Ravendriver said:
"Decimal" is used because the rest of the world uses it as an ICAO SARP, plus it is required in the AIPs (FARs) in most countries.
I know I am going to hear from FN FAL "who gives a F about ICAO," but if you fly outside the Americas you will be chastised on the radio for not saying "decimal" and you will then look very unprofessional.
This is why you hear "decimal" in the U.S. because it is the standard phraseology just about everywhere else.
Ducking, incoming........:uzi:
I work at the "Crossroads of the Pacific", and we get pilots from all over flying through. They like to say decimal at times, and might even (gasp!) request "QNH". All part of the game, no big deal - gotta be flexible. "With you" or "checking in", kind of a waste, but not worth getting any adrenalin running over. "AAAnnnnnd...." I think is kind of a verbal placeholder, brain is not yet engaged, or is engaged doing something else - "Airplane 123 , descend and maintain FL240". "AAaaaannnnd (while putting coffee down, spinning altitude alerter knob to 240) Airplane 123, down to FL240". I've done it: "Airliner 123, the Podunk altimeter iiiiiiiiiiiiiiiiiiiiiiissssssssssssss.... (oops, info display is on the wrong page, where's the podunk altimeter... there!) ...30.01". Could be planned better, but we are still human.
The only time I REALLY HATE "with you" or "checking in" is when someone I have not been talking to is calling out of the blue to request some service. "Center, Cherokee 13579 with you." The leaves me looking for some Cherokee I should be expecting, but I don't know about, generating a long pause while I figure out if I should know you. Crisp and to the point is the name of the game:
"Center, Cherokee 13579 4 west of Podunk, request radar advisories to Broken Buffalo."
"Center, Cherokee 13579 just departed Tedium, requesting IFR clearance to Apathy."
Checking in with altitude - yes, do it please, either level or altitude leaving and assigned:
2. The following phraseology should be utilized by pilots for establishing contact with the designated facility:
(a) When operating in a radar environment: On initial contact, the pilot should inform the controller of the aircraft's assigned altitude preceded by the words "level," or "climbing to," or "descending to," as appropriate; and the aircraft's present vacating altitude, if applicable.
EXAMPLE-
1. (Name) CENTER, (aircraft identification), LEVEL (altitude or flight level).
2. (Name) CENTER, (aircraft identification), LEAVING (exact altitude or flight level), CLIMBING TO OR DESCENDING TO (altitude of flight level).
It acts as a verbal reminder and is really good for my own SA, probably everyone else's, too. I looked for the part about verifying Mode C on initial contact with departure in the AIM, but couldn't spot it, here's my book:
5-2-17. VALIDATION OF MODE C READOUT
Ensure that Mode C altitude readouts are valid after accepting an interfacility handoff, initial track start, track start from coast/suspend tabular list, missing, or unreasonable Mode C readouts.
and
a. Consider an altitude readout valid when:
1. It varies less than 300 feet from the pilot reported altitude...
This is indeed a regular topic, even though I haen't been on here that long!