Phugoid Motion
I'll probably get deleted again, but still wondering after days why no one seems to have mentioned Phugoid, up & down motion lack of control, to explain staying in the air for hours without reaching an airport, and now, confirmation of extreme changes in altitude.
Damage to the a/c that led to lack of control leading to phugoid motion, eg. Engine Thrust only control, would allow the plane to fly around for hours with very little control over direction.
Phugoid - Wikipedia, the free encyclopedia
Examples are:
1985- Japan Airlines Flight 123
1989- United Airlines Flight 232
I'm interested to know what role the 777s envelope protection would play in a disconnected A/P ghost flight?