[Mike Watson]

Hi. I do not have any books specifically on these types but Seeflieger (Adam Thompson) and Les Hyradavions de la LW Vols 1 and 2 (Roba and Neulen) do a good job of explaining the issues with respect to the obsolesence of the Do18 and the capbilities of the Bv138. I also have not seen Eric Browns reports on the Do18/Bv138 (I only have the 1977 Book) but would see no reason to doubt him. The fact that the Do18 was nicer to fly does not however mean that the Bv138 did not represent a considerable enhancement in operational capability.

With respect to performance figures you refer to I find that a number of sources do not provide equivalent data in particular for range/endurance. I have put together the following from a range of sources. There are some gaps for the Do18 - maybe someone else can fill them in. Hope it helps clarify the differences in this area at least.