Air Traffic Control Communications and Clearances
This domain covers the clearance process from delivery to approach: what a clearance contains, how to read it back, and how instructions differ from expectations. RTR(A) questions frequently hinge on whether a transmission is a clearance, an instruction, or merely information.
Core rules
- A full IFR clearance normally contains five items: clearance limit, route, level, frequency and SSR code.
- On first contact give: station called, your call sign, position, level and intentions. Keep it brief.
- Read back clearances and instructions that affect safety: route, altitude, heading, speed, frequency, squawk and runway instructions.
- “Cleared” authorises; “expect” does not. A conditional clearance (“behind the landing aircraft, line up and wait”) must be read back in full, including the condition.
- “Hold short” is read back as “holding short”; “line up and wait” is not a take-off clearance. Only the tower issues take-off clearance, and “cleared for take-off” must be read back.
- If a readback is wrong, ATC says “negative, I say again…” and you correct it.
Worked example
Clearance: “VT-ABC, cleared to Delhi via W15, FL290, squawk 4521, contact Delhi Control 125.9 passing 10,000 feet.” Readback: “Cleared to Delhi via W15, FL290, squawk 4521, contact Delhi Control 125.9 passing 10,000 feet, VT-ABC.” Reasoning: route, level and squawk are clearance items; the frequency is conditional on passing 10,000 ft and must be repeated with the condition.
Traps
Reading back only the level; treating “expect FL290” as cleared; omitting “holding short”; failing to read back a squawk; and acknowledging a conditional clearance with “Roger.”