Altitude accuracy

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Altitude accuracy

Author	Message
Colin9	C Colin9 posted 9/19/2020 4:58:51 PM Topic Details Share Topic
C Group: Forum Members Posts: 2, Visits: 0	Always use Skydemon during aeros to confirm compliance. After last flight had a look to see two altitude busts with a max at 6734ft having started at 5000ft and a dive to zero ft and back. Plan view was very accurate. Downloaded a virtual radar of the exercise which confirmed nothing over 5500ft and the vertical profile matched the exercise. Any clues as to how the altitude is measured and why the error should be so large? Thanks, Colin
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Tim Dawson	Tim Dawson posted 9/21/2020 9:24:37 AM Post Details Share Post
Group: Forum Members Posts: 8K, Visits: 9.1K	It's somewhat beyond the remit of our support in these forums to describe the limitations of GPS altitude, but there are many, and it would be a good idea to read about them. Your altimeter should always be your primary source of altitude data while flying.
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Colin9	C Colin9 posted 9/21/2020 7:13:27 PM Post Details Share Post
C Group: Forum Members Posts: 2, Visits: 0	+x Colin9 - 9/19/2020 4:58:51 PM Always use Skydemon during aeros to confirm compliance. After last flight had a look to see two altitude busts with a max at 6734ft having started at 5000ft and a dive to zero ft and back. Plan view was very accurate. Downloaded a virtual radar of the exercise which confirmed nothing over 5500ft and the vertical profile matched the exercise. Any clues as to how the altitude is measured and why the error should be so large? Thanks, Colin Tim, I agree with your wise words, this is just my backup if confronted. But to find an error of this magnitude (1200ft) is disturbing but it may have been a bad day for GPS. Repeated the exercise today and all was well. to 200ft including the transponder. Colin.
	Reply Like 2
Tim Dawson	Tim Dawson posted 9/22/2020 9:43:48 AM Post Details Share Post
Group: Forum Members Posts: 8K, Visits: 9.1K	It's worth noting that GPS altitude inaccuracy is magnified during aerobatics as line-of-sight to the satellites is repeatedly blocked by different bits of the aircraft. I would be very surprised if GPS altitude was NOT wrong during aerobatics, perhaps significantly so.
	Reply Like 2