India has decided to go with a turboprop design for its first indigenous regional aircraft and has released some preliminary specifications.
National Aerospace Laboratories is looking for foreign partners for the Regional Transport Aircraft RTA-70 and hopes to secure additional government funding later this year.
NAL officials say that they plan to design the RTA-70 with the Indian market in mind, adding that existing turboprops do not meet those requirements. These include higher fuel efficiency, short landing and take-off capability, and the ability to transport cargo.
This will give the aircraft 25% lower acquisition costs, 25% lower operating costs and 50% lower maintenance costs than existing turboprop regional aircraft, says NAL.
"Many towns and cities remain unconnected due to the cost of operations. Short take-off and landing abilities, capability to land on ill-equipped airfields, including all weather operations, can be of very high benefit," NAL says in its brochure for the RTA-70.
"Given the high cost of fuel and its implication to operating economics, developing an aircraft that is fuel-efficient compared to present regional aircraft can be very promising. Lower weight, lower drag can mean higher performance and lower emissions. Capability to carry cargo means additional revenue to an operator."
The 70-seat aircraft will have a range of 1,100nm (2,000km), and require a take-off field length and landing field length of 900m (2,950ft). The aircraft would have a length of 28.6m and a wing-span of 29.4m. The aircraft would have a service ceiling of 30,000ft, a cruising speed of 300kt, and the noise level would meet Stage 4 criteria.
The cabin, which would be able to seat four abreast, would have a length of 3.01m and height of 3.35m. The cargo hold would have a volume of 25m³ (880ft³).
NAL is eyeing a composite airframe. The aircraft will be powered by two "next generation turboprop engines", it adds. It would have a fly-by-wire control system, open distributed modular avionics, ADS-B navigation capabilities, and advanced displays.
The aircraft will have better "energy efficiencies" than its current rivals, says NAL. "It is now known that present regional aircraft have had lower energy efficiency than larger aircraft as they did not get full benefit of new technologies," it states. "There is an opportunity for developing new technolgies that will ensure that the salient features of the RTA can be met."
NAL officials were unable to say when they hope to move into the detailed design phase and begin the production of the aircraft.
Hindustan Aeronautics, the state-owned aerospace firm, will manufacture the aircraft. This agreement will be similar to a deal to produce the Saras transport aircraft, which NAL has developed primarily for the military, and the Tejas light combat aircraft from the Aeronautical Development Agency.
While NAL will be responsible for the RTA-70 development, it is seeking international partners to help it in several areas. Diehl has come on board to help design the cabin and the two teams unveiled a proposed cabin at India Aviation 2010 in Hyderabad.
"Initial seed funding has enabled preliminiary studies preliminary studies to commence," says NAL. This has been used for work on aerodynamics including computational fluid dynamics and wind tunnel studies, it adds, while preliminary studies on sizing, specifications and performance are in progress.