The Focke-Achgelis Fa 330 Bachstelze (Eng: Wagtail) was an unpowered rotor kite produced in 1942 by the Weser Flugzeugbau company and became operational in 1943 as a lookout for larger ocean-going German submarine Type IX U-boats. Due to the low profile of a U-boat the vision from the conning tower was not much more than 9 kilometers. As a lookout the gyrocopter could increase this visibility considerably.
U-boat lookout
When the gyrocopter was pulled by a moving U-boat, the draft made the rotors turn and created a lifting power. It got to max 120 meters high giving the spotter a 45 kilometer 360 degree vision around the U-boat. For communication between the pilot and the U-boat an interphone connection with a wire wrapped around the towing cable was used. In case of emergency, the rotor blades could be jettisoned by the pilot which pulled a parachute from a canister.
When not in use, the Focke-Achgelis was stored in watertight containers and set up by a crew of two in 4 minutes, in calm weather. In rough weather it took about 20 minutes to set the Bachstelze (Wagtail) up.
This Focke-Achgelis Fa 330 Bachstelze was photographed in Berlin at the Deutsches Technik Museum in 2016.
Thank you for all the excellent pictures of the BachStelze!