Originally Posted by GearDown&Locked
it is almost impossible to control such movements, and the end is pretty predictable
Not so, as long as the engines have a thrust line somewhat above or below the C of G (e.g. B747, DC-10, A300), then thrust variation will provide for a reasonable degree of pitch control. This was pretty much proven in the Sioux City DC-10 accident.
If the thrust line is at or close to the C of G (e.g. B727, MD-90, F28, many business jets), then little or no useful pitch variation occurs with thrust change. Thankfully, for the examples that I've given, Manual Reversion, or Primary Manual control is available in all cases.
Regards,
Old Smokey