| He 115 | |
|---|---|
 Finnish Air Force He 115 N | |
| General information | |
| Type | Torpedo bomberseaplane |
| Manufacturer | Heinkel |
| Status | Retired |
| Primary users | Luftwaffe |
| Number built | 138 |
| History | |
| Introduction date | 1939 |
| First flight | August1937 |
TheHeinkel He 115 was an all-metal twin-engined militaryseaplane designed and produced by theGerman aircraft manufacturerHeinkel. Early on its flying history, the He 115 established several new international records for floatplanes.[1]
The He 115 was developed during the latter half of the 1930s in response to a requirement issued by the GermanReichsluftfahrtministerium (RLM). Heinkel opted to design a three-seat seaplane that could function as atorpedo bomber,reconnaissance aircraft andminelayer. The initial model of the aircraft, the first prototype of which performed itsmaiden flight in August 1937, was powered by a pair of 960 PS (947 hp, 720 kW)BMW 132K nine-cylinder air-cooledradial engines. Subsequent models varied in several respects, such as being equipped with different engines or alternative armament arrangements, increased fuel capacity or payload, and some He 115s could even accommodate an additional crew member.
The He 115 saw active combat with multiple operators, particularly during its service with theLuftwaffe during theSecond World War. Early on in the conflict, German He 115s frequently deployed mines within British waters. It proved itself to be a capable anti-shipping platform, particularly againstArctic supply convoys. Other nations flew the He 115, the majority beingScandinavian. TheRoyal Norwegian Navy Air Service operated a number that flew missions againstthe German invasion of Norway; several survivors escaped the occupation by flying to the UK, where they continued to be flown against the Germans until they were lost. By the twenty-first century, while a few airframes have survived, none are currently on display to the public and none are flightworthy.
The origins of the He 115 can be traced back to 1935 and the issuing of a requirement by the GermanReichsluftfahrtministerium (RLM) that called for a twin engined general purposefloatplane, suitable for maritime patrol and anti-shipping strikes with both bombs andtorpedoes. Numerous aircraft manufacturers responded with their own proposals, including Heinkel Flugzeugwerke and theBlohm & Voss aircraft subsidiaryHamburger Flugzeugbau. On 1 November 1935, orders were placed with both Heinkel and Hamburger Flugzeugbau to produce threeprototypes of their prospective designs, designated theHe 115 and theHa 140 respectively.[2][3]
In terms of its general configuration, the He 115 was an all-metal mid-wingmonoplane with amonocoque fuselage.[4] It was equipped with a pair offloats, each of which was attached to the underside of the enginenacelles via a largestrut. The twin-spar wing was built in three sections.[4] It featured a stepped cockpit along with a rear-facing observation compartment.[5] Initially, the He 115's armament consisted of two 7.92 mm (.312 in)MG 15 machine guns, one in the nose and one in the dorsal position.[2] On later-build He 115s, the typical armament fitted included a fixed forward-firing 15 mm or 20 mmMG 151 cannon and two rearward-firing 7.92 mm (.312 in)MG 17 machine guns in the engine nacelles.[6][7] Furthermore, some variants carriedLTF 5 orLTF 6b torpedoes andSD 500 500 kg (1,100 lb) orSC 250 250 kg (550 lb) bombs, while others carriedLMB III orLMA mines.
