[Saurreg]

I read the BW's article and it's filled with many quotations from the books. However all of his deductions are assumed. There is no substantial concrete evidence that

a) balrogs had wings and could fly
b) balrogs had wings but cannot fly (dodo?!!)
c) Balrogs had no wings but its fiery smoke resembled wings.

I'm more inclined to believe opinion A given the description of the Balrogs' flight to rescue Morgoth. However this is ultimately an open-ended question. No definite answers whatsoever.