Documentation
Onboarding
Getting Started
Power & Battery
Hardware & Components
Build & Assembly
Radio & RF Design
Frequencies & Regulations
Firmware & Software
USB & Connectivity
GPS & Navigation
Morse & Communication
Modes & Operation
Field Operations & Rescue
Building Effectively
Build Variants
Project & Reference
Docs Field Operations & Rescue Mirror Signaling

Mirror Signaling

Edit on GitHub

Aiming a signal mirror at an aircraft or distant searcher, the sighting technique, and why a mirror beats a beacon in clear daylight.

Mirror Signaling

On a clear day, a signal mirror is the longest-range tool in the kit: flashes visible up to 15 km or more, far beyond the beacon’s radio range to a handheld. The skill is aiming, and aiming is a trick.

The aiming trick

Hold the mirror near your eye, sight through the hole or along its edge at the target (aircraft, searcher), and tilt the mirror until the bright spot falls on the target. The classic method:

  1. Put the target in the sight.
  2. Rotate the mirror until the sun spot appears in the sight.
  3. Small tilts move the spot onto the target.

Practice against a distant wall before you need it: the motion must be automatic.

Making the flash visible

  • A slow, rhythmic flash (2 - 3 seconds on, pause) is readable; frantic flashing is not.
  • Flash toward the target, not straight up.
  • Sweep the horizon in a slow arc when you do not know where the aircraft is.
  • The flash works on the shadow side of a ridge if the sun reaches you.

The three purposes

PurposeHow
Attract attentionSlow sweeping flashes
Signal distressThree flashes, pause, repeat (SOS rhythm)
Confirm positionSteady reflection toward the aircraft

In snow

Snow glare makes mirror flashes less visible: aim at the aircraft’s windshield, which reflects differently from the snow, and use a larger mirror. Do not flash directly at the pilot’s eyes; the flash toward the cockpit area is enough.