# Speeds

**URL:** <https://discussions.flightaware.com/t/speeds/11076>\
**Category:** General\
**Created:** [December 18, 2010, 9:18pm UTC](https://discussions.flightaware.com/t/speeds/11076 "2010-12-18T21:18:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![chiz](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/chiz/32/12787_2.png) [@chiz](https://discussions.flightaware.com/u/chiz)\
**Post date:** [December 18, 2010, 9:18pm UTC](https://discussions.flightaware.com/t/speeds/11076/1 "2010-12-18T21:18:10Z")

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How does Flightaware derive listed speeds as filed and as observed.True Airspeed? Groundspeed? Is this an average?

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**Author:** ![mduell](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/mduell/32/115680_2.png) [@mduell](https://discussions.flightaware.com/u/mduell)\
**Post date:** [December 18, 2010, 10:05pm UTC](https://discussions.flightaware.com/t/speeds/11076/2 "2010-12-18T22:05:36Z")

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Filed is airspeed filed by the pilot/dispatch.

Actual is groundspeed observed by FAA radar.