Are there maneuvering limits imposed on the 135 once the mains are down to 0kg and both XFER pumps are selected to off? If you nose her over a bit too enthusiastically would some of the fuel in the supply tanks spill over the wall and back into the main tank?
As for the reported "tumbling" (nose over tail) by one eye witness can we discount that once and for all as it would be a difficult maneuver to achieve even with a perfectly controllable helicopter (ok, I've seen a solitary backflip at an airshow but that needed plenty of skillful purposed flying to achieve), and bits of helicopter would start departing after the first few uncontrolled "tumbles".
My take on this is that there must have been some kind of major conflict between the fuel status display on the computer screen and the captions/gongs that were going off. I'm sure this experienced pilot knew there was enough fuel remaining to comfortably get back to base so perhaps figured that with 2 out of 3 in his favour he had time to troubleshoot the fuel problem. Is there a chance he could have turned the XFER pumps on then off several times in his battle to get at that remaining fuel to silence those captions/gongs only to be greeted with even more erroneous and confusing behaviour by the fuel status displays, or they had frozen indicating useable quantaties from several minutes ago, until it was all too late.
As I have said before I feel he did enter into an autorotation successfully, but all autorotations carry significant difficulty and risk, even more so at night.
Last edited by cattletruck; 18th Feb 2014 at 07:15.
Reason: added more about my distrust of computers