BAe Jetstream 31 / 41

BAe Jetstream 31 / 41

The British Aerospace Jetstream 31 and 41 are small twin-engine turboprop regional airliners seating 19 and 30 passengers respectively.

The Jetstream's history begins during the 1960s. The British aircraft manufacturer Handley Page wanted to stay independent of the big two British aerospace companies Hawker Siddeley and BAC (British Aircraft Corporation). It had only limited financial resources, however, and therefore decided to develop a small airliner, the HP.137 Jetstream, seating 12-18 passengers. It was targeted at the US market for commuter airliners and corporate aircraft. The first prototype flew as 'Jetstream Mk.1' with Turboméca Astazou XIV turboprops on 18 August 1967. At that time Handley Page had collected a total of 165 orders and commitments. Soon, the US Air Force ordered eleven aircraft with Garrett AiResearch TPE-331 engines as C-10A (or 'Jetstream 3M').

The Jetstream had a pressurised fuselage so that it could fly higher than non-pressurised competitors. To attain a high cruise speed HP spent much attention to streamlining. This resulted in the Jetstream's long distinctive nose. The aircraft has a low wing and a fuselage with a rather small cross section. To make it possible for (not too tall) passengers to stand up in the aisle, the cabin floor was lowered so far that the main wing spar had to run over the floor. Passengers and the stewardess had to take good care not to stumble over it.

Because of problems with the Astazou XIV engines, the programme suffered delays and development costs soared. Handley Page had to pay the bills of its suppliers but didn't receive payments from customers waiting for delivery of their aircraft. The airframer invested in an improved version with Astazou XVI engines as Jetstream Mk.2 (also named 'Jetstream 200') but development of the Jetstream 3M stopped after the USAF cancelled its order because Handley Page couldn't meet the promised delivery dates. In 1970, Handley Page collapsed under its financial burden, after building 35 Jetstreams.

Scottish Aviation, which already produced the wings, took over the production of the complete aircraft. Soon, the Royal Air Force ordered 26 Jetstream 201s as multi-engine trainers designated 'Jetstream T.1'. Fourteen were later modified as T.2 observer trainers for the Royal Navy.

Jetstream 31

Scottish Aviation became part of British Aerospace (now BAE Systems) in 1978. BAe decided to develop the aircraft further and started work on a new version with Garrett TPE-331 turboprops, the Jetstream 31. The test aircraft was a modified Mk.1 which first flew on 28 March 1980. The first production Jetstream 31 made its maiden flight on 18 March 1982. The CAA certified the Jetstream 31 on 29 June 1982.

BAe kept the structural changes compared with the early Jetstream models as minimal as possible. Most rework was needed for the installation of the TPE-331. BAe chose this engine over the Pratt & Whitney Canada PT6 because it was easier to install on the Jetstream's wing, although in the USA converted aircraft were flying with both engine models replacing the poorly performing Astazous. BAe fitted a new, four-bladed propeller and increased weights and range. The Jetstream 31 is also faster than earlier versions. Other changes incorporated an all-new cockpit and lower internal and external noise levels.

The Jetstream 31 proved popular among commuter airlines, especially in the USA as feeder aircraft flying to the hub airports of major airlines. Competing 19-seaters were the Swaeringen Metro and Beech 1900. Of these aircraft the Jetstream 31 was the only one offering three-abreast seating instead of two-abreast.

In 1985 BAe launched the Jetstream Super 31, also known as 'Jetstream 32', with more powerful engines, increased headroom for passengers thanks to redesigned furnishing panels and lower noise and vibration levels. It first flew in 1988 and replaced the Jetstream 31 as standard aircraft on the assembly line. Production continued until 1993, by which time 386 31/32s had been produced. Early in 2015 around one hundred Jetstream 31s and 32s are still in airline service.

Jetstream 41

A stretched version is the Jetstream 41, seating up to 30 passengers and competing with other 30-seaters like the Embraer EMB-120 Brasilia, Dornier Do-328 and Saab 340. It first flew on 25 September 1991 and certification followed on 23 November 1992. BAe delivered the first aircraft to Manx Airlines two days later, on 25 November.

BAe changed so much that the Jetstream 41 had to be certified as an all-new aircraft type instead of a version of the 31. The fuselage cross section was retained, but many other things were renewed. The 41 has a new wing-to-fuselage junction so that the wing spar did not carry through the cabin aisle any more. The wing has a lower position and a bigger underfuselage fairing with the advantage of extra baggage volume.

The propeller of the Jetstream 41 is five-bladed (instead of four-bladed) and has a larger diameter. Increased span at the root of the wing allows for the larger propeller and results in extra wing area. The wing also has a higher aspect ratio. The flight-deck has an EFIS (Electronic Flight Instrument System) and the seven-piece windscreen arrangement was replaced by a six-transparency alternative. The main undercarriage legs retract forward instead of sideways. BAe relocated the passenger door ahead of the wing. Furthermore, the 41 has a modified tail unit, including a larger dorsal fin.

The Jetstream 41 didn't match the success of its smaller forerunner. Because of the fierce competition on the crowded commuter aircraft market of the 1990s, BAe lost money on every aircraft it delivered. It built only a hundred Jetstream 41s and early in 2015 around 50 of them are still flying with airlines.

Jetstream 31 Specifications

Wingspan: 15.85 m (52 ft 0 in). Length: 14.37 m (47 ft 2 in). Height: 5.32 m (17 ft 5 in).
Empty weight: 4,360 kg (9,613 lb). Max. take-off weight: 6,950 kg (15,332 lb).
Accommodation: 19 passengers. Range: 1,260 km (680 nm). Cruise speed: 426 km/h - 230 kts).

Engines: two Garrett TPE331-10UG turboprops (701 kW - 940 shp).

Jetstream 41 Specifications

Wingspan: 18.42 m (60 ft 5 in). Length: 19.25 m (63 ft 2 in). Height: 5.74 m (18 ft 10 in).
Empty weight: 6,416 kg (14,144 lb). Max. take-off weight: 10,886 kg (24,000 lb).
Accommodation: 30 passengers. Range: 1,433 km (774 nm). Cruise speed: 482 km/h - 260 kts).
Engines: two Allied Signal TPE331-14GR/HR turboprops (1,259 kW - 1,650 shp).