Something to remember if you suspect that a pilot is down/lost might be
to solicit help monitoring 121.5 from commercial traffic in the area via
a request through ATC for a geographic area. Just a thought.

Nolaminar wrote:
The only time that 121.5 is monitored is over the ocean or very remote areas.
While I can't speak for ALL Carriers, I am pretty sure that none listen in on
121.5 while over the continental US.
Bob Gaines
Retired
Delta