Originally Posted by
riff_raff
Took a significant amount of axial force to tear all those planet gears off the carrier pins.
riff,
One might assume it took a similar magnitude of axial force to break 4 tabs on REDL as you can see in the photo below (Source AAIB Report 2-2011) but it is interesting that its gears stayed on and there seems to have been a limit to the axial displacement of the inner races – possibly contact with the 1st stage carrier?
Of course, the axial force component on LN-OJF may well have been much, much larger than that needed to just break these tabs.
I think the major difference was in whether the larger gear fragments went outwards between planet cluster and ring gear (G-REDL) or inwards between the cluster and the sun gear (LN-OJF). All consequential to the root cause – fatigue failure of a planet gear.
Last edited by Concentric; 10th Mar 2017 at 16:01.
Reason: typo