I think on a busy frequency 'request' should be used - then I can decide when I want the pilot to ask me something. If I am busy, you will have to wait. Controllers do a myriad of other things as well as transmitting on R/T... simply blurting out a request (which will probably involve some non standard R/T) will probably lead to the controller saying "Station calling XXX say again, I was on the phone (etc)"
055166k using "
go ahead request" is not good (nor safe) R/T practice, "pass your message" is the correct response (and safe)!!
