Saras spreads its wings at Indian airshow
On display at Aero India 2005 earlier this year (see facing page) was the Saras, a low-wing aircraft with an mtow of 13,450 pounds and powered by two 850-shp Pratt & Whitney Canada PT6A-66 turboprops driving Hartzell five-blade pusher propellers, being developed by India’s National
Aerospace Laboratories (NAL). The first development prototype has been flying since last August, and by the time of Aero India 2005 it had amassed a dozen test sorties totaling seven hours. The Saras flew several times at the show. National type certification is expected in 2007.
The launch customer is the Indian air force, which has ordered six aircraft for liaison, small freight and passenger carriage, air ambulance and crew training. Although India’s military is the launch customer for the airplane, it is designed primarily for the civil market, to operate from hot-and-high airfields and as a VIP transport. Earlier this year, at its site in Bangalore, NAL began assembly of a second prototype, having received airframe parts and systems from Indian and foreign subcontractors.
The Saras was designed for feeder and air-taxi operations from rough or semi-prepared strips. The basic version is a 14-seat transport with a pressurized cabin that permits cruising at 25,000 to 30,000 feet. Cruise speed ranges between 300 and 340 knots, according to NAL, and the airplane has a range of up to 1,130 nm.
The gently swept wing of the airplane has an aspect ratio of 8.5 and a rather
high 15-percent thickness. It uses what NAL describes as a “first-generation passive laminar-flow aerofoil.” High-lift devices are limited to single-slotted trailing-edge flaps, but these are sufficient to keep takeoff and landing runs within 2,300 feet. The all-metal construction of the Saras is designed for low-cost streamline manufacture, and composites are used only in aerodynamic control surfaces and fairings.
Certification requires construction of three airframes, including one for ground tests. FAA certification to FAR Part 25 is targeted after the Saras proves a mature product in domestic service. The Saras project endured several ups and downs until the Indian government finally gave its go-ahead in 1999. This followed a years-long dormant period after completion, in the early 1990s, of definition studies undertaken jointly by NAL and Russia’s Myasishchev. Having chosen the main aerodynamic features of the new aircraft, the partners separated, with NAL pursuing the 14-seat Saras and Myasishchev the 18-seat M-102 Duet, differing in fuselage length.
The Saras’ avionics are primarily Indian and French, but St. Petersburg-based NIIRS hopes that its newest Kontur weather radar will be selected to equip the aircraft.
It will complement the Saras’ avionics suite, which includes 6- by 8-inch LCDs and GPS navigation.