The 777 FCS is totally compensatory and has ultimate built-in redundancy with numerous fall-back, fail-safe and fault-defeating configurations. Even when the APU fuel supply line dries up and the RAT is deployed as sole power provider, the FCS is still true blue to its specs. That's what makes the fuel exhaustion death-dive shown in the risible 60 Minutes program so ludicrous - and the recently released Larry Vance book on MH370 so off-base. I could tell that Martin Dolan (ex-ATSB chief) was in squirm mode. He's left the theory at the links below still sitting for inspection on ATSB's website (where it was posted many years ago now). After the 2nd engine flamed out and a descent set in, the aircraft would have ditched in a fairly optimal wings-level clean attitude. The simulator flown by airlines is quite different in the reproduction of this FCS inherent stability characteristic- but Boeing's "iron bird" tech simulator faithfully reproduces the flight characteristics. That's why "BOEING KNOWS" and the FAA is now making sure that the oxygen hose fire "fix" is well and truly "in"..

One advantage of a very Sophisticated Flight Control System -> Its sensors are anticipatory:

Auto-pilot OFF, a 777's uncommanded wing-drop is wing-leveled within micro-seconds - which leads to a very stable auto-pilot OFF heading stability (except when severe turbulence intervenes -as in ITCZ conditions or orographic turbulence (such as standing waves off of Sumatran Mountain ranges) - and all inherent stability bets are then off due to convective or leeward terrain generated air-mass mix complexity). But upon regaining clear air, the ejectment heading is then maintained +/- around 5 degrees max for very long periods (i.e. longitudinally sinusoidal to a very very minor degree). Similarly, the pitch phugoid damping is excellent and highly responsive to mild disruptions. With no pax or crew movement, the fuel burn-off just allows a continuous stable climb-rate of a few FPM. As the airplane ended up on a Southerly heading after the last ejectment, it was climbing into quite smooth cloud-free air to the south of the seasonal ITCZ band, and increasingly with a greatly reduced chance of bumbling into a CuNim and having the new base course heading change at all - compared to unpiloted ITCZ flight). Boeing is very much aware of the threat due to pilot incapacitation following crew supplementary oxygen fire and its typical trademark of rapid fuselage burn-through (image link). NASA has had a dedicated section for many years (decades in fact) accumulating statistics on nasty oxygen fires. No need to ask why. Read the links. The main blurb (1st link below) satisfactorily explains all the other "mystery" facets of MH370 as well. Second link is just an Exec Summary (and never kept updated).

tinyurl.com/or9bzf2  and tinyurl.com/gqpnwcn

Discussion was becoming centred on the latest 15 May 2018 release of yet another electrically conductive oxygen hose Airworthiness Directive by the FAA. See it here