Civil Aviation Department of India TG-1 / ATS-1 Ardhra
Hindustan Aeronautics ATS-1 Ardhra
This tandem two-seater advanced training sailplane was designed by the Technical Centre of India's Civil Aviation Department at New Delhi; it was formerly designated TG-1.
Of conventional wooden construction with fabric covering the ATS-1 resembles its predecessor, the single-seat HS-II Mrigasheer, although the cantilever shoulder wings have 3° of forward sweep and are plywood-covered multi-spar structures with fabric covered trailing edges. The plywood plain ailerons are also fabric covered; no flaps are fitted but there are wooden air brakes in the upper and lower wing surfaces. The tail unit is of similar construction to the wings, with a trim tab in the starboard elevator. The fuselage is a semi-monocoque wooden structure and there is a non-retractable rubber-sprung monowheel with an expanding shoe brake, plus a rubber-sprung skid under the nose and a tail skid.
The two pilots sit in tandem under a long one-piece blown flush-fitting canopy.
The prototype, VT-GEJ, first flew on 5 March 1979 and was certificated by the Indian DGCA in November that year. Plans for large scale production were underway early in 1980 for the National Cadet Corps and civil clubs. The second prototype which was then under construction has 2° geometric twist (washout) from 50% span to the wing tips, and the dihedral increased to 3°.
The Indian Air Force ordered fifty examples in the early 1980s to be produced by Hindustan Aeronautics and the type was approved for use for flying by cadets.
Length: 8.61 m (28 ft 3 in)
Wingspan: 16.50 m (54 ft 2 in)
Airfoil – Root: FX 61-184
Airfoil – tip: FX 61-184
Height: 2.46 m (8 ft 1 in)
Wing area: 21.8 m2 (235 ft2)
Aspect ratio: 12.5
Empty weight: 328 kg (723 lb)
Gross weight: 508 kg (1,120 lb)
Maximum speed: 210 km/h (130 mph)
Max aero-tow speed: 77.5mph
Min sinking speed: 2.56 ft/sec
Best glide ratio: 28:1 a 54 mph
Rate of sink: 0.8 m/s (160 ft/min)
Crew: Two, pilot and instructor