August 05, 2013
Credit: ATR-72: ATR
Five decades after jets wiped out large Western propeller airliners, the turboprop is pushing back. Until the arrival of the much-heralded propfan, it will not recover the trunkline ground it occupied until the 1960s, but pressure is building to expand the turboprop in the role that it has held since then as a fuel-efficient, short-haul passenger aircraft.
By the 1970s, the largest Western turboprop airliners surviving in production carried only about 50 passengers at modest speeds and over short ranges. A move back up to 70 seats in the 1980s and 1990s was confronted by renewed jet development in that size range and even in the 50-seat category. Around the turn of the century, when aviation kerosene dipped to $37 a barrel, the turboprop airliner looked just about dead.
What a difference an eightfold rise in fuel prices makes. ATR is now straining to meet demand for the 70-seat ATR 72, which, more than its high-performance competitor, the Bombardier Q400, is optimized for fuel economy. And, amid a general upward drift in airliner sizes, ATR's engineering team is one of five that are looking closely at building turboprops with at least 90 seats. The Franco-Italian company reckons the world will buy 1,340 such aircraft over the coming 20 years and says all its major customers want 90-seaters.
Despite the general similarity in appearance of turboprop airliners, at least four of the designs have crucial differences in cross-section, power and multi-version seating. Whichever of the five proposed types go to market—and it is unlikely that all will—they should be well-differentiated products, supporting the manufacturers' pricing power.
The proposals also vary in timing and probability of launch. Ranked roughly by those criteria, the five projects are the Avic MA700; the Regional Transport Aircraft (RTA) of India's Hindustan Aeronautics Ltd. and the National Aerospace Laboratories; an aircraft from ATR; a possible stretch of the Bombardier Q400; and, least defined, the Korea Aerospace Industries DRA, backed by parts of the South Korean government.
Avic Aircraft's MA700 is due to go into service in 2018, but so far only with 78 seats. A longer version, the exact size of which is not yet fixed, will probably follow in the early-to-mid-2020s, if development is smooth. China's record in developing commercial aircraft is not reassuring. The ARJ21 regional jet by Avic spin-off Comac is seven years behind schedule, and the timetable for the successor C919 is close to missing its delivery target. But, having built the Antonov An-24 under license and then updated it twice as the MA60 and MA600, the Avic engineers have learned to crawl and walk before trying to run.
India's RTA is due for program launch in September, but it also would compete with current aircraft at first, beginning with a 70-seat version planned to enter service in 2020. The first stretch version is set to have 90 seats and, again, would probably not appear until well into the 2020s, even if the 70-seater is delivered on time. Seven years is a generous schedule, but the Indian team has less experience than the Chinese in commercial aircraft and Indian aircraft programs tend to be late. The development budget is 43.55 billion rupees ($726 million).