If you are holding an EASA ATPL(H) IR, how can you convert it into ATPL(A) and would you be able to credit your heli hours? As I've 400 hours and it would get longer to build hours with ATPL.
It looks like the answer is yes, but with some significant caveats, such as only 50% of your helo time will count towards a fixed-wing ATPL. The UK CAA web site has info on this but your best bet is to contact a reputable flight training organization that offers ATPL training. Click on the "Holders of a UK issued Part FCL licence in another category" link (there is no direct URL to this content). If the country in question is not the UK you should check their rules.