TYPE: Special mission versions of Metro III.

PROGRAMME: Development and production on demand.

VARIANTS: Maritime patrol: 360° scan Litton AN/APS-504(V), (V)5 or AIL AN/APS-128D radar in underbelly blister; Omega navigation linked to hand-held cameras; two bulged observation windows staggered one on each side of rear fuselage. Options include searchlight, IR linescanner, low light TV, FLIR, side-looking TV, Doppler radar, droppable liferafts, surival kits and two 288 litre (76 US gallon; 63 Imp gallon) underwing auxiliary tanks. At max T-O weight 7,257 kg (16,000 lb) with underwing tanks, surveillance variants can fly 10 hour mission over radius of 1,050 nm (1,946 km; 1,209 miles) from base at 7,620 m (25,000 ft) with 45 min fuel reserve.
Anti-submarine: Carries sonobuoys and sonobuoy signal processor, an OTP indicator, and MAD tailboom. Options as for maritime patrol variant.
Airborne early warning: Swedish Defence Materiel Administration (FMV) ordered Fairchild study of airborne early warning (AEW) version of Metro III in 1982, carrying dorsal active array radar antenna; initial wind tunnel testing by LTV in Dallas during 1983; FMV ordered Metro III to test Ericsson PS-890 (later FSR-890) Erieye early 1986; FSR-890 is fixed antenna, electronically scanned E/F band radar scanning to one side at a time over 120° arc; first flight with mockup antenna October 1986; delivered to Sweden after 116 hours aerodynamic and handling tests by Fairchild October 1987; exhibited at Farnborough Air Show 1988; first flight with operating radar due May 1991. Reported Swedish requirement for 10-15 aircraft, to enter service 1997-98; platform aircraft could be Saab 340 instead of Metro.
Antenna in composites housing approx 8 m (26 ft 3 in) long, mounted on pylons above fuselage with ram air cooling; antenna mounted at incidence -2° to allow for angle of attack at patrol speeds, auxiliary fins on tailplane; enlarged ventral fin; Turbomach T-62T APU, producing 60kVA electrical supply for radar, mounted in E-Systems pod on centreline pylon under wing; periscope sight in flight deck roof; larger emergency exit on port side of cabin. Data link to connect with Swedish STRIL 60/90 not selected.
Loiter speeds include 135-146 knots (250-270 km/h; 155-168 mph) with flaps at 50 per cent, 164-175 knots (305-325 km/h; 189-202 mph) with flaps at 25 per cent; endurance 4-6 h in patrol area 100 nm (185 km; 115 miles) away from base.
Other variants include flight inspection, photo reconnaissance, electronic intelligence and airborne critical care.

CUSTOMERS: Total 35 delivered in various configurations by 1991.