TYPE: Advanced jet trainer.

PROGRAMME: Kawasaki named prime contractor 4 September 1981 by Japan Defence Agency; T-4 based on Kawasaki KA-851 design, by engineering team led by Kohki Isozaki; basic design studies completed October 1982; funding approved in FY83 and FY84 for four flying prototypes; prototype construction began April 1984; first flight of first XT-4 (56-5601) 29 July 1985; all four delivered between December 1985 and July 1986, preceded by static and fatigue test aircraft.
Production began FY86; first flight of production T-4, 28 June 1988; deliveries started 20 September 1988 to begin replacement of Lockheed T-33A and Fuji T-1A/B. Production completed March 2003; Fuji and Mitsubishi each had 30 per cent share in programme.

CUSTOMERS: JASDF T-4s used for pilot training, liaison and other duties; total of 212 (including prototypes) ordered by September 2000, of which last was delivered in March 2003. Used by Nos. 31 and 32 Flying Training Squadrons of 1st Air Wing at Hamamatsu, near Tokyo; and in small numbers by instrument rating/communications flights of most combat squadrons and regional HQ flights. First delivery to Blue Impulse aerobatic team (11 Squadron/4th Wing) 1994; nine operational for air show season.

COSTS: Unit cost ¥2,251 million (2000).

DESIGN FEATURES: High subsonic manoeuvrability; ability to carry external loads under wings and fuselage; anhedral mid-mounted wings, with extended chord outer panels giving dog-tooth leading-edges; tandem stepped cockpits with dual controls; baggage compartment in centre-fuselage for liaison role.
Supercritical wing section; thickness/chord ratio 10.3 per cent at root, 7.3 per cent at tip, anhedral 7° from roots; incidence 0°; sweepback at quarter-chord 27° 30'.

FLYING CONTROLS: Hydraulically actuated controls; plain ailerons with Teijin powered actuators; all-moving tailplane and rudder use Mitsubishi servo actuators; double-slotted trailing-edge flaps; no tabs; airbrake on each side of rear fuselage.

STRUCTURE: Aluminium alloy wings, with slow crack growth characteristics; CFRP ailerons, fin, rudder and airbrakes; aluminium alloy flaps (with AFRP trailing-edges), tailplane (CFRP trailing-edge) and fuselage with slow crack growth characteristics; titanium used sparingly in critical areas. Kawasaki builds forward fuselage and is responsible for final assembly and flight testing; Fuji builds rear fuselage, wings and tail unit; Mitsubishi builds centre-fuselage and engine air intakes.

LANDING GEAR: Hydraulically retractable tricycle type, with Sumitomo oleo-pneumatic shock-absorber in each unit. Single-wheel main units retract forward and inward; steerable nosewheel retracts forward. Kayaba (Honeywell) mainwheels, tyre size 22x5.5-13.8, pressure 19.31 bar (280 lb/sq in); Kayaba (Honeywell) nosewheel, tyre size 18x4.4-11.6, pressure 12.76 bar (185 lb/sq in). Kayaba (Honeywell) carbon brakes and Sumitomo (Hydro-Aire) anti-skid units on mainwheels. Minimum ground turning radius 9.45 m (31 ft 0 in).

POWER PLANT: Two 16.37 kN (3,680 lb st) Ishikawajima-Harima F3-IHI-30 turbofans, mounted side by side in centre-fuselage. Internal fuel in two 401.25 litre (106 US gallon; 88.3 Imp gallon) wing tanks and two Japanese-built Goodyear rubber bag tanks in fuselage, one of 776 litres (205 US gallons; 170.7 Imp gallons) and one of 662.5 litres (175 US gallons; 145.7 Imp gallons). Total internal capacity 2,241 litres (592 US gallons; 493 Imp gallons). Single pressure refuelling point in outer wall of port engine air intake. Provision to carry one 454 litre (120 US gallon; 100 Imp gallon). ShinMaywa drop tank on each underwing pylon. Oil capacity 5 litres (1.3 US gallons; 1.1 Imp gallons).

ACCOMMODATION: Crew of two in tandem in pressurised and air conditioned cockpit with wraparound windscreen and one-piece sideways (to starboard) opening canopy. Dual controls standard; rear (instructor's) seat elevated 27 cm (10.6 in). UPCO (Stencel) SIIS-3 ejection seats and Teledyne McCormick Selph canopy severance system, licence-built by Daicel Chemical Industries. Baggage compartment in centre of fuselage, with external access via door on port side.

SYSTEMS: Shimadzu bootstrap-type air conditioning and pressurisation system (maximum differential 0.28 bar; 4.0 lb/sq in). Two independent hydraulic systems (one each for flight controls and utilities), each operating at 207 bar (3,000 lb/sq in) and each with separate air/fluid reservoir pressurised at 3.45 bar (50 lb/sq in). Flow rate of each hydraulic system 45 litres (12 US gallons; 10 Imp gallons)/min. No pneumatic system. Electrical system powered by two 9 kW Shinko engine-driven starter/generators. Tokyo Aircraft Instruments onboard oxygen generating system.

AVIONICS: Comms: Mitsubishi Electric J/ARC-54 VHF/UHF com, and Nagano JRC J/AIC-103 intercom.
Flight: Nippon Electric J/ARN-66 Tacan, Toshiba J/ARN-69 VOR/ILS, Toyo Communication (Teledyne Electronics) J/APX-106 SIF, Japan Aviation Electronics (Honeywell) J/ASN-3 laser gyro AHRS, Tokyo Keiki (Honeywell) J/ASK-1 air data computer, Tokyo Aircraft Instrument J/ASH-3 VGH recorder and Kanto (Smiths) J/ASH-4 FDR.
Instrumentation: Shimadzu (Kaiser) J/AVQ-1 HUD.

ARMAMENT: No built-in armament.

EQUIPMENT: Two Nippi pylons under each wing for carriage of drop tanks (see Power Plant) or travel pods; one Nippi pylon under fuselage, on which can be carried target towing equipment, ECM/chaff dispenser, travel pod or air sampling pod.