Any thoughts on how the 'g' loadings in the turns might be calculated?
There appears to be no CAS data in FR24, only GS, (and no bank-angle, of course).
Problem is that the critical part of the the ADS-B track seems inexact and cut short.
The circle before, leading up to the speed going down to around stall speed is rather unsuspicious. It has a radius of ~700m at a (Ground)speed of 100-130kts with a slight descent. This would equal to a g- load of ~1.2g.
Towards the end of the circle it climbs ~300ft and (ground) speed decays from 130kts to 55kts which energywise (trading kinetic energy for potential energy) almost perfectly matches the altitude gain. This would indicate a pull up at low power/idle. Up to that point the trace looks reasonable and credible for a test flight.
After that I wouldn't put too much trust in the remaining part of the track. It does look like a stall being recovered and a subsequent high speed dive possibly with an initiated pull- up..
And now for some musings:
If we would take the figures as they come (with the usual ADS-B caveat):
The acceleration is on the high but possible side for a steep dive out of a stall: G/S increases within 6s from ~40kts to 140kts, Descent rate reaches 14kfpm. Along the trajectory this would equal to an average longitudinal acceleration of ~1g (speed ~200kts). Descent rate then decreases within ~3s from 14kfpm at G/S of 140kts (would correspond to a dive angle of 45°) to around 9kfpm at a G/S of 175kts (corresponding to dive angle of 27°). This pull- up would produce an average g load vertical to the flight path (I assumed 35° angle as reference point for normal gravity) of ~2.3g.That doesn't say anything about peak loads, though. So besides general inaccuracies and having only G/S instead of airspeed this neither contradicts nor confirms a possible overload and/or overspeed in the dive or pull- up. Speed and descent rate both appear high, though.