(1) Shadows. If no other means are available, you may have to construct mounds that will use the sun to cast shadows. These mounds should be constructed in one of the International Distress Patterns. To be effective, these shadow signals must be oriented to the sun to produce the best shadows. In areas close to the equator, a North—South line gives a shadow anytime except noon. Areas further north or south of the equator require the use of East—West line or some point of the compass in between to give the best result.
(2) Size. The letters should be large as possible for a pilot or crew to spot. Use the diagram below to incorporate the size to ratio for all letter symbols.
(3) Contrast. When constructing letter symbols, contrast the letter from the surrounding vegetation and terrain. Ideally, bring material from another location to build the letter. This could be clothing, air panels, space blanket, etc.
(a) On snow, pile pine bough or use a sea dye marker from an LPP (Life preserver, personal). Fluorescent sea dye markers have been sighted as far away as 10 miles, although the average detection distance is 3 miles.
4. AIR TO GROUND COMMUNICATIONS. Air to ground communications can be accomplished by standard aircraft acknowledgments.
a. Aircraft will indicate that ground signals have been seen and understood by:
(1) Rocking wings from side to side. This can be done during the day or in bright moonlight.
b. Aircraft will indicate that ground signals have been seen but not understood by:
(1) Making a complete, clockwise circle during the day or in bright moonlight.
Was this article helpful?