GENERAL ELECTRIC is developing two new versions of its CT7 turboprop family, a CT7-9+, which will be certificated later this year, and a more ambitious CT7-11 variant which has been timed for 1999.
GE says that the growth programmes will meet the requirements of current CT7-powered, aircraft for better hot-and-high performance as well as for operations at increased growth weight. The additional performance will also bolster the CT7 family against increasingly stiff competition from manufacturers AlliedSignal and Pratt & Whitney Canada.
In the first stage of the growth programme, a new centrifugal compressor stage is being added to the T700-based CT7 to produce almost 75kW (100shp) extra take-off power at sea level. More fundamental modifications are being made to produce the -11, which will incorporate an advanced axial/centrifugal compressor. The -11 is expected to be rated at around 1,450kW and will be available in production standard from 2000.
The CT7 family is used on the Saab 340, CASA/IPTN CN-235 and Let L-610G, as well as the newly developed Sukhoi S-80 utility aircraft. All these manufacturers have requested additional performance margins, particularly for hot-and-high conditions. CASA is considering the growth series for the heavier CN 235-300, while IPTN is similarly looking for higher power for the CN 235-330.
P&WC says that the PW150A engine, officially selected in June 1995 for the Bombardier Dash 8-400 regional transport, is on schedule for a first run in June 1996.
Source: Flight International
