On Mar 18, 7:00*am, Darryl Ramm wrote:

It is my impression that many piltos with built in loggers like the
Cambridge 302 do not understand that the flight recorder is using
cockpit ambient pressure and not the static line-in on the rear of the
instrument (only used for airspeed calculations). This is a
requirement to prevent the pilot being able to connect to the static
line and tamperer with logged pressure altitude.

I'm aware of that but I see now that what I wrote may be ambiguous.
Perhaps this would have been better:

"loggers (which cannot have an external static connection) will read
lower than
an altimeter which has an external static connection. "


Andy