PPLRTO Extra Course Material
AC91-9 & AC172-1 Radiotelephony Manual
Required information about SSR Transponders: The ground-based radar antenna rotates (usually at 5-12 RPM) and transmits a pulse which is received by the onboard equipment. The transponder sends back a reply containing at least a code (if operating in Mode A) but more often this is combined with altitude information (Mode C) or other information, e.g. aircraft identification, etc. (Mode S).
AC43-11 Regarding AELS (ELTs)
GEN 3.6-10 Ground-Air Visual Signal Code
Volume 1 Pages Regarding UNICOM, AFRU, ATIS and AWIB
