The first General Electric GE90-powered Boeing 777 resumed certification flight-testing on 20 July, following rectification of a fan problem discovered during ground-based bird-strike tests earlier this year. New fan-platform spacers have been fitted to existing test and production engines, following validation tests in early July.
Compressor surge problems, were encountered in early May, but these were solved by modifying the software, which controls the variable geometry vane schedule.
Boeing and GE say that they still hope to deliver the first GE90-powered 777 to British Airways in September.
Meanwhile, GE is working on the possible development of a 465kN version of the GE90, which could be slightly de-rated to power the recently launched 777-300 "stretch". To achieve the higher thrust levels, the core may be "de-staged", but the engine would retain the existing fan and low-pressure system.
In addition, the company will test a 425kN version of the GE90 in the first quarter of 1996. This would be pitched at heavier B-market versions of the 777. The initial A-market GE90, capable of 410kN, but de-rated to 400kN, should enter service on a British Airways 777 in December 1996.
The GE90 has now completed over 13,500 endurance cycles and been operated for over 65h at thrust levels exceeding 445kN.
Ishikawajima Heavy Industries of Japan, will be a major partner in GE's CF34-8C turbofan programme. This 60kN engine has been selected to power the proposed Canadair CRJ-X stretched Regional Jet.
GE says that the CF34-8C may form the basis of a new family of engines in the 60-80kN class, with growth coming through the use of a new high-pressure compressor, based on the military F414 engine, a new low-pressure turbine, a multi-hole combustor as used on the GE90 and F414, and a larger diameter, wide-chord fan.
Lockheed Martin has selected the CF6-80C2 to power the C-5D, which it is offering the US Air Force to satisfy the Non-Developmental Airlift Aircraft requirement. The 220kN CF6-80C2s would improve the C-5D's take-off performance and reliability.
In the helicopter engine market, testing of the gas-generator core of the growth derivative T700/T6E turbo-shaft engine will begin in September and the first complete T700/T6E will go on test in 1996. Developed jointly by GE, European Gas Turbines, Alfa Romeo Avio and FiatAvio for the NH90 helicopter, the T700/T6E is rated in the 1,790kW (2,400shp) class and is expected to form the basis of a family of turbo-shaft and turboprop engines.
On the military side, technological advances developed in the F414 programme, such as single-crystal turbine blades and a lightweight composite duct, have been incorporated in the F404-402, the newest model F404 for the McDonnell Douglas F-18.
The company is heavily involved in the US Department of Defense's three-phase, Integrated, High Performance, Turbine Engine Technology (IHPTET) initiative, and the Allison/GE team has been selected to act as major-contractor for demonstration of the Phase II IHPTET goals.
Source: Flight International
