Hi Wilbur,
>Cool vids v2 was the small one electric?
No, the Bachstelze (Wagtail) was in fact unpowered and could only sustain flight because it was towed by the U-boat.
The main problem was that if the U-boat was forced by an enemy threat to dive, the tow rope had to be cut and the pilot could not be recovered.
The German pilot interviewed in the video remarks that it was a "Himmelfahrtskommando" - best translated as "forlorn hope", I believe.
Regards,
Henning (HoHun)