Originally Posted by
hoss183
They don't all occur out of ADS-B coverage.
I stand corrected - it looks like the succession of 307 kts values were while out of coverage (05:02-06:33), and the subsequent 84 kts readings when back within range (07:02-08:40).
The 7700 squawks didn't start until about 10:20, so I still can't see any obvious connection between the emergency and the dodgy ADS-B data.