"John R Weiss" wrote in message
news:_LWOb.84380$Rc4.305921@attbi_s54...
"Ron Natalie" wrote...

Squawk 7700 briefly (15 seconds?) to get the attention of ATC, and
to
give
some notice of your intention to exercise your PIC emergency authority
to
"bend"
the regulations.

Not necessary. If squawking anything is working, 7600 will get their
attention just
find. You don't need to give them any such notification.

I don't know the current state of the art of ATC radars. However, the
7700/7600
switch was a part of the Navy Instrument Flight Manual as late as 1994.
The
rationale was that not all ATC radars had the same level of alerting for
7600
squawks as 7700, and/or that the alert might be manually disabled.

If all ATC radars now have the same level of alert for a 7600 squawk, then
7600
only makes sense.

7700 for one minute, followed by 7600, is one of the "wrong" answers in two
questions on the IFR knowledge test, and I always assumed that was because
it is a known incorrect or obsolete practice. However, one of the questions
specifies "you do not exercise emergency authority", so isn't exactly
appropriate to the specified scenario.

-- David Brooks