Hi, Stig.
I think this is a misprint. According to my data, L.G. 1 did not suffer a loss on 18.09.1943.
The IV./K.G.54 loss is recorded as follows:
http://www.ahs.no/ref_db/lw_loss_pub...?lossid=107102
The L.G.1 losses coming closest are:
I. Gruppe:
A loss on 19.09.1943, but that was at the airport at Prag (Praha)
II. Gruppe:
No losses between 18.08.1943 and 06.11.1943
III. Gruppe:
Closest losses in time are two aircraft that collided in the air at Münster-Handorf on 21.09.1943
IV. Gruppe:
Had one loss on 17.09.1943 (WNr 3910) that made an emergency bellylanding due to engine trouble, and a loss on 16.09.1943, when WNr 3978 was damaged 75% when it flipped over on landing, also at Wiener-Neustadt.
Regards,
Andreas