For Bf 109 experts: oil filler hatch

[Roger Gaemperle]

Hello,

The vertical position of the oil filler hatch behind the propeller spinner indicated which type of oil tank was mounted on the Bf 109.

A lower position just on top of the first air scoop indicates a 36 litres oil tank with a horseshoe shape, which is usually associated with the DB 605A or AS.

A higher position (c.20 cm or 6.5 inches over the air scoop) indicates a 50 litres oil tank of annular shape, which is usually associated with the DB 605D.

Now, here is my question: on several Bf 109 G-14 I have seen that the lower oil filler hatch is installed, but interestingly a clearly visible outline of the higher hatch position is present. An example of such a photo can be found in Prien/Rodeike 'Messerschmitt Bf 109 F,G,&K Series - An illustrated Study' by Schiffer Publications on page 160 at the top (Uffz. Gerd Hauter next to 'White 41' of Jagdgruppe Ost). If you look just above the oil filler hatch, you can see part of this outline. It is also visible on several other Bf 109 G-14/AS aircraft.

One theory by me, which may be totally wrong, could be that holes for both the lower and higher position of the oil filler hatch were added to the sheet metal that covered the nose and that during assembly one of them was covered by sheet metal and the other one by a hatch. This way, that nose could accommodate both oil tanks / engine types, which would have made sense from a production efficiency / simplification standpoint of view.

What is the view of the Bf 109 experts out here? Maybe this feature has been known already and there is an easy explanation.

Happy 2015 to all,

Roger