This is a detailed question - but then again that is the nature of accuracy issues. Take for example Flight N2076S of a Cessna 210 from KGEG (Spokane, Washington) to Nampa, Idaho (S67) on 4 Dec 2009.
a) The track log shows an impossible rate of climb of 2940 fpm 3 data points from the end of the file. (5:54 pm)
b) When I use Google Earth to plot the path it shows the path terminating at an altitude of 10,600 ft (runway altitude is approx 2500 ft) when less than a mile from the threshold of Runway 29.
c) When I try to line up the Lat / Long on Google Earth with the track log they are off by over 0.2. For example the flight terminates at 43.57 according to the log. But the Google track shows it terminating at 43.34. This is a difference of over 25 miles!
Any help would be appreciated on what I can reasonably expect with respect to accuracy.
The FAA sometimes sends us some bogus positions after the end of a flight, often with the altitude set to the filed cruise altitude. The tracklog detects and suppresses them, but the raw track is in the Google Earth file.
Thanks for taking the time to respond but if you could please take some additional time and re-read my original post you will find that the impossible number is in the track log in the first case i.e. rate of climb. As for the altitude, Google Earth and the raw FAA track data would have us believe we’re over 10,000 ft only a mile back from the runway - however if the real position at that altitude should be 25 miles back (as per the track log) maybe that makes more sense.
Which raises another question - at which point of the flight do you usually start receiving data and at which point do you stop receiving data. It seems to vary quite a lot - especially if in this case it terminates 25 miles back from the landing spot.
Any insight you could provide would be appreciated.
P.S. Does anybody know any system out there that tracks how far down the runway the aircraft actually touched down?
If my arithmetic is correct, based on the reply from mduell, it shows you climbing 5900 feet in 2 minutes, which is about 2,950 fpm. Your tracklog shows 2940 fpm. A lot of times the ASDI feed from the FAA shows your filed cruise altitude AFTER you touch down as a mistake. This seems to happen mostly at uncontrolled fields (unverified, personal experience)
2940 fpm is not an “impossible” climb rate, so I don’t think there would be a way to “smooth” this error.
For instance, if you did a missed approach, at an uncontrolled airport, in a jet, before canceling IFR with ATC, and your missed approach altitude was 5900 feet AGL, you would probably be climbing at about that rate, or more.
When did you cancel your IFR flight plan on that leg, that may shed some light on this specific flight?
The FAA sometimes sends us some bogus positions after the end of a flight, often with the altitude set to the filed cruise altitude. The tracklog detects and suppresses them
I have seen this many times on my flights. I see them mainly at my airport which is uncontrolled and I cancell IFR in the air. My altitudes will show a constant descent and then after I cancel, just like your log you point out, the altitude jumps to my last assigned altitude or my filed cruise altitude for the last couple of entries. This is not a flaw within Flight Aware as this happens at other flight tracker websites. The only time I see my altitudes properly reflected is when I hold my clearance when conditions are IMC and I cancel via RCO
In my experiences, starting data begins when you pick up your IFR clearance AND the wheels have left the ground for both controlled and uncontrolled airports.
At controlled airports, when ATC marks you arrived, that’s when the data stops. At uncontrolled airports it’s when you cancel your IFR in the air AND ATC marks you arrived. I have seen at BHM that I get marked arrived when handed off to BHM approach from Atlanta Center. This leaves a 25 mile gap in my track line from the handoff to the airport even though I never canceled IFR flying into KEKY.
My experiences have been once I have been handled over to tower the tracking stops and I never see the last logged altitude at field elevation so I don’t think it ever tracks you while you are on the ground.
