An uncomfy Q for the aviators here

"Ramapriya" wrote
You're the First Officer. You notice the Cap'n deviating on something
from the airline's SOP, and it's more important than something like the
taxi speed limit. What do you do?
Presume that there isn't a procedure in the SOP on how to handle
deviations of the Cap'n (kidding)

Ramapriya.... probably the wrong newsgroup since very few of the readers
of this group have trained as, or served as a second-in-command in an
aircarrier's "cockpit resource management" (CRM) program.

When I first joined PanAm in 1967, one did not dare correct one of the
old WWII Clipper "gods". Actually, the flight engineer might get away with
it better than the copilot because he belonged to a different union.
Because of this cockpit atmosphere, we crashed 13 of our 130 B-707s.
Then, after an analysis, the FAA demanded a week-long CRM course for all
flightcrew members and revisions to the operating manuals to require that
ANY deviation from SOP be called to the attention of the pilot flying.
With this now being taught in the simulator sessions, the "captains" began
to accept it as normal procedure during line flying. Of course, by this
time, most of the "gods" were retireing and the upgrading copilots who had
suffered for years without CRM turned out to be much more understanding
and accepting pilots-in-command.

At least one very experienced pilot has told me that such a scenario
isn't as highly improbable as I'd first imagined

Read some of the following incidents pertaining to CRM issues.

http://asrs.arc.nasa.gov/report_sets/crm.pdf

Bob Moore