Human factors and communication errors
This section covers human factors and communication errors: why trained pilots still mishear clearances, how workload and expectation affect communication, and how readback and challenge reduce error.
Core rules
- Communication is a loop: transmit, receive, read back, and have the readback checked. A clearance is not complete until the readback has been heard and accepted.
- Expectation bias makes pilots hear what they expect rather than what was said. If a clearance does not sound right, ask “say again” or “confirm”.
- Fatigue, high workload, distraction and noise increase error. Keep non-essential conversation out of critical phases of flight and use a sterile cockpit discipline.
- Standard phraseology reduces ambiguity; slang and improvisation increase it. Speak slowly and use standard words.
- If you realise you have misread a clearance, correct it immediately with “correction” and the correct readback.
Worked example
A controller transmits “climb two thousand”. The pilot, expecting four thousand, reads back “climb four thousand”. The controller hears the wrong readback and replies “negative, climb two thousand”. The pilot corrects the readback. The error was caught because the readback was monitored; without that check, the aircraft could climb to the wrong level.
Traps
Assuming a clearance without reading it back; not asking for repetition when unsure; using non-standard phrases; and allowing distraction to break the communication loop.