Although very well known, this photo taken on April 18, 1940 is invariably misleading ... 
It does not show a hypothetical Bf109E2 axial gun MGC/30 installed in the nose 
(this variant has never existed), but the so-called Bf109 E3 CE+BM WrkN1953 
[actually E4 CE+BM WrkN1779] testing an in-flight towing device to improve bomber escort 
for the future Sea Lion operation, the invasion of Britain. Piloted by Heini Dittmar, 
the WrkN1953 [WrkN1779] was towed that day by a BF110 C1 CE+BU WrkN959 piloted by 
Hermann Wurster from Augsburg to Munich-Riem, then back to Augsburg.

Although the test is successful because the Bf109 E arrives back to Augsburg and detaches itself 
in flight to land by its own means, the operation will not be continued in view of the development 
of the E7 variant capable of carrying an additional ventral fuel tank.

The bar that comes out of the hub of the propellor, and to which is hooked the towing cable, 
is indicated by the four letters G.Sch .: Geheime Schleppkupplung (attention to the coupling 
of the towing device). Modifying to E7, the WNr1953 now code "4 White" at 4.(Eins)/JGr.Drontheim 
will be lost on technical trouble on October 8, 1941 off Bud, Norway.

The Stammkenzeichen CE+BM was actually assigned to an E4 prototype shown by the description of 
this photograph. The Werke Nummer at the beginning of this document is wrong. It is actually 1779. 
The 1953 Werke Nummer was assigned to the new E7 made from this V20 prototype after the towing
tests. Technically, this aircraft had both Werke Nummers, but not at the same time.