Definition
A communication breakdown in which a pilot reads back an ATC clearance or instruction incorrectly, and the controller fails to catch the error and correct it. The mistake then becomes operational, with both parties believing the message was understood correctly.
Plain English
When a pilot repeats back a controller's instruction wrong, and the controller doesn't notice the mistake, both end up acting on the wrong information.
Context Anchor
You may encounter this term in radio communication, taxi instructions, altitude assignments, route clearances, and accident or incident discussions.
Derivation
The term combines two parts of the radio exchange: the 'readback' (the pilot repeating the clearance back) and the 'hearback' (the controller listening to confirm it was heard correctly). The 'problem' is that both steps can fail at the same time.
Why Pilots Care
Failure to catch the error can result in the pilot flying an incorrect clearance, leading to loss of separation or runway incursions.
Analogy
It is like repeating a street address to someone on the phone, getting one number wrong, and the other person saying “correct” without noticing the mistake.
Grounding Statement
Both the pilot and controller assume the message was received correctly, allowing the discrepancy to go unnoticed.
Intuition Check
Do not assume this is only the pilot’s mistake or only the controller’s mistake. The problem is the failed check between the pilot’s readback and the controller’s hearback.
Example Sentence 1
The instructor explained that a readback-hearback problem can occur when the frequency is busy and the controller is managing several aircraft at once.
Example Sentence 2
Busy frequencies increase the chance of a readback-hearback problem during complex clearance instructions.