Focke-Achgelis Fa 330

https://en.wikipedia.org/wiki/Focke-Achgelis_Fa_330

Because of their low profile in the water, submarines could not see more than a
few miles over the ocean. To solve this, the German admiralty considered a
number of different options, including a folding seaplane (Arado Ar 231). In the
end, they chose the Fa 330, a simple, single-seater, autogyro kite with a
three-bladed rotor.

The Fa 330 could be deployed to the deck of the submarine by two people and was
tethered to the U-boat by a 150 m (500 ft) cable. The airflow on the rotors as
the boat motored along on the surface would spin them up. The kite would then be
deployed behind the U-boat with its observer-pilot aboard, raising him
approximately 120 meters above the surface and allowing him to see much farther
— about 25 nautical miles (46 km), compared to the 5 nautical miles (9 km)
visible from the conning tower of the U-boat. If the U-boat captain were forced
to abandon it on the surface, the tether would be released and the Fa 330
descend slowly to the water.

When not in use, the Fa 330 was stowed in two watertight compartments aft of the
conning tower. Recovering, dismantling, and stowing the Fa 330 took
approximately 20 minutes and was a difficult operation.

Role
Autogyro kite

Manufacturer
Focke-Achgelis GmbH

Number built
200

As Allied air cover in other theatres of the war was considered too much of a
threat, only U-boats operating in the far southern parts of the Atlantic and the
Indian Ocean used the Fa 330. Despite its advantages, the use of the Fa 330
resulted in only a single sinking when U-177 used one to spot, intercept and
sink the Greek steamer Efthalia Mari on 6 August 1943.

The Allies came into possession of an Fa 330 in May 1944 when they captured the
U-852 intact. After the war, the British government did successful experiments
towing Fa 330s behind ships and jeeps, but the development of the helicopter
quickly occupied the attention of the military.

U-boats that deployed Fa 330 kites included at least U-177, U-181, and U-852.
Otto Giese wrote, "Our boat was rigged with a Bachstelze. This was a small,
single, piloted helicopter attached to a long steel cable and lifted into the
air by the speed of the boat while the cable was gradually reeled out. From his
position aloft, the pilot had a 360-degree view and could report any vessels.

Specifications

General characteristics
Crew: 1
Length: 4.42 m (14 ft 6 in)
Empty weight: 68 kg (150 lb)
Main rotor diameter: 7.32 m (24 ft 0 in)
Main rotor area: 42 m2 (450 sq ft) 3-bladed rotor

Performance
Maximum speed: 40 km/h (25 mph; 22 kn) on tow
Minimum control speed: 27 km/h (17 mph; 15 kn) on tow




*