NAL Saras Light Transport Aircraft(LTA),Indian Air Force
NAL Saras is an Indigenous twin-engine,multirole light transport aircraft being designed and developed jointly by Indian Companies National Aerospace Laboratories (NAL) and Hindustan Aeronautics limited (HAL) for the Indian Air Force.It is the first Indian multi-purpose civilian aircraft in the light transport aircraft category which is designed to execute passenger and freight transport,remote sensing,flight training,aerial surveillance,coastal surveillance,border patrolling and medical evacuation missions.
Two NAL Saras prototypes have been produced to date.It took its first flight on 29 may,2004.Third prototype is planned to be built.The unit cost to build these aircrafts is $21 Million.Second prototype crashed at the open space near Bidadi, situated 30km away from Bangalore, in March 2009 during flight tests. The crash killed two IAF test pilots and a flight engineer.
NAL received an order from the IAF to supply 15 Saras aircraft.deliveries will begin in 2014 and conclude in 2017.Currently The first prototype will be upgraded to meet the latest design criteria including higher-power 1,200 hp (895 kW) Pratt & Whitney Canada PT6A-67A engines and improvements to the flight control and flight operations systems. The upgraded PT1 is due to make its first flight by the end of 2011 leading to certification and first deliveries in 2013 and 2014 respectively
Design ,Airframe and Features
The Saras was designed to fly both day and night from semi-prepared airfields and grass runways even in hostile environments. It was designed to manoeuvre in hot temperatures and high altitudes. It was designed adhering to the FAR-25/23 standard regulations and can offer air taxi and commuter services.
The Aircraft will be 15.02m long ,5.20 m high with the wingspan of 14.70 m and has crew capacity of 3(pilot,Co-Pilot,Flight Engineer) with the additional capacity of carrying 14 passengers in its pressurised cabin.The aircraft will feature a conventional all metallic fuselage and carbon fibre composite (CFC) wings.The cabin is being build to flexibly suit commuter,executive with luxury seats,executive with deluxe seats,ambulance and combat versions.
Avionics and Cockpit
The SARAS will be incorporated with latest Arinc-429 simpatico digital avionics suite which includes CH-3100 attitude and heading reference system,TDR-94 transponder,VHF-422-B communication system,ADF-462 automatic direction finder,ALT-4000 radar altimeter,VOR-432 voice recorder and BME-442 distance measuring equipment.
It will also equipped with encompass air speed indicator,GPS receiver,inertial sensor unit, automatic flight control system, radio tuning unit, cockpit voice recorder and flight data acquisition unit. The glass cockpit in which two adjacent seat for pilot and co-pilot will be fitted will feature two Barco MFD 6.8/1 multifunctional displays,two primary flight displays with EFIS control panel,engine instrument display and colour weather radar display.There will be the great visibility from the all round glass canopy of cockpit to the flight crew.
Engine and Performance
The NAL SARAS will be powered by 2X Pratt & Whitney Canada PT6A-67A turboprop engines that are capable of producing 895 kw of thrust each.The transmission system includes epicyclic speed reduction gear box to minimise the propeller noise by optimising the output speed.The 2.65 m diameter propeller can make 1700 rpm in pusher configuration.
The aircraft fly with the maximum takeoff weight of 7100 kg with the maximum speed of 550 km/h and cruise speed of 520 km/h.The aircraft has maximum range of 920km with the maximum endurance will be 4 hours 45 minutes.It can climb at the rate of 10.5m/sec. The ferry range and service ceiling of the aircraft will be 1,935km and 7,500m respectively.
Modifications in First and Second Prototypes
While first aircraft was clearly overweight at 5,118kg compared to the 4,125kg design specifications.second prototype Saras aircraft lost 400kgs, but it was still heavy by 500kgs which were to be addressed on third Prototype. NAL has developed a third prototype, but it is yet to take its first flight due to weight issues.