The Heinkel He 115 was a three-seat World War II Luftwaffe seaplane. It was used as a torpedo bomber and performed general seaplane duties, such as reconnaissance and minelaying. The aircraft was powered by two 960 PS (947 hp, 720 kW) BMW 132K nine-cylinder air-cooled radial engines. Some later models could seat four, had different engines or used different weapon arrangements.
Development and design
In 1935, the German Reich Air Ministry (RLM, Reichsluftfahrtministerium) produced a requirement for a twin engined general purpose floatplane, suitable for patrol and for anti-shipping strikes with bombs and torpedoes. Proposals were received from Heinkel Flugzeugwerke and from the Blohm & Voss aircraft subsidiary Hamburger Flugzeugbau. On 1 November 1935, orders were placed with Heinkel and Hamburger Flugzeugbau for three prototypes each of their prospective designs, the He 115 and the Ha 140.
The first prototype Heinkel flew in August 1937, testing was successful and the He 115 design was selected over the Ha 140 early in 1938, leading to an order for another prototype and 10 pre-production aircraft. The first prototype was used to set a series of international records for floatplanes over and closed circuits at a speed of .
Armament initially consisted of two 7.92 mm (.312 in) MG 15 machine guns, one in the nose and one in the dorsal position. Later He 115s were fitted with a fixed forward-firing 15 mm or 20 mm MG 151 cannon and two rearward-firing 7.92 mm (.312 in) MG 17 machine guns in the engine nacelles. He 115 variants carried LTF 5 or LTF 6b torpedoes and SD 500 or SC 250 bombs. Some also carried LMB III or LMA mines.
Operational history
Luftwaffe
At the outbreak of the war, the He 115 was used for dropping parachute mines in British waters, normally aiming for narrow passages close to busy ports on the English south coast; the River Thames was also a prime target. The aircraft had its finest moment on anti-shipping operations against Arctic convoys from bases in northern Norway. Because the first convoys lacked air cover, the slow and lightly armed He 115 was less vulnerable than near the English coast. With the appearance of carriers and escort carriers, coupled with new Soviet heavy fighters like the Petlyakov Pe-3bis, Luftwaffe air superiority over the convoys was challenged and losses increased.
Apart from its use as a minelayer and torpedo bomber, the He 115 was used for coastal reconnaissance and by KG 200 to drop agents behind enemy lines.
Royal Norwegian Navy Air Service
In response to the rising tensions in Europe, the Norwegian Ministry of Defence had ordered six He 115Ns for the Royal Norwegian Navy Air Service (RNoNAS) on 28 August 1939 and the aircraft were delivered from 14 July – 13 November 1939. The He 115N order was intended to replace the RNoNAS fleet of 1920s vintage Douglas DT torpedo bombers and the obsolescent Marinens Flyvebaatfabrikk M.F.11, which was the mainstay of the RNoNAS in 1940. The Norwegians signed another order of six He 115Ns in December 1939, with delivery expected in March/April 1940 but this was forestalled by Operation Weserübung, the German invasion of Norway of 9 April 1940. At the outbreak of hostilities, the RNoNAS had six He 115Ns in service (F.50, F.52, F.54, F.56, F.58 and F.60) spread along the coast from the naval air stations at Sola and Flatøy in the south to the one at Skattøra Naval Air Station outside Tromsø in the north. At the beginning of the German invasion, the aircraft at the seaplane base at Hafrsfjord near Stavanger (F.60) was captured by the Germans, but two Luftwaffe He 115s (given the codes F.62 and F.64 in Norwegian service) were seized by an improvised militia unit of Norwegian riflemen at Ørnes in Glomfjord, Nordland and by police officers at Brønnøysund, Nordland. The two aircraft were seized after they ran out of fuel and had to make emergency landings on 10 April. Manned by Norwegian aircrews, they served against their former owners for the duration of the campaign.