single tail and repeated reversion how is this a constructive edit nor are these particularly helpful either just to remind a few people ip editors are allowed to edit when they're then reverted and requested to add sources nor should we be surprised if they then go and do exactly what they've been asked for it is self evident that the b had twin tails and the pb y had a single tail clearly is there some development history here and we should welcome coverage of that if anyone has issues of the details then please discuss that or even expand it with sources yourself no doubt the great and the good of the aircraft cabal are well supplied with such sources there is no excuse for repeated hostile reversion of a gf editor who is moving the article in a positive direction