[Marcel Hogenhuis]

Hello Dan,

Recent attempts to find (the) other Ersatzteilliste have been fruitless so far but I am not giving up all hope. I am still hoping that constructional differences between the wings of an A-0, A-2 or A-7 can be found when we were able to compare the drawings of the wings.

In advance of that, we should ask ourselves what could have provoked Heinkel to redesign the wings each time? For the A-7 we have one major difference with the older A-0 and A-2: the wish to power the A-7 with a so called Einheitstriebwerk, whether that be the ill fated Jumo222, DB603 E or G or the Jumo213.
We further know that in many - if not most - German aircraft the engines were mounted between two strong bearers but not the He219: here the engines were attached to several attachment points as part of the skin. An interchangable Einheitstriebwerk (DB or Jumo213) could mean, that the construction of the engine gondolas as part of the wing had to be redesigned and perhaps strengthened.

This is just brainstorming: same construction numbers for each subtype at least suggests that these lived on with minor to no alterations (the modified air intakes for example); different construction numbers however strongly suggest that a redesign was neccessary for some important reason and new types of engines could be such reasons. Yet, the exact differences between the designs must still be found.

All the best, Marcel