Enter Your LUNAR Details
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● RECMAYDAY LUNAR MESSAGE
Fill the form — your radio-ready MAYDAY message will appear here.
⚡ Short version (one-liner)
—
⚡ Immediate actions
- Declare MAYDAY early — don't wait
- Activate PASS / emergency button
- Control breathing, stay low
- Find wall or doorway, maintain orientation
📻 Radio
- Transmit LUNAR clearly, repeat if unacknowledged
- Report entanglement / collapse / fall
- Update air PSI and location if you move
- Follow IC / dispatch instructions
What Is MAYDAY LUNAR?
MAYDAY LUNAR is a structured radio communication format used by firefighters to transmit an emergency distress message. LUNAR stands for Location (floor, side, landmark), Unit (apparatus), Name (firefighter ID), Air/Assignment (remaining PSI and last task), and Resources needed. The format ensures critical information is communicated clearly and consistently under extreme stress.
When a firefighter is lost, trapped, or running out of air, panic causes fragmented transmissions. LUNAR solves this by giving every firefighter a memorized five-field script — covering everything Incident Command needs to initiate a rescue. You don't think, you fill in the blanks.
L
L — Location
Floor + building side (A/B/C/D) + specific landmark. The single most critical field — imprecise location delays rescue.
U
U — Unit
Your apparatus (Engine 7, Ladder 3, Rescue 1). Helps IC know how many personnel may be in danger.
N
N — Name / ID
Your name or radio designation. Confirms who is transmitting and cross-references the accountability board.
A
A — Air & Assignment
Remaining SCBA PSI and your last assigned task. Air estimates the rescue window; assignment narrows probable location.
R
R — Resources needed
What you need to get out — RIT, TIC, handline, ladder, extrication, EMS, spare air. Be specific.
LUNAR vs UCAN — What's the Difference?
Both LUNAR and UCAN are MAYDAY communication formats used in the U.S. fire service. The information they capture is similar — the main differences are structure and how Air status is handled.
| Field | LUNAR | UCAN |
|---|---|---|
| 1st | Location | Unit |
| 2nd | Unit | Conditions |
| 3rd | Name | Actions needed |
| 4th | Air + Assignment | Name (some versions) |
| 5th | Resources needed | — |
| Air PSI | Explicit field | Embedded in Conditions |
LUNAR is more common in the U.S.; UCAN is used in some regions and internationally. Always follow your department's SOP.
How to Give a MAYDAY Call
1
Declare MAYDAY three times
Key your radio: "MAYDAY, MAYDAY, MAYDAY" on the primary channel. Do not wait until you are out of air. Declare early.
2
Activate your PASS device
If not already activated, manually trigger your PASS device. It broadcasts your location to RIT.
3
Give your LUNAR
Location, Unit, Name, Air/Assignment, Resources — in order. Speak slowly. Repeat if unacknowledged.
4
Maintain position if possible
Stay low. Find a wall, window, or doorway. Avoid disorienting yourself further by wandering.
5
Update continuously
Report air level changes, new location, and new hazards. Keep the channel clear for IC instructions.
MAYDAY LUNAR FAQ
LUNAR stands for Location, Unit, Name, Air/Assignment, and Resources needed. It is the most widely used format for firefighter emergency radio communication in the U.S. fire service. The structure ensures critical information is transmitted clearly and consistently under extreme stress.
LUNAR: Location, Unit, Name, Air/Assignment, Resources. UCAN: Unit, Conditions, Actions needed, Name (varies by department). LUNAR includes an explicit Air (PSI) field and a dedicated Resources field. UCAN embeds conditions more broadly. Both formats are effective — always follow your department SOP.
Transmit 'MAYDAY, MAYDAY, MAYDAY' on the primary channel, then give your LUNAR: Location (floor/side/landmark), Unit, Name, Air PSI and Assignment, Resources needed. Repeat if IC does not acknowledge. Activate your PASS device. Control your breathing.
Floor + building side (A/B/C/D face) + a specific landmark. Example: '2nd floor, Bravo side hallway near the stairwell.' Avoid vague descriptions like 'somewhere inside.' Update your location over the radio if you move.
Some department SOPs define A as Air (remaining cylinder PSI); others define it as Assignment (last task). Combining both keeps the message useful across departments. Air helps IC estimate the rescue window; Assignment helps narrow your probable location.
Yes. Tap Share (or Copy Share Link on desktop) to generate a URL that loads the exact same scenario for your crew. No login required — opens instantly on any device. Ideal for tabletop and realistic radio drill exercises.
No. This is a training and communication aid only. In an actual MAYDAY, always follow your department SOP/SOG and dispatch procedures. The tool is designed to help firefighters memorize and practice the LUNAR format so it becomes automatic under stress.
Training reference only. Follow your department SOP/SOG in all real emergencies.
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