A H6K2-L Navy Transport Flying Boat Type 97 H6K1 Evaluation prototypes with four Nakajima Hikari 2 engines, 4 built. H6K1 (Navy Flying Boat Type 97 Model 1) Prototypes with 746 kW 1,000 hp Mitsubishi Kinsei 43 Engines, 3 converted from the original H6K1 prototypes. H6K2 Model 11 First production model. Includes two H6K2-L officer transport modification, 10 built. H6K2-L (Navy Transport Flying Boat Type 97) Unarmed transport version of H6K2 powered by Mitsubishi Kinsei 43 engines, 16 built. H6K3 Model 21 Modified transport version of H6K2 for VIPs and high-ranking officers, 2 built. H6K4 Model 22 Major production version, modified H6K2 with revised weapons, some with 694 kW (930 hp) Mitsubishi Kinsei 46 engines. Fuel capacity increased from 7,764 L (1,708 Imp gal) to 13,410 L (2,950 Imp gal). Includes two H6K4-L transport versions, 100 to 127 (if other numbers are all correct) built. H6K4-L Transport version of H6K4, similar to H6K2-L, but with Mitsubishi Kinsei 46 engines, 20 built and another two converted from the H6K4. H6K5 Model 23 Fitted with 969 kW (1,300 hp) Mitsubishi Kinsei 51 or 53 engines and new upper turret replacing the open position, 36 built.
Specifications (H6K4)
Data from Warplanes of the Second World War, Volume Five: Flying Boats;[3] Japanese Aircraft of the Pacific War[7]
General characteristics
Crew: 9
Length: 25.63 m (84 ft 3 in)
Wingspan: 40.00 m (131 ft 2 in)
Height: 6.27 m (20 ft 6 in)
Wing area: 170 m2 (1,830 ft2)
Empty weight: 11,707 kg (25,755 lb)
Loaded weight: 17,000 kg (37,400 lb)
Max. takeoff weight: 21,500 kg (47,300 lb)
Powerplant: 4 × Mitsubishi Kinsei 43 or 46 14-cylinder, air-cooled, radial engines, 746 kW (1,000 hp) each
Performance
Maximum speed: 331 km/h (211 mph)
Cruise speed: 216 km/h (138 mph)
Range: 6,580 km (4,112 mi)
Service ceiling: 9,610 m (31,520 ft)
Rate of climb: 370 m/min (1,213 ft/min)
Wing loading: 100 kg/m2 (20 lb/ft2)
Power/mass: 0.17 kW/kg (0.11 hp/lb)
Armament
1× 7.7 mm (0.30 in) Type 97 machine gun in nose
1× Type 97 machine gun in spine
2× Type 97 machine guns in waist blisters
1× 20 mm Type 99 cannon in tail turret
2× 800 kg (1,764 lb) torpedoes or 1,000 kg (2,205 lb) of bombs
