4−4−7. Pilot Responsibility upon Clearance Issuance
b. ATC Clearance/Instruction Readback.
Pilots of airborne aircraft should read back those parts of ATC clearances and instructions containing altitude assignments or vectors as a means of mutual verification.
Bear in mind the AIM is a collection of best practices and not regulatory, meaning, you are not required by law to read back any clearance. For regulation, we have to look to the Federal Aviation Regulations (FARs). What do we find there? Almost nothing on the requirement to read back a clearance. Just this:
§ 91.123 Compliance with ATC clearances and instructions.
(a) When an ATC clearance has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory.
(e) Unless otherwise authorized by ATC, no person operating an aircraft may operate that aircraft according to any clearance or instruction that has been issued to the pilot of another aircraft for radar air traffic control purposes.
Nothing from Something Does Not Equal Nothing
So why does Air Traffic Control expect a read back of these types of clearances?
“Cleared to land,” or, “Cleared direct to Ormand Beach [VOR],” or, “Cleared for takeoff.”
Maybe the Air Traffic Controller’s Manual, (FAA Order JO 7110,) has something to say on the subject. Let’s take a look:
2-4-3. PILOT ACKNOWLEDGMENT/READ BACK
a. When issuing clearances or instructions ensure acknowledgment by the pilot.
Pilots may acknowledge clearances, instructions, or other information by using “Wilco,” “Roger,” “Affirmative,” or other words or remarks.
AIM, Para 4-2-3, Contact Procedures.
b. If altitude, heading, or other items are read back by the pilot, ensure the read back is correct. If incorrect or incomplete, make corrections as appropriate.
The Controller’s Manual says a pilot should acknowledge clearances or instructions, but it does not direct what a pilot should specifically say in the read back. According to the manual, the words “Wilco,” “Roger,” or “Affirmative,” are acceptable responses to a clearance. The Manual also refers back to the AIM, which is not law, to reference the possibility that pilots might read back “altitude, heading, or other items,” but there is no specific legal requirement to do so.
How Many Ways Can They Dance Around the Subject?
After dancing all around this subject in the regs, it comes down to this. All the AIM recommends is “read back of the numbers.” If you want ATC to quality check your understanding of a clearance–which I believe is a very good idea–then read back all relevant information that affects the direction, speed, and altitude of your flight. This includes
- heading assignments;
- altitude assignments;
- speed assignments;
- runway assignments
- altimeter settings (because altimeter accuracy influences your aircraft’s altitude;)
- rate of climb or descent assignments;
- route changes, including holding pattern instructions;
- approach and landing clearances;
- takeoff and departure clearances;
- runway hold short instructions
- taxi instructions.
Why? It all goes back to the best practice stated in the AIM:
b. The single, most important thought in pilot- controller communications is understanding. It is essential, therefore, that pilots acknowledge each radio communication with ATC by using the appropriate aircraft call sign.
4-2-2 Radio Technique
c. Subsequent Contacts and Responses to Callup from a Ground Facility.
You should acknowledge all callups or clearances unless the controller or FSS specialist advises otherwise.
There you have it. Zero instruction from the FARs or the AIM on exactly what to say in your read back, but a strong recommendation to acknowledge instructions from ATC. Traditionally, air traffic controllers expect you to precisely read back any instruction that affects the flight path, (or ground path,) of your aircraft.
In my last article on this subject, I’m going to point out some examples of information pilots read back on the radio that have no bearing on their flight, and waste time on the radio. This will be an opinion piece, sure to stir up some controversy, so don’t miss it.