[ballenato]

Thanks for reply, but that plane isn't a E-2, even a prototype.
That source is wrong (IICR the book is "Aerodetail 1 Messerschmitt BF109E"). The plane depicted is an E-3/4 Wrkn 5601 or E-3 5600* ( differents sources), and the so called "brast-tube" its just a towing system tested without too much success.

Here you have 2 better pics.





regards

*Edited: Wrkn from http://www.luftwaffe-experten.org/stam-c.html