Abbreviated Call Signs

“N2277TW climb and maintain TREE thousand” “Climb TO THREE SEVEN Tango Whisky” - Pilot not realizing they just said to climb to 23,700 feet

Aircraft callsigns on radios are probably the most critical element of any transmission. Who you are must be clear, undoubtable and unmistakeable. Ok, they’re important. In our day we’ve normalized the incorrect abbreviation of tail numbers - and since my CFII Dr. Bill beat me up about it pretty aggressively, I’ll do the same to you with this article. 

The AIM covers radio calls in chapter 4 (Air Traffic Control) section 2 (Radio Communications Phraseology and Technique). A pilot-controller glossary is also available to pilots at this link, which is referenced in FAA Order JO 7110.65 “Air Traffic Control” - the ATC Bible. It is beneficial to learn the proper terminology to avoid informalities and keep communications formal and professional. Terms like “Roger”, “WILCO”, “Affirmative” and so forth are there for a reason, and should be used appropriately. 

The aircraft’s call sign is the tail numbers, and should be read in full, especially upon initial contact [AIM 4-2-1 (a)(1)(b)]. Let’s use N227TW as the example. 

“NOVEMBER TWO TWO SEVEN TANGO WHISKY”

Alternatively, the NOVEMBER may be dropped in lieu of the Aircraft manufacturer/model [AIM 4-2-4 (a)(3)]. For example, 

“SKYHAWK TWO TWO SEVEN TANGO WHISKY”

ATC may abbreviate your call sign if they deem it safe (i.e., there aren’t any other callsigns that could be confused with yours) by only using the prefix (NOVEMBER or AIRPLANE MANUFACTURER) and the last three digits of your tail number [AIM 4-2-4 (a)(2)]. For example:

“N227TW” becomes “N7TW”:

“NOVEMBER SEVEN TANGO WHISKY”

or

“SKYHAWK SEVEN TANGO WHISKY”

You will hear pilots using the last three digits without any prefix - that is against the AIM and improper (i.e., “SEVEN TANGO WHISKY” instead of “NOVEMBER SEVEN TANGO WHYSKY” or “SKYHAWK TANGO WHISKY”. It’s important that we keep the N or the airplane’s manufacturer in the call sign to separate other numbers from our tail number. Altitudes, headings, and more should be obviously distinct from our tail number. Having too many numbers next to each other in a radio call can cause confusion to both sides, pilots and ATC.

As much as it may be very obnoxious of me emphasizing this (to the point of writing an article), the FAA has expressed their expectations, and us not following them is a normalization of deviance - because this is a safety-related guidance. Dr. Bill drilled this into my head, and I will drill it into my students’ minds as well.