SNFO/SWSO VOICE COMMUNICATIONS
Aircraft Call Signs
1. Improper or abbreviated aircraft call signs can result in aircrews executing a clearance
intended for another aircraft. As an example, assume that a controller issues an approach
clearance to an aircraft at the bottom of a holding stack and an aircraft with a similar call sign (at
the top of the stack) acknowledges the clearance with the last two or three numbers of his call
sign. If the aircraft at the bottom of the stack did not hear the clearance and failed to intervene,
flight safety would be affected when the aircraft at higher altitude descends into the lower
aircraft. This kind of "human error" can strike swiftly and is extremely difficult to rectify. You
must be certain that aircraft identification is complete and clear before taking action on an ATC
Unlike ground station call signs, aircraft call signs normally will not be abbreviated.
Aircraft call signs may only be abbreviated when ground controllers initiate an abbreviation.
Controllers will not abbreviate call signs if potential confusion exists between similar sounding
call signs. Once the controlling agency has abbreviated your call sign, it is permissible to use the
same abbreviation when responding to that same controlling individual.
"Houston Center, KATT 811, 10,000."
"811 roger, climb and maintain 12,000."
"811 leaving 10,000 for 12,000"
At NAS Pensacola, similar call signs exist using prefixes such as KATT (VT-10), BUCK
(VT4) and ROCKET (VT-86). Many times a controller will tell you that an aircraft with a
similar call sign is on your frequency:
"KATT 804, be advised KATT 814 is on the same
1. The 24-hour clock system is used in radio transmissions. The first two numbers indicate
the hour and the last two numbers indicate the minutes. FAA uses Greenwich Mean Time (GMT
or Z) for all operations.
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TECHNIQUE AND TERMINOLOGY