Air Traffic Control, Communications and Clearances
Air traffic control, communications and clearances are about authorisation and readback. The exam tests when a clearance is required, what must be read back, emergency procedures and standard phraseology.
Clearances and readback
A clearance is required in Classes A, C and D; in Class E, IFR requires a clearance. A clearance is an authorisation, not a guarantee of separation from all traffic. Read back runway, altitude, heading, frequency, transponder and hold-short instructions, and the aircraft callsign. Use standard phraseology: 'line up and wait', 'cleared for take-off', 'cleared to land', 'hold short'. 'Roger' means the message was received; it is not a clearance.
Emergencies and lost communications
MAYDAY is for distress; PAN PAN is for urgency. SSR codes: 7700 emergency, 7600 radio failure, 7500 unlawful interference. On radio failure, squawk 7600, maintain the last clearance, remain VFR if possible, land as soon as practicable and notify ATC. The pilot in command may deviate from a clearance to meet an emergency but must notify ATC.
Worked example
ATC says: 'ZK-ABC, cleared to land runway 23, wind 240 at 10.' The pilot reads back callsign, runway and any hold-short or altitude instruction. If not ready, the pilot says 'unable' rather than accepting the clearance.
Traps
- Treating 'Roger' as a clearance.
- Reading back only the callsign.
- Confusing 7600 with the emergency code.
- Thinking VFR in Class D needs no clearance.
- Treating 'line up and wait' as a take-off clearance.