It's an autogyro used as a towed aerial platform to provide longer-range surveillance to sufraced U-boats.
In the UK we tried the "Hafner rotabuggy" as a strap-on rotor system to turn a jeep into and autogyro for air-deploying the jeep. The tail and rotor system were to be removed after landing:
The same guy came up with the "Rotochute" as a system for getting a soldier plus full kit (more kit than a contemprary paratrooper) and ammo into hostile territory:
You name it, it's been tried...
PDR