Update- BAe Jetstream 31

The Jetstream is available in four versions, though BAe marketing executives feel that the 18-seat commuter version has the most potential as the only other competition in this sector is the Metro II and III and Beech 1900. The commuter version has a maximum range of 630 nm each with 18 passengers and full IFR reserves or can, for instance, operate six sectors of 135 nm each with 9 passengers without touching the browser. This is quite an achievement and also allows Jetstream to shape up viably in its corporate role, an asset most of its competitors do not possess. The commuter version books a high-speed cruise of some 260 kts, or 230 kts in the long-range cruise mode at 25,000 ft. At this altitude, the cabin is pressurised to 5. 5 lb/in or the equivalent of a comfortable 8000 ft.

The second configuration is as an executive shuttle where a company needs to move personnel on a semi-scheduled basis. In this arrangement, the Jetstream would seat 12 passengers and include a toilet, galley, coat closet and baggage stowage. With an IFR range of 950 nm and an en route cruise potential of over 300 mph, Jetstream could find a new market niche in this area, particularly in North America.

The third variant is the pure executive transport, with an lf=R range of 1150 nm and luxury seating for nine passengers with full galley/toilet/bag stowage. According to a 1981 FAA forecast, there will be a market for 3400 new turboprops in the US alone between now and 1990, BAe estimates that at least 700 of these will be for 19-seat commuter aircraft hence aircraft 04 will be retained by BAe for use as a North American demonstrator. BAe hope to sell nearly 60% of Jetstreams to this market.

The fourth suggested variant highlights the degree of flexibility inherent in the aircraft in that a full range of special missions, such as airway calibration work and survey can be undertaken with ease. Ultimately the Jetstream 31 will be purchased for use with the RAF and RN as a Jetstream replacement.

The basic airframe of the aircraft remains largely unchanged from its original design though the gross weight has been increased from 12,500 lb to 14,500 lb allowing additional fuel and payload carriage using the flat-rated 900 shp Garrett TPE331-10 turboprops. The Garrett engine was chosen as the design of a straight-through power plant better suited to the Jetstream wing design, in fact the raised thrust line is one of the contributing factors in the aircraft’s higher cruise speed than the earlier and more powerful Astazou-powered Jetstream. Time Between Overhaul is posted at 3000 hours though Garrett hopes to double this figure in the commuter role.

Much of the faster cruise speed is directly attributable to Dowty’s new composite four-blade propellor which uses Nasa developed supercritical wing technology to improve performance in takeoff and climb. This propellor rotates at only 1590 rpm as compared with 1750 rpm on earlier Garrett retrofits and 1800 rpm on the early Astazous resulting in less noise both inside and outside the aircraft.

As this is written the first Jetstream is being delivered to Mall Airways of Albany, New York State, the first of seven deliveries scheduled for 1982. Production will increase to allow delivery of 18 aircraft in 1983 and a further 25 in 1984, already received are firm orders and options for 18 aircraft from operators in the UK, USA, Germany, Norway and Latin America. The Scottish division of British Aerospace have wisely decided to peg annual production to 25 aircraft though if the market grew beyond current market projections, production could be raised to 35 units to satisfy the demand. Like every other aircraft (and industrial) project the Jetstream has been impaled by the current recession and has probably as one of its greatest assets, the fact that the aircraft has just become available rather than being launched into service, say two years ago. The world economies will recover, interest rates will come down, and people will make a lot of sense in hindsight.

The aircraft will ultimately be marketed in Australia and could certainly find a ready market as a Metro replacement. The British have always been renowned for their ability to build strong and relatively corrosion-free airframes, the Jetstream is no exception in this regard and coupled with flat-rated Garretts, a 230 kt cruise speed, long legs and the roomiest cabin of any similar aircraft the ‘new’ Jetstream 31 will undoubtedly find many examples wearing local registrations by the end of the decade.