flightaware.com/live/flight/SWA1 … R/tracklog
I was looking for a friend’s flight and found a couple of crazy ascents/descents in here. Is this accurate? Can a pilot tell me what was going on here?
What you see at 9:30 and 9:46 in the track log are gaps in the feed from the FAA. The track log fills in the gap with the assigned altitude, in this case 30000ft.
FAQ’s and the use of the seach function can better help you.
thanks for your reply. I actually DID go through the FAQ before asking and was uncertain what to search under. I then tracked a couple of more flights and figured out the pattern. 
No, it’s not accurate. When the FAA’s computer has a position but not an altitude, it substitutes the filed or last assigned altitude.