RE: What is a t14z form Futaba?
I think I saw in the Futaba forum that some sort of recalibration, that the end user cannot do, is required. If you already own the transmitter, it should be in the manual if you can do it. If it has to be sent in it costs 37.50 plus shipping for Hobby Services to do it.
edit - the Tower Hobbies page says it needs to be sent in for a mode change