On Sep 20, 7:15*pm, Robert Gaines
wrote:
In other words, making an (emergency?) call on common

frequencies to establish contact with a private or commercial flight,
with the request to relay the information to your intended contact by
radio or phone.

Unless things have changed, commercial (Airliners) do not monitor 121.5.
*Bob

Do not? Like no airlines out there listening? Like no airline requires
or recommends this in their SOP? Like crews won't guard 121.5 even if
their company SOP does not require it? I suspect that just is not
correct and is certainly the wrong message to send.

I think the airlines are pretty individual about whether this is a
requirement or recommendation in their SOP or not. Some airline pilots
might want to speak up.

There is an ICAO requirement (in Annex 10, Part 5) for airlines to
guard 121.5. This at least is required on long overwater flights and
more ambiguously "where carriage of an ELT is required". What exactly
the later means is open to some interpretation. I think the net is
many intentional airlines will have guarding 121.5 in their SOP.

The bottom line is it's worth trying there is often people listening
on 121.5. Including lots of airlines whether it is their company SOP
or not.

---

And while on ELTs in the ICAO rule above, new 406MHz ELTs and PLBs
still also transmit a (low power) beacon on 121.5 so airliners and
others guarding that frequency for ELT as well as voice still makes
sense. But now hopefully as people refresh their ELTs with newer units
the false alarm rate will go down. And just a hint if your buddy is
flying with a Personal Locator Beacon (more common that ELTs in
gliders) and you think he may be down/in distress tune to 121.5 and
you should hear the distress "siren" sound, with the addition of a
morse code "P" (for PLB) dit dah dah dit. This only applies to USA
licensed PLBs, in other countries there is no Morse code "P".


Darryl