During August 1937, the first prototype He 115 performed itsmaiden flight.[8] Flight testing went relatively smoothly, the type's flight characteristics proving to be quite favourable.[4] In early 1938, the He 115 was selected over the rival Ha 140, thus securing a second order for another prototype and 10 pre-production aircraft.[2] According to aviation historian Hans Amtmann, Hamburger Flugzeugbau did not have enough spare manufacturing capacity for series production and declined the order, leading to Heinkel's selection instead.[9] During March of that year, the first prototype was used to establish a series of international records for floatplanes over 1,000 km (620 mi) and 2,000 km (1,200 mi) closed circuits at a speed of 328 km/h (204 mph).[1] Prior to these records being set, the prototype had been modified to achieve greater aerodynamic performance, such as the deletion of the angular glazed nose and the rear compartment, which were replaced byfairings.[8]
The third and fourth prototypes including a continuous glazed canopy (between the windshield and the rear position) and angledbracing struts between the vertical struts attached to the floats respectively.[8] In 1937, ten pre-production He 115s were completed; deliveries of production standard aircraft to theLuftwaffe commenced one year later. The He 115A-3 was the first variant to be produced in quantity, it differed from earlier models by having a revisedbomb bay and radio apparatus. During 1939, the improved HE 115B-1, which featured a more than 50 percent increase in fuel capacity, was introduced.[8]
While production came to an end during the first half of theSecond World War, the He 115 was highly regarded, to the extent that production was resumed in 1943, despite an increasingly large proportion of German's aircraft manufacturing capacity being allocated to defensivefighter aircraft instead.[10]
Throughout the Second World War, the primary mission of the Luftwaffe's He 115s was to conduct minelaying, typically during night time to lower the likelihood of interception.[4] Following the first such mission on 20 November 1939, the He 115 was frequently used for dropping (typically viaparachute)magnetic mines in British waters, normally aiming for narrow passages close to busy ports on the English south coast; theRiver Thames was also a prime target. These mining efforts supplemented the efforts of theKriegsmarine.[11] The island ofSylt was used as a base for He 115s performing these missions; in response, it became a target forAllied bombing missions.[12]
Perhaps the most effective missions performed by the He 115 were its anti-shipping operations againstArctic convoys, for which it operated out of bases inoccupied northern Norway. Due to early convoys lacking any air cover, the slow and lightly-armed He 115 was less vulnerable during these attacks than it was when operating near to the English coast. Following the appearance ofcarriers andescort carriers, coupled with the arrival of new Sovietheavy fighters like thePetlyakov Pe-3bis,Luftwaffeair superiority over the convoys was challenged and losses increased.[citation needed]
Apart from its use as aminelayer and torpedo bomber, the He 115 was used for coastal reconnaissance and byKG 200 to drop agents behind enemy lines.[13]
_F.60_of_the_Royal_Norwegian_Navy_Air_Service.jpg)
In response to the rising tensions in Europe, theNorwegian Ministry of Defence had ordered six He 115Ns for theRoyal Norwegian Navy Air Service (RNoNAS) on 28 August 1939 and the aircraft were delivered from 14 July – 13 November 1939.[14] The He 115N order was intended to replace the RNoNAS fleet of 1920s vintageDouglas DT torpedo bombers and the obsolescentMarinens Flyvebaatfabrikk M.F.11, which was the mainstay of the RNoNAS in 1940.[15] The Norwegians signed another order of six He 115Ns in December 1939, with delivery expected in March/April 1940 but this was forestalled byOperation Weserübung, the German invasion of Norway of 9 April 1940.[14] 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 atSola andFlatøy in the south to the one atSkattøra Naval Air Station outsideTromsø in the north. At the beginning of the German invasion, the aircraft at the seaplane base atHafrsfjord nearStavanger (F.60) was captured by the Germans, but twoLuftwaffe He 115s (given the codes F.62 and F.64 in Norwegian service) were seized by an improvisedmilitia unit of Norwegianriflemen atØrnes inGlomfjord,Nordland and bypolice officers atBrønnøysund, 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.[12]
Seven Norwegian He 115s, five of them He 115Ns, were employed against German and German-controlled ships (see:HNoMSUller), as well as providingground support to theNorwegian Army offensive on theNarvik Front. On 14 April 1940, three Norwegian He 115s made a successful attack on German Ju 52s atGullesfjordbotn. Four of the Norwegian aircraft (F.52, F.56, F.58 and F.64) made the journey to theUnited Kingdom shortly before the 10 June 1940 surrender,[12] a fifth (F.50) escaping toFinland, landing on Lake Salmijärvi inPetsamo.[16] A sixth He 115 (F.54) also tried to make the journey to Britain but was lost over theNorth Sea. The last of the Norwegian He 115s, F.62 (one of the two captured German aircraft), was unserviceable at the time of the evacuation and was abandoned at Skattøra, later being repaired and flown by the Germans.
