I85PREP
⌘ K
HK PPL Radiotelephony study materials
HK PPL Radiotelephony study resources

HK PPL Radiotelephony: Distress, Urgency and Communications Failure Procedures

HK PPL Radiotelephony · Work through your exam, one topic at a time.

All guide sections

Distress, Urgency and Communications Failure Procedures

This domain covers the calls you may have to make only once, and which must still be right: distress, urgency, radio failure, the associated transponder codes and the lost-communication procedure. Examiners test the difference between MAYDAY and PAN PAN, the content and order of the message, when 121.5 is used, and what you do when the radio goes quiet.

Distress and urgency

  • Distress (grave and imminent danger, immediate assistance needed): 'MAYDAY MAYDAY MAYDAY, Hong Kong Approach, B-HKA, Cessna 172, position 10 miles south of Cheung Chau, engine failure, maintaining 3,000 ft, intending to ditch, 2 persons on board, MAYDAY.'
  • Urgency (serious but no immediate danger, e.g. sick passenger, engine shut down but under control): 'PAN PAN PAN PAN PAN PAN', then the same content.
  • Relay a distress call you hear if no station answers: 'MAYDAY RELAY'.
  • Set 7700 for distress, 7600 for radio failure, 7500 for unlawful interference; read the squawk back if time allows, otherwise just set it.

Radio failure

Check headset and audio panel, try the last frequency and any standby, call on 121.5, squawk 7600 and try a relay through another aircraft. In VMC, continue under VFR, land at a suitable aerodrome and telephone ATC. In IMC, maintain the last assigned level and speed for 7 minutes after the last attempt, then climb to the minimum safe altitude and follow the published lost-communication procedure for the route. Transmit 'TRANSMITTING BLIND' on the frequency in use so others know your intentions.

Fuel and airborne conflict

  • 'MINIMUM FUEL' is an advisory: you expect no undue delay but claim no priority.
  • 'MAYDAY FUEL' is distress: you will land below final reserve.
  • A TCAS resolution advisory is flown immediately: 'TCAS RA', then 'CLEAR OF CONFLICT' when it ends.

Worked example

Oil pressure falls and the engine runs roughly 12 miles from Hong Kong. A forced landing is possible but not yet certain, so PAN PAN with position, level, nature ('rough running engine'), intention ('request diversion to the nearest aerodrome') and persons on board is correct. If the engine then fails, transmit a MAYDAY in the same format rather than continuing the urgency call.

Traps

Declaring MAYDAY for a delay; PAN PAN without a position; omitting persons on board, which search and rescue needs; calling on 121.5 while still in two-way contact with ATC; forgetting 7600 in a lost-comms scenario; treating MINIMUM FUEL as a distress call.