Designed by Pavel Tsybin to a 1944 specification, the Ts-25 was of a high-wing design, with a box-shaped fuselage featuring a hinged nose for ease of loading the aircraft’s cargo. The aircraft had a fixed tricycle landing gear, with skids to aid in landing, and was of steel-tube-braced wooden construction with the nose covered in fabric. The fuselage was otherwise covered in plywood; the wing was tapered, with its spar being steel-tube strut braced. The intended load of the aircraft consisted of a jeep-type vehicle and a 57 mm (2.2 in) anti-tank gun.

Following flight tests that completed in 1948, the Ts-25 was accepted for production;[1] it is regarded as the first domestically produced glider to be built in significant quantities for the Soviet Airborne Forces (VDV). It was first publicly displayed at the 1948 Tushino Air Display. Eventually up to 480 of the aircraft were built at the Chkalovsk manufacturing plant between 1948 and 1954. Some were used by the VDV in training maneuvers. One was modified with 25 passenger seats for evaluation for potential civilian use on routes including Moscow, Gorki, and Novosibirsk. Two were supplied to the Czechoslovak Air Force in 1952 and given the desigation NK-25; the Yakovlev Yak-14 was preferred by the Czechs.

In 1950 two Ts-25s, towed by Ilyushin Il-12 transports, were used to resupply Polar Station SP-2.

Variants

Ts-25
Main production version, 480 built.

Ts-25M
Powered version; one built. Powered by two Shvetsov M-11FR-1 radial engines each producing 165 hp (123 kW).

NK-25
Czech designation for Ts-25.

Wingspan: 24.38 m (79 ft 11.875 in)
Length: 16.15 m (52 ft 11.8 in)
Height: 5 m (16 ft 5 in)
Wing area: 75.0 m2 (807 sq ft)
Empty weight: 1,787 kg (3,940 lb)
Max takeoff weight: 4,200 kg (9,259 lb)
Maximum speed: 230 km/h (140 mph, 120 kn) in tow
Landing speed: 90 km/h (56 mph; 49 kn)
Crew: two pilots
Capacity: 25 troops or 2,500 kg (5,500 lb) cargo

Designed by Kempes Trager and John Bierens, the T-3, which first flew in 1951, uses a set of Laister-Kauffmann LK-10A wings with a new all-metal fuselage with V-tail and retractable wheel. Later the wing was rebuilt and a new all-metal tail was incorporated.

Wing span: 15.24 m / 50 ft
Wing area: 13 sq.m / 140 sq.ft
Aspect ratio: 17
Airfoil: NACA 4418
Empty Weight: 227 kg / 500 lb
Payload: 113 kg / 250 lb
Gross Weight: 340 kg / 750 lb
Wing Load: 26.15 kg/sq.m / 5.1 lb/sq.ft
MinSink: 0.67 m/s / 2.2 fps / 1.30 kt
L/DMax: 28 77 kph / 42 kt / 48 mph
Seats: 1
No. Built: 1
Structure: wood/ fabric wings. Metal fuselage and tail.

This Standard Class single-seater was designed by John Sellers, who was also responsible for the Slingsby T53, for Torva Sailplanes Ltd of Scarborough, Yorkshire, which company he had formed in September 1969 with Chris Riddell, and it was intended to be a moderately priced type with good performance suitable both for clubs and the private owner and competition pilot, for whom two production versions were to have been marketed.

These were the Torva 15 Standard for club use and the Torva 15 Sport for the private owner and contest flying, the latter being fitted with flaps and having a retractable monowheel, while the Standard had provision for up to 130lb of water ballast. The Torva 15 was noteworthy as being the first British designed sailplane to be constructed largely of glass-reinforced plastics (GRP), although the wings have plywood ribs and the fuselage has plywood and foam sandwich frames to support its GRP shell and side longerons. Design work began on 6 October 1969 and construction of the Torva 15 Sport prototype (also known as the Torva TA 1) commenced on 16 March 1970; this first flew on 8 May 1971 in the hands of Chris Riddell. A modified Wortmann aerofoil section was chosen for the cantilever shoulder wings to give a very high lift coefficent for achieving a good rate of climb in weak British thermals, and also to give a low stalling speed for short-field landings. The wings have a GRP spar with ply webs and GRP/balsa shell; both the ailerons and flaps are of GRP with a foam core, the ailerons having variable differential and drooping with the flaps, but being isolated from the latter at the flap full-down position. Light alloy Schempp-Hirth air brakes are also fitted. The fuselage and canopy shape were computer calculated to achieve a good aerodynamic shape and roomy cockpit; the pilot sits under a Suntex lift-off transparent one-piece canopy and has a GQ five-point seat harness. The tail surfaces have GRP/balsa shells and plywood webs, the tailplane being an all-moving surface with a geared anti-balance tab. The retractable rubber-sprung monowheel is located forward of the eg and is manually retracted, with an internal expanding brake; there is also a GRP sprung tailskid with a small wheel.

Only three more Torva 15s were built after the prototype, as the company was forced to close down; these were also known as TA 2 Sprites.

Torva 15 Standard
Span: 15.0 m / 49 ft 2.5 in
Length: 7.11 m / 23 ft 3.25 in
Height: 5 ft 0 in
Wing area: 11.3 sq,m / 121.5 sq.ft
Aspect ratio: 20.0
Empty weight: 238 kg / 525 lb
Max weight: 408 kg / 900 lb
Water ballast: 59 kg / 130 lb
Max speed: 134 mph / 116 kt / 216 km/h (in smooth air)
Max rough air speed: 80 kt / 148 km/h
Stall speed: 35 kt / 65 km/h
Min sinking speed: 0.62 m/sec / 2.03 ft/sec at 50 mph / 43.5 kt / 81 km/h
Best glide ratio: 37:1 at 51 mph / 44 kt / 82 km/h