Approved RT terminology may seem tedious and unnecessarily pedantic, but it is like that for a very good reason.
Many incidents and accidents have been caused over the years owing to misunderstandings between ATC and pilots. Use of the standard terms is safer because their meaning is defined and cannot be confused. It must also be borne in mind that transmission and reception is not perfect. Radios can be distorted or suffer interference, and cockpits can be very noisy places. As Basil suggests, the pilots are often very busy doing several things at once.
ATC need to remember that they are a SERVICE and are ASSISTING the aircraft pilots. The aeroplane comes first, not the controller wishing to clear a strip off his tray quickly.
Also we must bear in mind that pilots or ATC may not have English as their first language, which is another good reason not to speak too quickly. We had a discussion with Turkish ATC about something the other night and the person did not understand our conversational English at all, although that same ATC operator could control us in English perfectly well.
Going to Mexico a little while ago, the controller gave us a QNH of "993". We thought that odd as we were expecting inches of mercury and queried it several times. It later transpired that the controller had meant "29.93" but was using his own verbal shortcut by dropping the 2 and the decimal.
In this case the error didn't kill us, but it might easily have done.
Last edited by Uplinker; 17th Jul 2013 at 09:18.