I posted some data errors here before, and the mods fixed them on the site, so I will post again. First, is the fact that for some reason ORD keeps getting Sun Air of Scandinavia flight plans listed. Look here for a few of what I mean.
flightaware.com/live/airport/KORD/enroute/ga
flightaware.com/live/flight/SUS102
flightaware.com/live/flight/SUS828
flightaware.com/live/flight/SUS888
Sun air doesn’t fly to ORD, and as such the flights never depart, even according to FlightAware. The second “issue” is with Air Bridge Cargo flights. The site currently lists them as unknown owner, and puts them as a GA flight on tracking pages. For example, flightaware.com/live/flight/ABW601
The third issue, is that there have been a ton of UA 732 flights listed lately. Clearly those aren’t right.
flightaware.com/live/flight/UAL1051
flightaware.com/live/flight/UAL1516
flightaware.com/live/flight/UAL1142
flightaware.com/live/flight/UAL1 … /KDEN/KORD
This site is excellent as it is, but fixing these would make it even better! 
In addition: not to mention that random flights show a low filed crz speed of anywhere between 382kts and 419kts. When checked with another site the flight plan shows a number which seems a bit more accurate 
flightaware.com/live/flight/DAL1641 (FA shows: FL360 @ 405kts, Other shows: FL360 @ 464kts)
flightaware.com/live/flight/DAL1692 (FA shows: FL340 @ 411kts, Other shows: FL340 @ 468kts)
flightaware.com/live/flight/DAL1868 (FA shows: FL360 @ 382kts, Other shows: FL360 @ 467kts)
These are all DL but I’ve seen some on AA as well.