Altitude Reports


Where does the data come from for the altitude reports on the trip logs. On a few of my flights they sometimes show significant changes (i.e., 1 minute I’m at 10,000’ - the next at 11,000’, and then back to 10,000’ again) - which simply didn’t occur. Why the incorrect data?


We see this pretty often during climbs and descents. It appears that when an aircraft is assigned a new altitude, the primary radar site trackign the aircraft continues to report the correct altitude, but another radar site (sometimes thousands of miles away) will report once that the aircraft is immediately at the assigned altitude.


The altitudes reported in the track log are not necessarily the actual altitudes at which the aircraft is flying. On a recent flight from ORD to SAF I flew at FL445 (yes, 44500’) most of the way, but the track log says I was at FL430 most of the time. I have noted anomalies in other track logs before so I take them all with a grain of salt. Not FA’s fault but the FAA system reporting fault.


Remember, there’s a difference between flight levels and altitude. Flight levels are according to a fixed barometer setting, so the actual altitude above sea level is not necessarily the same as the flight level.

Also, out of curiosity, what type of plane were you flying? Many planes, including all the 737 variants, are not certified above FL410.


I fly a Falcon 2000EX which is certified to 47000’ and I was cleared into a block altitude of FL430 - FL450. Of course, everyone at and above FL180 is using the same barometric setting (29.92") so I was flying an indicated altitude of 44500’ for much of the trip to get above turbulence. I eventually climbed to FL450 but the track log on FA said I was at FL430. I would guess that had something to do with the block altitude clearance. My point was that the track log doesn’t necessarily show the actual aircraft altitude.