Focke-Achgelis Fa 330A-1
History
The Fleet Air Arm Museum at Yeovilton displays one of the most unusual aircraft of the Second World War: the Focke-Achgelis Fa 330 Bachstelze. The Fa 330 was not a helicopter in the normal sense, but a lightweight rotary-wing "kite" designed by the German company Focke-Achgelis for use by the Kriegsmarine's U-boats during World War II.
The aircraft first flew in 1942 and was intended to solve a major problem faced by submarines operating on the surface: limited visibility. From the conning tower of a U-boat, the horizon could only be seen for a few miles. By towing the Fa 330 behind the submarine on a long cable, an observer could rise hundreds of feet into the air and spot ships or aircraft far beyond the normal visual range. The observer communicated with the submarine crew through a telephone line built into the tow cable.
The Fa 330 had no engine of its own. As the submarine travelled on the surface, airflow spun the rotor blades and lifted the craft into the air like a gyrocopter. The entire machine could be assembled quickly by the crew and stored in watertight containers when not in use. Around 200 examples were built during the war.
Although ingenious, the Fa 330 had serious drawbacks. Deploying it forced the submarine to remain on the surface, making the boat vulnerable to Allied aircraft and radar detection. If danger appeared suddenly, there was often no time to reel the observer back in, and the tow cable might have to be cut so the submarine could dive immediately. Because of these risks, the aircraft was mainly used in remote areas such as the Indian Ocean and the South Atlantic, where Allied air patrols were less common.
The example preserved at the Fleet Air Arm Museum is one of only a handful surviving worldwide. It is displayed in Hall 2 among other Second World War naval aviation exhibits, helping visitors understand the experimental and often desperate technologies developed during the Battle of the Atlantic. The museum itself, established in 1964 at Royal Naval Air Station Yeovilton, is Europe's largest naval aviation museum and preserves more than ninety aircraft connected with naval aviation history.