Interception of civil aircraft
Free lesson · Air Regulations · DGCA CPL and ATPL
A military aircraft pulls up alongside. What each of its signals means, what you reply, and how you are warned off.
How do interceptor and intercepted aircraft talk?
Interception
Phrases are spoken twice when there is no common language.
- CALL SIGN KOL SA-IN What is your call sign?
- FOLLOW FOL-LO Follow me.
- DESCEND DEE-SEND Descend for landing.
- YOU LAND YOU LAAND Land at this aerodrome.
- PROCEED PRO-SEED You may proceed.
- WILCO VILL-KO Understood, will comply.
- CAN NOT KANN NOTT Unable to comply.
- REPEAT REE-PEET Repeat your instruction.
- AM LOST AM LOSST Position unknown.
- MAYDAY MAYDAY I am in distress.
- HIJACK HI-JACK I have been hijacked. Circumstances may not always permit its use.
- LAND LAAND (place) I would like to land at (name the place).
- DESCEND DEE-SEND I require descent.
- Series 4 · gear up, lights flashing over the runway Intercepted aircraft: raise the gear and flash landing lights passing over the runway between 1000 and 2000 ft (helicopters 170-330 ft), and keep circling. Means: this aerodrome is not adequate.
- Series 5 · regular on-off lights cannot comply Turning all your lights on and off at a steady rhythm (not the same as flashing). It means: I cannot do what you ask. The interceptor replies with Series 2: understood.
- Series 6 · irregular flashing in distress Irregular flashing of all available lights. Means: in distress. The interceptor answers with Series 2: understood.
Memory hook: Conflict? Do what the interceptor shows.
Takeaway: Call on 121.5 (repeat on 243), squawk 7700, set ADS-B/C emergency. If radio and visual orders conflict, obey the interceptor while asking ATC.
How are you warned off, and how do you acknowledge?
Warnings
Ground warnings, distress and urgency, and how to say 'understood'.
| Signal | How it is shown | Meaning |
|---|---|---|
| Restricted area warning | Projectiles every 10 s, bursting red and green | You are in, or heading into, a restricted, prohibited or danger area |
| Acknowledge in flight | Day: rock the wings · Night: landing (or nav) lights on and off twice | Understood |
| Acknowledge on ground | Day: move ailerons or rudder · Night: lights on and off twice | Understood |
| Distress | SOS · MAYDAY · data link MAYDAY · red rockets one at a time · red parachute flare | Grave and imminent danger; immediate help needed |
| Urgency: must land | Landing lights on and off repeatedly · nav lights switched, not flashing | Difficulties compel a landing; no immediate help needed |
| Urgency: message | XXX · PAN PAN · data link PAN PAN | Very urgent message about the safety of a ship, aircraft, vehicle or person |
Memory hook: Rock by day, flash twice by night.
Takeaway: Red and green projectiles every 10 s: leave the area. Acknowledge by rocking wings by day, flashing lights twice at night.