@ Chris,
hence the certainly necessary
training.
This foldable piece of equipment was intended for observation tasks exclusively.
Any WWI biplane or zeppelin could have shot it down easily.
The challenge for the U-Boot crews was to get the equipment ready for take-off and to recover it as quickly as possible.
In fact, the device is merely a significantly enlarged lookout.
Marginal objection, the "Bachstelze" is a non-powered rotor kite, not a motor driven autogyro.
Please excuse this silly know-it-all remark, I just couldn't help it.