[WWII] Heinkel He 115 floatplane (Germany)

[copeab]

Heinkel He 115 floatplane

Copyright 2011 by Brandon Cope

The He 115 was a twin-engine, twin float seaplane designed for reconnaissance and attack and began replacing the He 59 (p.WWII:TFH51) starting in 1938. It was a very effective floatplane for the Germans and, although production ceased in 1941, lines were reopened in 1943 to build an improved model. They were used to mine British coastal waters early in the war (including the River Thames) and were important in attacking Arctic convoys to Russia (operating from bases in Norway).

About 500 He 115's of all types were built. Aside from those operated by Germany, Sweden and Norway, a small number were used by the British (4, via the Norwegians, and used for clandestine operations, mostly in the Mediterranean) and the Finns (3, one captured from Norway and two bought from Germany).

The He 115B-1 had a crew of three: pilot, observer/gunner (who manned the nose MG), and a radio operator/gunner/observer (who manned the dorsal MG). The He 115B-1 uses 58 gallons of aviation gas at routine usage.

Subassemblies: Heavy Fighter-Bomber chassis +3, Heavy Fighter-Bomber Wings +3, two Small AFV Engine Pods [Wings:F] +2, two sealed Medium TD pontoons [Body:U] +2, two fixed skids +1.
Powertrain: 2¥645-kW HP aerial gasoline engines with 645-kW props [Pod#1-2] and 960-gallon standard fuel tanks [Wings and Body]; 2¥2,000-kW batteries
Occupancy: 3 CS Cargo: 12 Body

Armor
All: 2/3

Weaponry
Aircraft LMG/MG 15 [Body:F] (600 rounds)
Aircraft LMG/MG 15 [Body:B] (1,500 rounds)

Equipment
Body: Long range radio transmitter and receiver, precision navigation instruments, autopilot, inflatable liferaft, 2,400-lb bomb bay, 12 VSP cargo, 1,800-lb hardpoint. Wings: 550-lb hardpoint each.

Statistics
Size: 57'x73'x22'
Payload: 5 tons
Lwt: 11.46 tons
Volume: 640
Maint.: 27 hours
Price: $55,800

HT: 8.
HPs: 325 Body, 300 each Wing, 225 each Pontoon, 150 each Engine Pod.

aSpeed: 203
aAccel: 3
aDecel: 18
aMR: 4.5
aSR: 2
Stall: 56
-1 mph per loaded hardpoint.

wSpeed: 25
wAccel: 4
wDecel: 10
wMR: 0.1
wSR: 2
Flotation Rating 14 tons.

Design Notes
Design speed was 188 mph. The historical wing area of 942 sf has been used. The weight (and thus cost and HPs) of the pontoons and wings were divided by two to reduce weight. Loaded weight was reduced by 13%.

Aside from up to five 550-lb bombs (two underwing and three internally), the He 115 could carry a parachute deployed mine (one TMA or two LMAs) or a torpedo. Mines were fitted in the bomb bay and the torpedo was carried underfuselage (blocking the bay doors).

The cargo space (between the pilot and radio operator) was normally left empty, but sometimes two men and an inflatable were carried there, for covertly landing agents. A third man could be crammed in, but the dingy had to be relocated to a compartment in the starboard float. The rest of the empty space of the design (34 VSP) should be mostly ignored.

At maximum load, the plane needs a 9 mph headwind to take off. With hardpoints and bay empty, it needs a 6 mph headwind.

Variants
The 10 preproduction He 115A-0's (1937) deleted the nose gun of the prototypes. The production A-1 added the nose MG 15 back. The A-2 was an export version, sold to Norway (6) and Sweden (12, designated T-2). The A-3 was the first version built in large numbers for the Germans. Fuel tankage was only 560 gallons.

The B-2 had the pontoon undersurfaces reinforced for operation from snow and ice.

The He 115C-1 (1941) had increased armament, with a 20mm MG 151/20 (20mm Medium Aircraft AC) in a pod under the nose and replacing the MG 15's with MG 81Z's. Two MG 17's were added to the rear of the engine nacelles firing to the back. The bomb bay was adapted to take bombs or an auxiliary fuel tank. The C-2, like the B-2, had reinforced floats and the C-3 and C-4 were optimized for minelaying and torpedo attack, respectively. The C-4 reduced gun armament to the dorsal MG 15.

The lone D-0 was a A-1 frame fitted with 1,193-kW engines (248 mph).

The He 115E-1 (1943) replaced the MG 15's with MG 81Z's. Some had a MG 151/20 under the nose. 141 built.

[adm]

I have always thought this plane looked very elegant.

Typo "lines were reopened in 1843".

[Phaelen Bleux]

Originally Posted by copeab

began replacing the He 59 staring in 1938.

Which I had planned to be my October Biplane of the Month. Creepy.

[copeab]

Originally Posted by Phaelen Bleux

Which I had planned to be my October Biplane of the Month. Creepy.

It's already in a WWII book -- Their Finest Hour.(p.51).

[Phaelen Bleux]

Originally Posted by copeab

It's already in a WWII book -- Their Finest Hour.(p.51).

Oops. Thanks for that.