All I could guess at would be that this was probably in the early to mid-1920s. I doubt that any particular fighter was designed specifically to have transmitter/receiver equipment installed, but that greater interest was probably the driver, and industry would have attempted to meet the requirements. Come to think of it, answer (or at least the RAF answer - cannot vouch for any other country, and there could well be several contenders) may lie in the RAF WW2 Narratives, of which I have photocopies somewhere, which details the improvements and developments of airborne wireless apparatus (as it was known then!) I think there were about 6 volumes in this series, the one in question being "Aircraft radio". Not quite certain where my copies are at moment (result of a massive convulsion in my life - moving house 6 months ago), so perhaps somebody else on this forum has easy access to these wonderful reference books.