Raytheon Aircraft is working to improve the field performance of its newly certificated Premier I business jet, having missed the promised 915m (3,000ft) take-off distance by a wide margin.
The current take-off distance of 1,155m is the result of a higher than expected stall speed, says Jack Hulsey, vice-president of development for the Premier. Stall speed is "up 6-7kt [11-13km/h] over windtunnel predictions". The entry-level jet meets other performance guarantees, he says.
In a bid to reduce take-off distance "below 3,500ft", Raytheon will increase engine thrust by 100lb to the full 2,400lb (10.7kN) available from the Premier's Williams-Rolls FJ44-2 turbofans. Wing changes will be tested in an effort to reduce stall speed. "The biggest hit was in stall speed," says Hulsey, "and reducing stall speed will make the biggest difference."
There has been "no fallout" in the Premier orderbook from the longer-than-advertised take-off distance, says Raytheon chairman Hansel Tooks. The company has orders for over 300 aircraft and the $5.26 million entry-level jet is sold out to the fourth quarter of 2005.
Tooks says Raytheon is looking at increasing production beyond the planned 60 a year to make aircraft available sooner. But a decision on accelerating production "is not imminent", he says.
Certification of the Premier for single-pilot operation and for flight into known icing is expected before customer deliveries begin in May/June. Hulsey says talks are underway with Williams to find a way to overcome the 18-20kt drop in airspeed that occurs when de-icing is activated, the bleed air offtake reducing engine thrust.
Source: Flight International
