TYPE: Aerobatic two-seat biplane.

PROGRAMME: Original German design first flew 27 April 1934; civil certification 3 October 1938; name refers to naval cadet; in addition to some 3,000 by parent firm (ending March 1941), licensed manufacture undertaken in Japan (339 K9W floatplanes and 1,037 Ki-86As), Spain (555 CASA 1.131s), Czechoslovakia (10 Tatra 131s and 300 Bu 131s, plus 260 Aero C.104s after 1945) and Switzerland (130 by Dornier). Last of some 5,700 were those produced in Spain, 1960.
SSH T-131 launched in March 1990, based on engineering drawings of Czech Bu 131D version (T and P in designations indicate Tatra and Poland). First of four pre-series aircraft flew 8 July 1994; first production aircraft exported to Austria in kit form December 1994 and made maiden flight 7 June 1997.

CURRENT VERSIONS: T-131P: Early version, with 78.3 kW (105 hp) Walter Minor 4-III four-cylinder inverted in-line engine and Hoffmann HO-40AHM-180 two-blade fixed-pitch metal propeller. Production complete.
T-131PA: More powerful version, with 103 kW (138 hp) LOM M 332AK four-cylinder, in-line engine. Prototype (SP-FPY) first flew 9 August 1995. Current baseline version; Polish certification under way in 2001 (latest information received), as step towards main objective of full standard certification in Germany.
Description applies to T-131PA.

CUSTOMERS: Three (including prototype) T-131Ps built 1994-95, of which two exported to Sweden. Total of 15 T-131PAs registered by early 2002, including two in Austria; at least seven to German owners, but retaining Polish registrations, and one each to Poland and Switzerland.

COSTS: Development Zł 15 million (2000); standard T-131PA €100,000 (2001).

DESIGN FEATURES: Single-bay biplane with interchangeable upper and lower wings, braced by pair of I-struts each side. This version based on Bü 131D, with ball bearings in control pivots and tailwheel, although Hirth 504A-2 engine replaced.
Wings have Göttingen aerofoil section (thickness/chord ratio 10.5 per cent) and 11° leading-edge sweepback; dihedral 3° 30' (upper), 1° 30' (lower); incidence -1° 30'; twist -1° 30'.

FLYING CONTROLS: Conventional and manual. Mass-balanced ailerons on all four wings; non-balanced rudder; trim tab in each elevator. No flaps.

STRUCTURE: Welded 4130 chromoly steel tube fuselage and tail unit; wooden wing spars (two) and ribs. Mostly Ceconite fabric covering except for metal engine cowling and around cockpit area. Fuel tank of glass fibre and carbon fibre.

LANDING GEAR: Non-retractable, with sprung 200x50 tailwheel; mainwheels 420x150 on forward-raked legs. Tyre pressures: main 1.50 bar (53 lb/sq in), tail 2.50 bar (88 lb/sq in). Hydraulic brakes.

POWER PLANT: One 104 kW (140 hp) LOM M 332AK four-cylinder in-line engine, driving an MT32.110/12 two-blade fixed-pitch wooden propeller. Fuselage fuel tank, capacity 85 litres (22.5 US gallons; 18.7 Imp gallons), of which 80 litres (21.1 US gallons; 17.6 Imp gallons) are usable. Oil capacity 8.5 litres (2.25 US gallons; 1.9 Imp gallons).

ACCOMMODATION: Two persons in tandem, open cockpits.

SYSTEMS: 24 V DC electrical system (generator and two batteries).

AVIONICS: Basic VFR standard; other avionics to customer's requirements.