Recently, I've watched Air Force One and I heard ATC and the pilots say "Acknowledged." instead of "affirm" or "affirmative" as I've learned..
Is it common to say both? Or might "Acknowledged." just throw the controller / pilot off?
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Sign up to join this community"Acknowledged" means I heard you & understood what you said & I take responsibility for the information you just gave me.
"Affirm" and its opposite, "negative," are answers to a yes/no question.
They aren't really interchangeable, although Hollywood script writers are notorious for getting details like that wrong.
An example of correct usage would be, "Callsign 123, is your ride smooth at FL350?" "Callsign 123, affirm." (Answers the question, yes the ride here is smooth.") Then, "Callsign 123, we've had reports of light turbulence at your 12 o'clock and 100 miles." "Callsign 123, acknowledged." (Or, "roger" is more common, but same meaning... either way, I've received & understood the turbulence report.)
To reply "roger" or "acknowledged" to the question "is your ride smooth" is incorrect, because all you'd be saying is, I heard your question. There isn't any "yes" or "no" component to either of those replies. Likewise, to reply "affirm" to the "turbulence ahead" call is wrong because there was no question being asked there. The controller just needs to know that you heard the information so that it doesn't have to be repeated.
Interestingly, the FAA Pilot-Controller Glossary doesn't list "acknowledged" at all, but lists "acknowledge" as a directive: tell me that you heard me.
It also lists "affirmative" and not "affirm" -- that may be more used elsewhere. Also, with the quality of modern radios, the risk of the initial syllable(s) getting lost & the receiver left puzzling over "...ative" has probably diminished over time.
Movies frequently get pilot language wrong, and this is no exception.
In the UK, the phraseology bible is CAP 413 and that does not list the term "Acknowledged" as standard phraseology at all.
The phrase "ACKNOWLEDGE" can be used by the asker to:
Let me know that you have received and understood this message.
And is responded usually with:
Acknowledgements of information should be signified by the use of the receiving stations’ callsign or Roger callsign, and not by messages such as: ‘callsign-copy the weather’ or ‘callsign-copy the traffic’
The phrase AFIRM means
YES
One example in CAP413 has of the use of ACKNOWLEDGE is:
BIGJET 347, I am instructed by Her Majesty’s Government that you are to hold at KTN at FL270. Acknowledge
(How very British!)
Another is:
BIGJET 347, I am informed that there may be damage to the port wing tip of your aircraft. It appears that your planned flight is liable to endanger life. Acknowledge
Which does indeed feel like it needs the pilot to positively acknowledge that they have received the message. CAP413 is not explicit on what the response should be but I suspect it would simply be along the lines of
BIGJET 347, Roger, request taxi to stand.
Good question.
The appropriate term in aviation for "Acknowledged" is the term "Roger." The only time I hear the word "Acknowledged" is on Star Trek and other tv shows or movies. As mentioned above, "Acknowledged" is not a Pilot-Controller term, although a controller might ask you to "acknowledge" something he/she has said or asked, in which case you will respond with either the answer, or say Affirmative or Negative, or in some cases, just "Roger" (plus your tailnumber).
"Roger" simply means you have received the transmission. In other words, "Roger" is an acknowledgement of a transmission.
"Wilco" is rarely used, but it means "you have received the message and will comply", some old pilots combine the two in the redundant "Roger wilco."
"Affirm" is a non-standard, but widely used, abbrevication for "Affirmative." Which simply means yes. Usually pronounced "A-firm." It is the opposite of "Negative." Personally, I hate it when people use "Affirm" on the radio, but it's widely understood and controllers generally accept it in place of "Affirmative."
Don't use "Acknowledged" in place of Affirmative or Roger in aviation communication. Better yet, don't use "Acknowledged" at all in aviation. If you mean "yes" say "Affirmative." If you want to say you've received or acknowledged a transmission say "Roger."
Likewise, don't use "Copy" or "10-4" in place of "Roger."
Both are correct. "Affirm" is not non-standard.
ICAO uses "Affirm" to mean "Yes".
However FAA uses "Affirmative" to mean "Yes".
I have not been able to find any document that addresses whether it is proper or improper for pilots to use ICAO terminology in US airspace, but US controllers use FAA terminology.
ICAO Manual of Radiotelephony: www.ealts.com/documents/ICAO%20Doc%209432%20Manual%20of%20Radiotelephony%20(4th%20ed.%202007).pdf
FAA Pilot-Controller Glossary: https://www.faa.gov/air_traffic/publications/media/pcg_basic_with_change_1_2_and_3_dtd_11-3-22.pdf