> Alex Perry writes: > > (c) Remember that it reports pressure altitude and not any other altitude. > Is this true? I thought it was slaved to the altimeter. If so, > please scratch the last part of my previous posting.
No. Your mode C hardware shares the static port with the altimeter, but uses independent pressure sensing components. Thus, if you have a static failure in flight, you must immediately notify ATC and disable mode C. On the other hand, if your altimeter mechanically fails, you can continue with mode C and periodically ask ATC what altitude they see you being at. One benefit of having the transponder on pressure alt, with the ATC computer applying the kollsman correction for non flight levels, is that the radar display now provides correct relative altitudes of the aircraft even when a pilot has the wrong altimeter setting (eg after a cross country flight). _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel