DevelopmentIn 1930, Ernst Heinkel began developing an aircraft for the Reichsmarine. To conceal the true military intentions, the aircraft was officially a civil aircraft. The He 59B landplane prototype was the first to fly, an event that took place in September 1931,[1] but it was the He 59A floatplane prototype that paved the way for the He 59B initial production model, of which 142 were delivered in three variants. The Heinkel He 59 was a pleasant aircraft to fly; deficiencies noted were the weak engine, the limited range, the small load capability and insufficient armament.
The aircraft was of a mixed-material construction. The wings were made of a two-beam wooden frame, where the front was covered with plywood and the rest of the wing was covered with fabric. The box-shaped fuselage had a fabric-covered steel frame. The tail section was covered with lightweight metal sheets.
The keels of the floats were used as fuel tanks - each one holding 900 L (238 US gal) of fuel. Together with the internal fuel tank, the aircraft could hold a total of 2,700 L (713 US gal) of fuel. Two fuel tanks could also be placed in the bomb bay, bringing the total fuel capacity up to 3,200 L (845 US gal). The propeller was fixed-pitch with four blades.
General characteristics
Crew: 4
Length: 17.40 m (57 ft 1 in)
Wingspan: 23.70 m (77 ft 9 in)
Height: 7.10 m (23 ft 3½ in)
Wing area: 153.2 m² (1,649 ft²)
Empty weight: 5,010 kg (11,023 lb)
Loaded weight: 9,119 kg (20,062 lb)
Powerplant: 2 × BMW VI 6.0 ZU water-cooled V12 engines, 492 kW (660 hp) each
Performance
Maximum speed: 221 km/h (119 knots, 137 mph) at sea level
Cruise speed: 185 km/h (100 knots, 115 mph)
Range: 942 km (509 nmi, 585 mi)
Ferry range: 1,530 km (826 nmi, 950 mi) with auxiliary tanks
Service ceiling: 3,500 m (11,480 ft)
Climb to 1,000 m (3,300 ft): 4.7 min
Climb to 2,000 m (6,600 ft): 11.2 min
Armament
Guns: 3 × 7.92 mm (.312 in) MG 15 machine guns in nose, dorsal and ventral positions
Bombs: 2× 500 kg (1,100 lb) or 4 × 250 kg (55 lb) or 20× 50 kg (110 lb) bombs or 1 × 800 kg (1,764 lb) torpedo