The four escaped aircraft were reformed into the NorwegianHelensburgh Group underCommander Bugge.[12] The exiled NorwegianCabinet Nygaardsvold made plans shortly after arriving in Britain to use the four He 115s to performleaflet dropping missions over Norway. This leaflet mission was to deliver a declaration to theNorwegian people, stating the Norwegian authorities were re-established in the UK and rejected any Nazi German overtures for a German–Norwegian peace deal. All four Norwegian He 115s were ordered from Helensburgh to Scapa Flow on 3 July 1940 to carry out the mission, although one had to return to Helensburgh due to engine problems. The three He 115s assembled atScapa Flow were ordered to fly to Norway and drop the declaration over the cities ofOslo,Bergen andTrondheim. Shortly before the mission was to get under way, the BritishAir Ministry intervened and stopped the expedition, insisting that such an undertaking would be suicidal to attempt with the slow flying He 115s. Three days later, the aircraft returned to Helensburgh.[17]
Three of the Norwegian He 115s (F.56, F.58 and F.64) were subsequently used in covert operations off Norway and in theMediterranean Sea with Norwegian crews. In British service, the three received newserial numbers,BV184,BV185 andBV187.[14]BV184 was attacked and damaged by two PolishSpitfire fighters over theBay of Biscay in the spring of 1942, while co-operating with French fishing boats and later lost in a refuelling fire in the UK.[18][14]BV185 was destroyed in an Italian air raid onKalafrana,Malta after flying just one clandestine operation to North Africa.[14][12]BV187 flew several missions on the North African coast from its base in Malta before being destroyed by a pair of German Bf 109s.[14]
On 8 June 1940, the day after Norwegian forces were ordered to cease hostilities, one He 115 (F.50, deemed technically unfit to be flown to the UK), was flown to Finland posing as a civilian aircraft LN-MAB. The floatplane wasinterned but the pilot, experienced line captain and naval lieutenant Helge Dahl and crew were free to leave Finland. From Summer 1941, it was used by theLLv.14 of theFinnish Air Force code HE-115 and named "Jenny", to ferrySissi troops behind Soviet lines. In this role, it proved valuable in a terrain with numerous secluded lakes. It served in this role until ambushed inEast Karelia on 4 July 1943.Jenny took off but soon had to ditch and the crew was taken prisoner. Two days later the floating HE-115 was strafed by FinnishMorane-Saulnier MS.406 fighters. There are reports that the Soviets salvaged the wreck for evaluation.[14] A pair of Luftwaffe He 115 C were borrowed for similar operations in 1943–44 and operated with German markings by Finnish crew. One was returned in 1944 but the other was surrendered to the Soviets after the signing of theMoscow Armistice.[citation needed]
TheSwedish Air Force operated 12 He 115A-2s under the local designationT 2, with Air Force numbers 101–112. Another six aircraft were ordered but never delivered due to the outbreak of the Second World War. They were sturdy and well liked by their crews and were not taken out of use until 1952. The Swedish T 2s were kept on duty throughout the Second World War and made a valuable contribution to protecting and enforcingSwedish neutrality. The T 2s replaced the outdatedT 1s (Heinkel HD 16s) as torpedo bombers and also served as regular bombers, for smoke screening and for long-range reconnaissance missions. Five of the 12 T 2s were lost in accidents during their service with the Swedish Air Force.[19]
Five prototypes were used in the development of the aircraft,
The basic design of the aircraft remained unchanged during the type's career. The main differences, with a few notable exceptions, were changes in armament and avionics. Also to note is that the 'new' 'E' version, launched when production restarted in 1941, is in fact similar to the 'C'-series, again with the exception of armament changes.
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Data fromFighters and Bombers of World War II[23]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Related lists
