Originally Posted by
DaveReidUK
Interesting graphic.
The altitude spike where the aircraft dips below the runway surface(!) accompanied by a single, instantaneous 2000+ fpm ROC value is clearly an artifact (unless Newton got it all wrong), probably coinciding with rotation.
This altitude dip below 0 is connected to erroneous high AoA readings.
It can be found in the altitude graph of the FDR readout of the Lion Air accident flight.
Check page 14 of this document:
https://www.flightradar24.com/blog/w...ary-Report.pdf