ORIGINAL: John Redman
Just for the note; it is a BF-109, not an ME-109.
Just for the note......ME-109 is just as correct as BF-109. Records by the RLM have BOTH designations, and often in the same paragraph. This has been a long heated debate, but in the end, whats in the RLM documents is what matters and both are used. BF was the intial designation due to the plane design being submitted via the company Bayerische Flugzeugwerke because Willy Messerschmitt wasnt exactly held in high regard by the RLM minister at the time. However, the company was renamed Messerschmitt AG after 11 July 1938 when Erhard Milch finally allowed Willy Messerschmitt to reacquire the company.
Hence forth, all new planes manufacturered carried the ME designation except those that had already been built. So there were both BF-109s and ME-109s side by side on the flightlines.
The 109 still had BF-109 stamped on the identication plates in many instances, but many also had me-109. Documents by RLM, Messerschmitt AG, and the Luftwaffe refered to the plane using both designations in most instances, such as strength and loss reports, etc.
A lot of planes re-fitted by Erla Flugzeugwerke carried the ME-109 stamping.
http://en.wikipedia.org/wiki/Me-109
http://www.wordiq.com/definition/Me-109