Ron Swanson said:
GTC58 said:
The B777 has a super critical wing, as such it is not really designed to have aerodynamic inherent stability. Without pilot inputs it doesn't take very long for the aircraft to depart its altitude and flight path in manual flight.
This is not true at all. The B777 is a fly by wire aircraft, the aircraft is flow by the primary flight computers (PFC) which interpret pilot inputs to the flying controls and the current flying conditions (speed, alt, configuration) and move the control surfaces as appropriate. If there is any inherent instability of the wing design it is irrelevant.
If the the auto pilot is switched off and the pilot makes no input on the flying controls the aircraft will continue to fly on roughly the same path as it was before the A/P disconnected.
So true. The wings are attached in the lateral axis (roll) with plenty of dihedral, which more or less will force wings level in the absence of control inputs. Along the longitudinal axis (pitch) the wing is mounted to the wing box with a positive cant of a 5 or 6 degrees relative to the deck angle. With that in mind, a "suicidal" pilot holding the yoke fully forward, and trimmed fully AND (aircraft nose down) should run out of control authority before the wings depart the aircraft in a dive, allowing the nose to rise checking the descent until the airspeed drops. IMHO, keeping a 777 in a headlong vertical descent from cruise would be impossible (thankfully).
