Emergency phraseology[PDF]

Minimum fuel

Pilot and ATC message exchange on fuel procedure:
  • Pilot: MINIMUM FUEL
  • ATC: ROGER [NO DELAY EXPECTED or EXPECT (delay information)].

Degradation of aircraft

Pilot in some cases should advise ATC of the degradation of his aircraft when performing procedures or manoeuvres:
  • NAVIGATION PERFORMANCE UNABLE RNP (specify type) (or RNAV) [DUE TO (reason, e.g. LOSS OF RAIM or RAIM ALERT)]
  • BASIC GNSS (or SBAS, or GBAS) UNAVAILABLE FOR (specify operation) [FROM (time) TO (time) (or UNTIL FURTHER NOTICE)]
  • BASIC GNSS UNAVAILABLE [DUE TO (reason, e.g. LOSS OF RAIM or RAIM ALERT)]
  • NAVIGATION PERFORMANCE UNABLE (navigation aid type)


Emergency descent

Pilot shall warn ATC when performing an emergency descent (mandatory):
  • EMERGENCY DESCENT (intentions)
ATC shall broadcast information on air when one or several aircraft are involved with this emergency descent:
  • ATTENTION ALL AIRCRAFT IN THE VICINITY OF [or AT] (significant point or location) EMERGENCY DESCENT IN PROGRESS FROM (level) (followed as necessary by specific instructions, clearances, traffic information, etc.)


Loss of communication (limited use at IVAO)

ATC instruction to instruct an aircraft before losing this aircraft on frequency :
  • [IF] RADIO CONTACT LOST (instructions)
  • IF NO TRANSMISSIONS RECEIVED FOR (number) MINUTES (or SECONDS) (instructions)
  • REPLY NOT RECEIVED (instructions)
ATC instruction when ATC suspect a loss of communication from an aircraft; he may test the communication link with the solution given below:
  • IF YOU READ [manoeuvre instructions or SQUAWK (code or IDENT)]
  • (manoeuvre, SQUAWK or IDENT) OBSERVED. POSITION (position of aircraft). [(instructions)]

See also

Reference

  • ICAO Documentation 4444 - Air Traffic Management - 16th Edition 2016 - Chapter 12

Author

  • VID 150259 - Creation & Wiki integration

DATE OF SUBMISSION

  • 22:00, 13 June 2021

COPYRIGHT

  • This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.

DISCLAIMER

  • The content of this documentation is intended for aviation simulation only and must not be used for real aviation operations.