NAMC JL-8

TYPE: Basic jet trainer/light attack jet

COUNTRY OF ORIGIN: China

Export designation: K-8

PROGRAMME: Launched publicly (as L-8) at 1987 Paris Air Show as proposed export aircraft to be developed jointly with international partner. Subsequently proposed to be co-developed with Pakistan as partner (25 per cent share); aircraft then redesignated K-8 and named after mountain range forming part of China/Pakistan border. Pakistan decided 1994 against own assembly line, but agreed to reconsider if subcontracting share (12 per cent initially, but being increased to 25 per cent in mid-2001 by addition of front fuselage) should later increase to 45 per cent.

Manufacture of four prototypes started January 1989; three flying prototypes: 001 (first flight 21 November 1990), 003 (first flight 18 October 1991) and 004; 002 is static and fatigue test aircraft.
First preproduction aircraft (1001/L8 320101) used as demonstrator. Preproduction batch of six for Pakistan Air Force evaluation (ordered 9 April 1994) handed over in China on 21 September 1994 and delivered to PAF on 10 November that year; PAF evaluation (approximately 1,200 hours) completed in August 1995 aircraft reported subsequently in use from Air Academy, Risalpur China importing Progress AI-25 turbofans for use in domestic version, apparently now designated JL-8. One aircraft in use from 1997 by China Flight Test Establishment as variable stability testbed (K-8VSA) with fly-by-wire flight control system.

CURRENT VERSIONS: K-8: Initial version with TFE731 engine; as described.
K-8E: TFE731 -powered version for Egyptian Air Force, 80 of which ordered under contract signed on 27 December 1999. First 10 Chinese-built; Arab Organisation for Industrialisation (AOI) then assembling batches of 15 and 10 from CKD kits of medium-sized and smaller components respectively before progressing to 90 per cent local manufacture of final 45; first kit-assembled K-8E completed mid-2001 and some 35 achieved by end of 2002. Total of 33 items newly selected, developed or upgraded for this version include instrument panels and consoles; com/nav systems; fire-control system; fuel system; environmental control system; hydraulic system; and landing gear. K-8E flown for first time on 5 July 2000.
JL-8: Reported designation of Chinese domestic version when fitted with AI-25 engine.
K-8VSA: In flight variable stability testbed (serial number 320203), in use from 1997 by China Flight Test Establishment (CFTE). Equipped with digital fly-by-wire AFCS, sidestick controller and data acquisition system.

CUSTOMERS: Total of 12 preproduction K-8s (six each to PLA Air Force and Pakistan Air Force) delivered by end of 1996. Original joint venture agreement reportedly involved up to 75 for Pakistan Air Force, but Pakistan Secretary for Defence Production quoted in early 1996 as saying up to 100 needed eventually to replace Cessna T-37; however, SLEP for T-37 has postponed main K-8 requirement to about 2005. Chinese PLAAF originally had requirement for several hundred, of which 25 to 30 delivered by late 1999; of these, 20 reportedly equip No. 4 Flying Training School at Shijiazhuang; PLAAF now widely reported to have abandoned plans for full adoption. Myanmar Air Force last three of 12 delivered in September 1999. Zambian Air Force eight, and Namibian Air Force first four, also delivered in 1999. Three of Sri Lanka six (No. 14 Squadron) destroyed in Tamil Tiger attack on Katunayake AB, 24 July 2001. Egyptian Air Force had received about 45 (of 80) of K-8E version by late 2002, to replace Aero L-29. Venezuela considering purchase of 24 in late 2001. Interest also reported from Bangladesh, Cambodia, Eritrea, Laos and Thailand.

COSTS: US$3 million to US$3.5 million flyaway (1996) with TFE731 and Western avionics. Egyptian Air Force (80 aircraft) contract quoted as US$345 million (1999).

DESIGN FEATURES: Intended for full basic flying training plus parts of primary and advanced syllabi, but capable also of light ground attack missions. Sweptback vertical/non-swept horizontal tail surfaces.
Tapered low wings, with NACA 64A-114 (mod) root and NACA 64A-412 tip sections; sweepback 2° 13' 8" at quarter-chord, 1° 30' incidence at root, 3° dihedral from roots: -2° twist.

