Aviation Emergency Tools

Interactive training aids for emergency procedures — practice makes proficient

Emergency procedures reference →
MAYDAY Call Builder

Fill in the fields below to generate a correctly formatted emergency radio call. Complete as many fields as available — the call updates live.

Generated call
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Lost Communications Decision Tree

Follow this interactive flowchart based on ICAO 7110.65 and CAA Lost Comms procedures. Click YES or NO at each decision point.

Have you lost radio communications?

Not a Lost Comms Situation

If you can transmit and receive normally, continue as cleared. If experiencing partial comms, try alternate frequencies and confirm with ATC. Consider a SELCAL check or relay via another aircraft.

Step 1 — Are you in VMC (Visual Meteorological Conditions)?

VMC Lost Comms Procedure
  • 7600 Set transponder to 7600 immediately
  • Remain in VMC — do not enter cloud or IMC
  • Make at least 2 radio calls on last known frequency
  • Try 121.5 MHz Guard and other likely area frequencies
  • Proceed to the nearest suitable aerodrome
  • On approach: rock wings or flash lights to signal ATC
  • Land and contact ATC on the ground as soon as possible

Step 2 — Are you operating IFR (Instrument Flight Rules)?

VFR / Uncertain — Lost Comms in IMC
  • 7600 Set transponder to 7600
  • Try 121.5 MHz Guard and all alternate frequencies
  • Attempt relay through other aircraft on frequency
  • Proceed via your last known clearance route
  • Land at the nearest suitable aerodrome and contact ATC

Step 3 — IFR Lost Comms: ICAO Standard Procedure

IFR Lost Comms — Follow This Sequence
  • 7600 Set transponder to 7600 immediately
  • Attempt all available frequencies: last assigned, 121.5 MHz, 243.0 MHz, area control
  • Maintain last ATC clearance — route, level, and speed
  • If no route filed, proceed direct to destination
  • At destination: arrive at ETA from last ATC clearance
  • If an EAT was received: hold and descend via published approach at EAT
  • If no EAT received: commence approach at your ETA
  • Land within 30 minutes of ETA
  • Watch for light signals from the ATC tower on final approach
Squawk Code Knowledge Quiz

10 questions testing your knowledge of transponder squawk codes. Select the best answer for each question.

Question 1 of 10
Score: 0
Emergency & Guard Frequencies

Key frequencies for emergency communications. All pilots should monitor 121.5 MHz at all times when airborne where practicable.

Frequency Name / Use When to Use Notes
121.5 MHz International Distress / Guard All civil emergencies; radio failure; SAR The primary civil distress frequency. All civil aircraft should monitor continuously. Broadcast MAYDAY or PAN PAN here first.
243.0 MHz Military UHF Guard (NATO) Military aircraft emergencies; SAR coordination UHF equivalent of 121.5 MHz used by military and some SAR assets. Monitored by NATO air defence radar units.
123.45 MHz Air-to-Air (Pilot-to-Pilot) GA pilot-to-pilot coordination Informal uncontrolled frequency. Useful for relaying a distress message to another aircraft if no ATC contact. Not a primary emergency frequency.
123.5 MHz Glider & Parachute Operations Gliding clubs; parachute drop zones Common UK frequency for gliding operations and parachute drop zones. Always check local NOTAMs for specific frequencies.
156.8 MHz Maritime Distress — Channel 16 Overwater distress; maritime emergency VHF Marine Channel 16. Monitored by coastguard and vessels. Use for overwater emergencies if no aviation frequency response. Transmit MAYDAY in standard format.
406 MHz Modern ELT / PLB Beacon Crash, ditching, overdue aircraft — automatic activation Detected by COSPAS-SARSAT satellite network worldwide. Provides GPS-accurate position to SAR. All modern ELTs and PLBs operate here. Register your beacon with the national authority (e.g. UKSAR / FAA).
121.5 MHz Legacy ELT Beacon (older devices) Older analogue ELT automatic activation No longer monitored by satellites (ceased 2009). May still be received by overflying aircraft. Upgrade to 406 MHz devices for satellite detection.
Transponder Squawk Quick Reference

The five most important squawk codes every pilot must know — memorise these before your first solo.

Code Meaning When to Set Type
7700 General Emergency Any in-flight emergency — engine failure, fire, medical, structural, fuel, etc. Emergency
7600 Radio / Comms Failure Complete or partial loss of radio communications (NORDO) Comms Failure
7500 Unlawful Interference (Hijack) Aircraft subject to unlawful seizure — set covertly if possible without alerting hijacker Security
7000 VFR Conspicuity (UK / Europe) VFR flight not in receipt of an ATC service — standard conspicuity code Standard VFR
2000 Entering Controlled Airspace Entering CAS without an assigned code, or VFR not receiving ATC service in some regions CAS Entry
Disclaimer: This page is for training and educational purposes only. The emergency scenarios depicted are simulations. Always follow your approved aircraft Emergency Checklist, your operator’s SOPs, and ATC instructions in actual emergencies. AviationRef.com accepts no liability for outcomes in actual emergency situations.