English name: Crane
TYPE: Twin-turboprop transport.
PROGRAMME: Originated as six/nine-passenger light transport shown in model form at Moscow Aerospace '90 exhibition; revised design announced by Myasishchev 1993, with name Delphin; India had comparable project; general agreement concluded 1993 to combine Myasishchev and Indian programmes, Russian version being known as M-102 Duet and Indian version as Saras (species of Indian crane). Full-scale mockup shown at 1993 and 1995 Moscow Air Shows. Prototype construction (two in Russia, one in India originally) planned to begin in September 1994, but Indian share of private venture capital not secured until early 1996. Detailed engineering began in April 1996 following finalisation of design late in previous year; however, in 1997 Myasishchev was proceeding with unilateral development of the similar M-202, yet by 2001, was again promoting M-102 version; neither has progressed to the prototype stage in Russia. In early November 2001, Russia and India signed a protocol on construction of the M-102/Saras.
India elected to continue with the Saras as a national programme, although some collaboration with the former Russian partner was not ruled out. Government secured private backing of Taneja Aerospace and Kumaran Industries, plus financial support from the Indian Technology Development Board Hindustan Aeronautics Ltd also became a major partner in the development programme and to build production aircraft at Nasik. Release of further government funding in mid-1999 enabled work to begin on manufacture (by HAL) of two flying prototypes and a structural test airframe. First prototype (VT-XSD) reported in February 2001 to be 80 per cent complete, with first flight then expected by end of 2001, but in following month, programme management board called for "rigorous weight control exercise". Roll-out 4 February 2003; first flight was expected in June 2003. Registration Vt-XRM reserved for second prototype. Certification, expected by June 2005, will be FAR Pt25.
CUSTOMERS: At least 250 Indian orders forecast over 15 years. Indian Air Force has initial requirement for six, to replace Dornier Do 228s, by 2005; Indian coast guard also consideration Saras as Do 228 replacement.
COSTS: Design and development cost quoted in February 1996 as US$40 million. Late in 1996, cost re-estimated as US$60 million, including flight test phase. Indian government approved Rs1.3 billion (US$30 million) in June 1999 to enable prototype manufacture to begin. Estimated unit price US$3.75 million (2001).
DESIGN FEATURES: Suitable for operations in hot-and-high conditions (typically, airfield at 2,000 m; 6,560 ft at up to 45oC), and from semi-prepared runways. Unconventional twin pusher propeller configuration. High aspect ratio, low-mounted wings, with straight taper; pressurised circular-section fuselage; T tailplane on sweptback fin; engines pylon-mounted each side of rear fuselage.
Wing section GA(W)-2 (modified); leading-edge sweep 5o; thickness/chord ratio 15 per cent; 4o dihedral; 2o incidence; 2o twist.
FLYING CONTROLS: Conventional and manual. Tabs in all control surfaces; electrically operated pitch, roll and yaw trim; yaw damper; spoilers and 25 per cent chord, single-slotted Fowler flaps; dual-channel three-axis autopilot. Highly swept ventral fins provide nose-down pitching moment at high AoA.
STRUCTURE: Mixed construction of aluminium alloy (fuselage, engine pylons and fixed portion of wing) and composites (nosecone, wing/body fairing, wing moving surfaces and tips); designed for 30,000 hour life; fail-safe philosophy for all primary structures and major attachments; incorporates damage tolerance features. Two-spar wing with integrally milled skin riveted to stringers; two-spar flaps with honeycomb sandwich filler; single-spar ailerons with honeycomb filler; single-piece, two-spar metal tailplane and three-spar metal fin.
LANDING GEAR: Hydraulically retractable tricycle type, with single mainwheels and single steerable (±53o) nose unit. Mainwheels retract inward into wingroot fairings, nosewheel forward. Oleo-pneumatic shock-absorbers. Mainwheels 26x8.75, pressure 5.52 bar (80 lb/sq in); nosewheel 17.5x6.3, pressure 3.79 bar (55 lb/sq in); air-cooled carbon brakes. Minimum turning radius 8.10 m (26 ft 7 in) at nosewheel.
POWER PLANT: Two 634 kW (850 shp) Pratt & Whitney Canada PT6A-66 turboprops, pylon-mounted on sides of rear fuselage; Hartzell five-blade, constant-speed pusher propellers, rotating in opposite directions. Integral fuel tank in each wing, combined capacity 1,608 litres (425 US gallons; 354 Imp gallons), of which 1,595 litres (421 US gallons; 351 Imp gallons) are usable. Gravity refuelling point in port wing upper surface; optional single-point pressure refuelling point at starboard wingroot.
ACCOMMODATION: Two-person flight deck with dual controls, but to be certified also for one-pilot operation. Alternative layouts for 14 economy class passengers in single seats at 76 cm (30 in) pitch, with centre aisle, rear lavatory and total of 1.1 m3 (39 cu ft) for baggage in forward and rear compartments; or 18 passengers in commuter layout. Typical executive interior could have eight seats, tables, wardrobe, baggage compartment, galley and lavatory. Ambulance version capable of carrying six stretchers, with seats for two medical attendants, medical supplies storage, baggage compartment and lavatory. Various passenger/cargo arrangements or special mission interiors optional in combi version. Door at front on port side, hinged downward, with integral airstairs; overwing Type III emergency exit on each side. Baggage compartment door on port side tailcone.
SYSTEMS: Bootstrap environmental control system and pneumatic cabin pressure control system; cabin pressure differential 0.45 bar (6.5 lb/sq in). Hydraulic system (pressure 207 bar; 3.000 lb/sq in) for landing gear actuation, brakes and nosewheel steering; 4 litres (1.06 US gallons; 1.27 Imp gallons)/min electrically powered hydraulic pump; pneumatic system for emergency lowering of landing gear.
Primary electrical power is 28 V DC, supplied by two 12 kW starter/generators; 43 Ah Ni/Cd battery provides emergency power for essential loads for approximately 30 minutes, including three engine restarts. Two solid-state inverters supply 115/26/5 V AC power at 400 Hz for instrumentation; AC power for anti-icing and windscreen heating obtained via alternators. Emergency oxygen system for crew and passengers (two 1,400 litre; 49.4 cu ft bottles), plus two 122 litre (4.3 cu ft) portable bottles and masks for first aid. Engine fire and cabin smoke detection systems. Halon fire extinguishing. De-icing boots on wing leading-edge nacelle intakes.
AVIONICS: Integrated digital system (ARINC 429 compatible).
Comms: VHF (two), optional HF, intercom/PA system, TCAS II transponder and CVR.
Radar: Weather radar.
Flight: Autopilot (dual-channel, three-axis), ADF, VOR/ILS, maker beacon receiver, DME, radar altimeter, air data sensor and computer, AHRS, flight control computer and flight director standard; GPS, satcom, Selcal and flight management system optional.
Instrumentation: Four-tube EFIS; 'return home' standby instrumentation.