Mitsubishi picks GTF to power new jet

 - November 5, 2007, 9:27 AM

Mitsubishi Heavy Industries last month received board authority to offer to potential customers the proposed MRJ regional jets, powered by an engine line known as the Geared Turbofan under development by Pratt & Whitney. Mitsubishi has begun formal talks about possible collaboration with Boeing on the project, scheduled for industrial launch by the end of March.

Meanwhile, the company plans to conduct “robust” marketing activities, negotiate details with potential partners, establish a sales finance program and develop an operational structure. Mitsubishi continues to deliberate over the possibility of establishing a new division to oversee development, manufacture and marketing of the pair of airplanes, expected to carry 70 and 90 passengers, respectively, in standard airline configurations.

The MRJ design arose from studies conducted by Mitsubishi in cooperation with the Japan Aerospace Exploration Agency. The 90-seat version, scheduled for certification first, by 2012, would measure 117.5 feet long and feature the same 101.4-foot wingspan planned for the 70-seater. Mitsubishi plans to build the 9.5-foot-diameter cylindrical fuselage out of composites it helped develop for the Boeing 787 and use fly-by-wire flight controls.

Perhaps most notably, the airplanes could well present Pratt & Whitney with its first application for its Geared Turbofan (GTF). The technology centers on a gearbox just behind the main fan that allows it to operate independent of the low-pressure compressor and turbine, resulting in a 12-percent fuel burn reduction and a lower fan speed for less noise. Pratt & Whitney has spent more than $1 billion on the project over the past 20 years, including $12 million on a facility in Middletown, Conn., dedicated to testing the fan drive gear system.

Pratt & Whitney plans to begin full-scale ground testing on a 30,000-pound-thrust GTF demonstrator this month and flight testing some time near the middle of next year. Meanwhile, the company continues work with Germany’s MTU Aero Engines on a scalable common engine core technology for airplanes ranging in capacity from 90 to 200 passengers. The common core components include development of a new high-pressure compressor and high-speed, low-spool turbine technologies.

Targeting maximum takeoff weights of 89,500 pounds for the MRJ70LR and 94,100 pounds for the MRJ90LR, Mitsubishi will need an engine capable of producing 14,500 pounds of thrust for the 70-seater and 17,100 pounds for the 90-seater.

Design targets place range at 2,110 nm for the MRJ70LR and 1,790 nm for the MRJ90LR, cruise speed for both airplanes at Mach 0.78 and takeoff field lengths at 5,640 feet and 5,810 feet.