"Is there something fundamentally different about airspeed control in large jet aircraft? My experience is that pitch controls airspeed and power controls climb/descent, especially in the approach to landing situation. "

It depends on what level of automation is being used and the automation modes that are active. For a coupled (autoplilot engaged) ILS approach on almost all large transport aircraft, pitch is used to null glideslope error and thrust is used to null speed error.

Similarly, in an altitude hold mode, pitch is used to null altitude error and thrust to control speed error.

However, there is another set of control modes in which speed is controlled by pitch and climb/descent rate is controlled by thrust (thrust typically being idle in descent and current thrust limit for climb)

That's a simplified picture and the modes, and the names of those modes, are not well standardized. In the end, no matter what mode you use, pitch and thrust combine to control performance.

On a hand flown ILS approach experienced pilots will argue about whether thrust controls path or speed. However you can't escape from the fact that they interact and, if you change one, you most likely also need to change the other.

Direct lift control has also been used for glidepath control and it has the advantage of eliminating the pitch/thrust coupling seen using the more conventional method.


Andy