Saras Light Transport Aircraft (LTA)
Named Saras, after the Indian crane known for its grace and beauty in flight, the Light Transport Aircraft (LTA) has the design objective of being able to carry between eight and 14 passengers and extendable to an 18-passenger variant, in multiple modes of operation.
The flight-testing expertise and resources in India have matured adequately to undertake prototype flight-testing. The Light Transport Aircraft (LTA) program, SARAS a turboprop aircraft being developed indigenously by National Aerospace Laboratories (NAL) of Government of India, is the first civil aircraft program aimed at certification standard, FAR 25. The program is unique in that the propeller configuration of SARAS is pusher type and it is the first indigenously designed civil transport aircraft in India. In light of its unique configuration and in absence of any precedence for certification of an indigenously designed and developed aircraft against a FAR airworthiness standard in India, the prototype flight-testing of SARAS aircraft becomes critical.
The SARAS programme is a NAL initiative to create a vibrant Indian civil aviation industry. The programme was the outcome of a series of studies in the late 1980's which pointed to the requirement of a fourth level ("feeder) airline for India.
SARAS is a twin turbo-prop multi-role aircraft with air taxi and commuter services as its primary roles. SARAS will have a seating capacity of up to 14 passengers in the high density version. With a large and pressurised cabin, the aircraft will have a level of comfort comparable to regional aircraft. SARAS will be well-suited to fulfil a variety of other roles such as executive transport, light package carrier, remote sensing and aerial research service, coast guard, border patrol, air ambulance and other community services.
SARAS is powered by two Pratt and Whitney Canada PT6A-66 engines driving 2.16m diameter 5 bladed propellers at 2000 rpm in a pusher configuration. The engines are mounted on stub wings locate at aft fuselage resulting in quieter cabin and undisturbed flow on the wing.
Attention has been given right from the beginning for easy maintenance and thus to increase aircraft availability. Equipment needing inspection / maintenance are provided easy access. The PT6A-66 engine is of modular construction and thus easy to maintain. Furthermore, the cowling is designed in such a way that the front and rear ends are removable and centre section has swinging doors and panels to have full access to servicing points on engine and aircraft accessories. Hot section inspection which is usually carried at mid time between overhauls can be done in-situ by removing rear end of nacelle. The avionics equipment, hydraulic system and the air conditioning system bays, all have large doors for easy access.
In mid 1980s, Research Council recommended that NAL should study the civil aviation requirements of India and recommended ways and means of establishing a viable civil aviation industry. It further recommended that NAL should carryout a formal techno economical feasibility study of a multi role Light Transport Aircraft (LTA - renamed SARAS in October 1993). The feasibility study (November 1989) showed that there was a significant demand for a 9-14 seat multi-role LTA in the country and estimated a market potential of about 250-350 aircraft in the next 10 years. NAL submitted the feasibility study report to RC in November 1990 and started its search for an industrial partner. Though two organisations expressed their interest to be the industrial partners, none of these risk-sharing partnerships materialised, as these organisations backed out. In August 1995, RC recommended to put up the proposal to the competent financial authority (CFA) after identifying the industrial partner and the project cost was estimated at Rs.126 crore. The first test flight of multirole light transport aircraft 'Saras' was scheduled for December 2002. The project of 'Saras' was sanctioned on September, 24 1999 with initial schedule of its maiden flight by March 2001. The delay was attributed to technology embargoes and technological complexities. As against the target of January 2001, the Prototype-I flew in May 2004, i.e. after a delay of more than three years. Prototype-II undertook its first flight in April 2007, after a delay of more than five years. Due to the above time overrun, the cost of the project increased by Rs.22.53 crore i.e. a cost escalation of almost 17 percent.
The flight-testing expertise and resources in India have matured adequately to undertake prototype flight-testing. The Light Transport Aircraft (LTA) program, SARAS a turboprop aircraft being developed indigenously by National Aerospace Laboratories (NAL) of Government of India, is the first civil aircraft program aimed at certification standard, FAR 25 . The program is unique in that the propeller configuration of SARAS is pusher type and it is the first indigenously designed civil transport aircraft in India. In light of its unique configuration and in absence of any precedence for certification of an indigenously designed and developed aircraft against a FAR airworthiness standard in India, the prototype flight-testing of SARAS aircraft becomes critical. The first flight of SARAS aircraft was flown on 29 May 2004 and the prototype flight-testing was progressing satisfactorily.
Development of SARAS suffered from delays and deficient project management. Even after a lapse of eight years and cost overrun of Rs.22.53 crore, NAL is awaiting certification of airworthiness for SARAS aircraft from Director General of Civil Aviation (DGCA) as NAL failed to bring down its weight within the permissible limit and is yet to carry out various tests and generate documentation. As of 2008, flight certification was expected only after 2010 and NAL may have to make a third prototype as well.
According to NAL estimates, there is a demand for such aircraft with the requirement going up from 30-40 aircraft initially to 200 aircraft over the next 10-15 years.