Lets look at a particular aeroplane, one which was designed from the outset as a CATIIIC machine, without compromises.
Of course, I referring to the first wide-body to qualify, the superb Lockheed TriStar.
Looking further, lets look at some possible malfunctions.
The TriStar was designed to be fail operational in all respects, and where this, because of some system abnormality, was not possible for whatever reason, then fail passive.
So, on final approach during an automatic approach/land maneuver, the runway alignment maneuver begins at 150 feet agl.
This is possible because the rudder has changed to parallel operation when approach land track was established, earlier on.
IF, for whatever reason, the automatic runway alignment maneuver did not initiate, the pilot simply applies whatever rudder is needed...manually.
Just depress the appropriate rudder pedal, nothing else.
The automatic approach/land maneuver continues as otherwise normal.
Another example.
Suppose, for the sake of discussion, that the 'flare' maneuver did not initiate.
All the pilot has to do is apply sufficient backpressure on the pole, and the aeroplane will roll right on...smoothly.
Now, I have been flying the L1011 for
many years, yet I have never seen any of these modes of failure.
Why not?
Because, when these old airplanes were assembled at Palmdale, the quality went in, before the name went on...absolutely, positively.
Ah.....Lockheed