FLYING CONTROLS: Conventional and power-assisted; ailerons have hydraulic boost and artificial feel; variable incidence tailplane; electrically operated trim tab in rudder and port elevator. Aileron travel ±18°, elevators 16° up/28° down, rudder ±28°. Two-position Fowler flaps (23° for T-O, 35° for landing), and split airbrake under fuselage just aft of mainwheel doors, are hydraulically actuated.

STRUCTURE: All-metal damage-tolerant main structure; ailerons of honeycomb fin and rudder of composites. PAC share (initially only tailplane and elevators) increased to include fin, rudder, rear fuselage and engine cowling/access panels. First Pakistan-built subassemblies delivered to China in mid-1997; planned output by PAC of 12 tail units and three front fuselages in 2001; 24 and 12 respectively in 2002; 36 tails and undecided number of front fuselages in 2003.

LANDING GEAR: Hydraulically retractable tricycle type, with single wheel and oleo-pneumatic shock-absorber on each unit. Main units retract inward into underside of fuselage; nosewheel, which has hydraulic steering, retracts forward. Mainwheel tyres size 561x169, pressure 6.90 bar (100 lb/ sq in). Chinese hydraulic disc brakes. Anti-skid units. Minimum ground turning radius 6.69 m (21 ft 11 1/2 in).

POWER PLANT: Including prototypes, all except JL-8 have one 16.01 kN (3,600 lb st) Honeywell TFE731-2A-2A turbofan with Lucas Aerospace FADEC, mounted in rear fuselage. Production JL-8 for China powered by 16.87 kN (3,792 lb st) ZMKB Progress AI-25TLK turbofan, ordered in 1997; initial batch of 58 imported.
Fuel in two flexible tanks and one inverted flight tank in fuselage and one integral tank in wing centre-section, combined capacity 1,000 litres (264 US gallons; 220 Imp gallons); single refuelling point in fuselage. Provision for carrying one 250 litre (66.0 US gallon; 55.0 Imp gallon) drop tank on outboard pylon under each wing. Oil capacity 4 kg (8.8 lb).

ACCOMMODATION: Instructor and pupil in tandem, on Jianghan TY7A zero/zero ejection seats (Martin-Baker Mk 10L in Pakistan aircraft); rear seat elevated 28 cm (11 in). One-piece wraparound windscreen; two-piece canopy opens sideways to starboard. Cockpits pressurised and air conditioned.

SYSTEMS: Honeywell ECS 51833 air conditioning and pressurisation system, with maximum differential of 0.27 bar (3.9 lb/sq in). Hydraulic system, pressure 207 bar (3,000 lb/sq in), for operation of landing gear extension/retraction, wing flaps, airbrake, aileron boost, nosewheel steering and wheel brakes. Flow rate 15 litres (3.96 US gallons; 3.30 Imp gallons)/min, with air-pressurised reservoir, plus emergency back-up hydraulic system. Abex AP09V-8-01 pump. Electrical systems powered by 12 kW 28.5 V DC generator (primary) and 24 V DC (auxiliary), with 115/26 V single-phase AC and 36 V three-phase AC available from 40 Ah Ni/Cd battery and two static inverters, both at 400 Hz. Liquid oxygen system for occupants. Demisting of cockpit transparencies.

AVIONICS: Comms: Bendix/King KTR 908 VHF or KTR 909 UHF; intercom; FJ-20 flight data recorder.
Flight: Bendix/King KNR 634A VOR/glideslope/MKR with KA 26 beacon receiver, ADF 462, Type 265 radio altimeter, HZX-4A AHRS, SS/SC-5 air data computer and KTU 709 Tacan or WL-7A radio compass.
Instrumentation: Rockwell Collins EFIS-86T in first 100 aircraft, incorporating CRT primary flight and navigation displays for each crew member plus dual display processing units and selector panels for tandem operation. Blind-flying instrumentation standard. Standby flight instruments include ASI, rate of climb indicator, barometric altimeter, emergency horizon and standby compass. HUD under development.

ARMAMENT (optional): One 23 mm gun pod under centre-fuselage; self-computing optical gunsight in cockpit, plus gun camera. Two external stores points under each wing. Twin ejector racks on inboard stations can carry total of four 6, 11.5 or 50 kg practice bombs: single-store outboard stations can each carry a PL-5E air-to-air missile, a 12-round pod of 57 mm rockets, a 200 kg, 250 kg or BL755 bomb, or a drop fuel tank.

 

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