Originally Posted by
Jimmy.
In the picture of the aircraft's cockpit is possible to see both Flight Directors' Mode Select Panels (I don't remember the nomenclature on the 76) and AL 300 displays on the front panel, instead of in the center console. So, I don't think a passenger could have decoupled without pilot notice, considering the other way to do so is pressing a button on the cyclic.
Well, the obvious way to decouple is via the autopilot ("helipilot") control panel on the center console, just ahead of the seats. (I haven't found where the decouple button is on the cyclic control, except "at the bottom". I don't know how easily that can happen.) I believe that would've put the FD in SBY (?), so it'd have been somewhat noticeable, but there wouldn't be a chime or a caution light. But it still feels very unlikely for a passenger to do that when it requires a conscious action (and we don't even know if there was a passenger up front).
The big question is, how do you miss a rapid descent of over 1000 feet in 20 seconds?
Possible answers:
-- pilot looking outside (for traffic? terrain?)
-- pilot working with iPad (thought FD was coupled when it wasn't?)
-- pilot incapacitated
-- ...?
Where is the point when you say to yourself, "no use looking outside any more, time to go on instruments"? And not having flight following means you need to look out for traffic, right?