In the meantime, ATR has been pushing the -600 series aircraft - the successor variant of its ATR 42 and 72 models - while Bombardier has been marketing the latest upgrade to its turboprop family: the Q400 NextGen.
Gordon Pratt, director of QSeries programme management at Bombardier, says the manufacturer is still studying the Q400X - a stretched version of its 78-seat Q400 - but there is "no specific timeline" as to when the planned project will proceed.
In March 2009, Bombardier commercial aircraft president Gary Scott said the company was examining a 2013-14 timeframe to offer a stretched Q400. However, Bombardier has since tempered those comments and now says the 2013-14 timeframe "did not refer to a hard deadline, it was more about hopes and aspirations".
The Q400X, being designed for the 90-seat sector, could be brought to the market sooner than the similarly sized turboprop under consideration by European competitor ATR, notes Pratt. "The Q400X as a derivative would have the least development time because 90% of it is in operation today as the Q400," he says, adding that Bombardier "would like the market for the Q400X to be ready now. We are seeing momentum in that directionand [when conditions are right] we can launch the programme and get going relatively quickly."
ATR is as reluctant as Bombardier to put a timeframe on developing the 90-plus-seat turboprop it is evaluating. The EADS-Alenia joint venture has a technical and marketing team working on the project and is in discussions with airlines and engine manufacturers to assess demand and to see what kind of efficiency gains can be achieved.
Earlier this year, ATR revealed that it had entered advanced discussions with Pratt & Whitney and General Electric on powering a new, larger turboprop. In May, ATR head of marketing Mario Formica said at the Regional Airline Association convention in Milwaukee that the manufacturer would decide in 2011 whether to continue with its larger turboprop studies. He added that ATR "would like to enter the market at around 2016", were it to go ahead with the project.
Carbonfibre could play an increased role in any new turboprop design developed by ATR, but the airframer's technical director, Carmine Orsi, told Flight International in July that advanced aluminium alloy was the preferred material for the fuselage. ATR partner Alenia Aeronautica is free to use the carbonfibre construction and production technology it uses to build Boeing 787 fuselage barrels.
However, Orsi says that turboprop customers' preferred solution will remain the metallic skin and frame structure as the fuselage's proximity to the ground leaves it vulnerable to damage from loading equipment.
While it decides whether to proceed with plans for a larger turboprop, ATR has been working towards certification of its -600 series, the successor to the ATR 42-500 and 72-500 series. It includes such improvements as higher-thrust Pratt & Whitney Canada PW127M engines, increased payload, an enhanced cabin and an all-new Thales flightdeck.
The -600 cabin is constructed largely from polycarbonate, which ATR says offers increased knee clearance. Improved under-seat storage capacity and the redesigned overhead bins increase the total carry-on luggage capacity by 30%. The cabin on the -600 offers a 200kg (440lb) weight reduction over the -500 series interior, and can be retrofitted to the -500 because the two models retain the same interface with the cabin structure.
As of September, the ATR 72-600 had carried out two-thirds of its 150h test programme while the ATR 42-600 had carried out 30h of its 75h test programme. ATR is targeting the second quarter of 2011 for first delivery, and it is understood that certification could be achieved by the end of this year. The first -600 model will be delivered to Royal Air Maroc, which in March 2009 ordered two ATR 42-600s and four ATR 72-600s.
During the Farnborough air show in July, Brazilian carrier Azul signed a deal for 20 ATR 72-600s with options on a further 20, while Steven Udvar-Hazy's Air Lease venture ordered 10 of the type. This was followed in September by an order from Caribbean Airlines for nine 72-600s.
ATR chief executive Filippo Bagnato said earlier this year that the manufacturer would keep the 70-seat ATR 72-500 in its portfolio for the coming years because customers remain interested in the older version. He said there was no distinct point in the near future when ATR would cease offering the 72-500.
ATR in September delivered its 900th aircraft and said it expects to break the 1,000 barrier within two years. Brazil's Trip Linhas Aereas, ATR's second-largest customer, took delivery of the 900th aircraft at a ceremony in Toulouse.
Speaking to Flight International at the time, Bagnato said ATR would hold 2011 and 2012 output at the 50-plus aircraft it expects to deliver this year, but could increase this to 60 aircraft in 2013. Last year, ATR delivered 54 aircraft, one less than the previous year. As of 30 June, ATR had delivered 26 aircraft and secured 42 orders. Its backlog stood at 152.
As Bombardier waits for the right conditions to launch the Q400X, it is keenly promoting the Q400 NextGen - a new, upgraded version of the Q400, which Pratt says has been "very well-received" by the market. The upgraded turboprop features LED lighting, new ceiling panels, dished window sidewalls to allow more light to enter the window and larger overhead luggage bins.
Norwegian regional carrier Widerøe took delivery of the first Q400 NextGen in May 2009, following a decision by its parent company SAS Group to eliminate the standard Q400 from its fleet after a succession of landing-gear incidents. Pratt says Bombardier has addressed the landing-gear situation "to the satisfaction of our airline customers", and sales have been unaffected.
"Sales have not suffered. SAS continues to purchase Q400s so we've retained the customer and their commitment to the type," he notes. "When you look to the future market, it will be about more - more passengers to more destinations, more environmental performance and social responsibility, more passenger comfort and service. These are features the Q400 succeeds in delivering."
For this year, as of 31 July, Bombardier had taken orders for 22 QSeries aircraft and delivered 24. Its backlog stood at 73.
Both ATR and Bombardier are optimistic about the future market for turboprop aircraft. The Franco-Italian manufacturer has improved its market outlook and now expects to see a total market for 150 regional aircraft a year over the next 20 years. It anticipates that turboprops will represent 40% of this market.
In Bombardier's latest market forecast, of the 12,800 20- to 149-seat aircraft to be delivered between 2010 and 2029, 2,400 will be turboprops. Of these 2,400 aircraft, 100 will be in the 20- to 59-seat range, while the remaining 2,300 aircraft will have between 60 and 99 seats.
"Turboprops have remained fairly constant in terms of sales," says Bombardier's Pratt. "They've done well in the economic downturn." He sees an opportunity for the Q400 to step in and replace regional jets, particularly in the US market. "As the North American market grows back to health, airlines will turn to turboprops as fuel costs rise," he predicts.