A, a commercial derivative of the TF34 military engine, developed specifically for the Challenger 601. On entering service a dozen years ago, the -1A offered operators an engine with reduced noise, improved materials, modular construction, and containment features. The -3A model, introduced four years later, provided extended range and higher payload at high/hot conditions. The Challenger 601 and Canadair Jet's current engine, the CF34-3A1 added longer life materials, improved maintainability, and the low-emissions combustor.

"We will continue to utilize technologies developed GEAE's broad range of engines. By using proven technologies to advance the capabilities of our products, we can make significant gains in shortening program timing, reducing cost, and reducing risk," Thompson said.

"Because of GEAE's broad product line, we believe we have a distinct advantage over our competition when it comes to the size of the technology menu from which we can choose. Whether it's advanced fighter engine technology, or cutting edge technologies for airlines propulsion systems such as our GE90, we can rely o having a very broad base of demonstrated technologies to evaluate for their potential payoff for our corporate and regional airline customer," he said.