Powering Up The Next Generation Of Turboprop Aircraft

Four turboprop engine manufacturers dominate the current regional airline arena. The turboprop order book as of July 1 stood at 654 aircraft, 550 of them ordered by airlines and the remainder by leasing companies. Data from U.K. consultant AISL shows that Pratt & Whitney Canada leads the pack with a 66 percent share of the engine backlog, largely due to the success of the ATR 42 and ATR 72, two aircraft types which between them account for just over a quarter of all the orders.

Next in line is GE Aircraft Engines (GEAE), with 16 percent of the engine backlog. GEAE's leading application is the Saab 340. Garrett has almost a 12 percent share, with the Metro the leading type. Last comes Allison Gas Turbine Division of General Motors, but it is new to the field - though certainly not to engine manufacture. Allison's future in the regional airline sector is tied to the Saab 2000, and if that aircraft proves a successful follow-on to the 340, the engine manufacturer has the potential to establish itself in this sector.

A large number of older turboprop engines are still in regional operation. The Rolls-Royce Dart, now out of production, is in service on almost 600 F27s/FH227s, more than 250 BAe 748s, and 150 YS-11s - plus quite a few Viscounts and other types. Rolls-Royce laid the foundations of this market in the 1950s, but the company's strategy in the 1980s in the civil field established itself as one of the big three turbofan manufacturers, and turboprop activities have taken a back seat. The company dropped its proposed RB550 turboprop, an engine which would have been aimed at the 60- to 80-seat airliner market.

Another success story among older engines is the PT6A, which first ran in 1959 and is still in service in large numbers. Its growth from the original 500 shaft horsepower (shp) to several current versions of around 1,000 shp, for example in the Beech 1900, underlines the long commercial life to be expected from a successful design.

Auxiliary power units (APU) are likely to be seen increasingly on commuter aircraft. Saab officials admit privately that it was a mistake to design the 340 without one, though an optional package is available. The company has included an APU in the Saab 2000, chiefly in response to customer demand from the United States. The BAe ATP has a Garrett APU for air conditioning and engine-starting - the Brasilia, Dash 8 and Fokker 50 are among aircraft with an...