In flight school, we are taught that pitch controls speed and thrust controls flight path angle. For example, if one is slightly below the GS, in order to get back on the GS, the theory is that one would first increase thrust in order to regain the vertical flight path. Then, this would require a compensatory increase in pitch in order to maintain the speed. Is this how it is done in airliners as well? Or are airliners flown with pitch for flight path and thrust for speed since their engines take longer to spool up? I recently talked to a real-life A330 pilot who told me that airliners are flown like Cessnas - IE pitch for speed and thrust for flight path.
Depends! Methinks your "real-life" A330 pilot must be a flight simmer because on final approach, where you will be most likely to handfly, he's wrong.
On final approach, control speed with thrust, and pitch with the control column. Jets are not Cessnas. Actually the correct way to fly a Cessna is the same; it's just that it seems "easier" to do the opposite ie pull the throttle off to go down more because of the lift effect of the propwash over the wings.
Just fly like the autopilot does on the ILS. If it gets below slope, it pulls the stick back to get back on the glideslope
then corrects with thrust
if it gets slow. If the speeds increases, the autothrottles pull back to slow back down. It doesn't pull the nose up,off the glideslope, to slow down! Think of the primary effects of controls. Then it will be obvious how to fly. We don't use the secondary effects of controls in jets because the reaction takes too long (unless you fly a 737...
).
If the airliners like the 777 are indeed flown like a GA plane (i.e. pitch for speed and thrust for flight path),
They aren't, depending on what you are actually doing...
I don't fly the 777 but my machine does a similar thing if only climbing a couple of thousand feet ie lower thrust than full climb thrust. However, I wouldn't use this particular unique scenario to generalise. For a prolonged climb, FLCH will set and hold climb thrust, and the pitch controls the speed. Similar for an Idle/FLCH descent; throttles put to Idle by the autothrottle and stay there (unless moved, but that is another story), pitch controls the speed.
For example, assume that one is flying in V/S mode at -1000 FPM, speed 250 knots. Assume that one wants to increase speed to 270 knots. In order to accomplish this, does the plane first pitch down to accelerate to 270 knots, and then increase its thrust to maintain the v/s at -1000? Or does the autopilot use thrust to accelerate to 270 knots and reduce pitch to maintain the -1000 FPM?
This applies to all aircraft: the thrust will be increased to increase the airspeed. The VS will be held by the AP at 1000fpm. A similar thing happens when the AP is following a VNAV path: it will use the throttles to control the speed because the pitch control is being used to stay on the path. I believe Boeings also have VNAV SPEED. Don't ask me how that works or why it exists... I never have been able to understand it.
"THR – autothrottle applies thrust to maintain the climb/descent rate required by the pitch mode ".
Sort of. For a short climb (as you described, where full power would result in too much VS and an overshoot of the altitude), yes. For a climb (or descent) in VS, yes. For a long climb, No (throttles set to max, speed controlled with pitch). For a descent in VNAV PATH (I understand), Yes. For a descent in FLCH, No (throttles at Idle, speed controlled with pitch). Note the terms Idle and Max: they are the "limits" Fly3 is referring to.
You're probably an FO in the right seat. Just remember the old adage when flying an approach: "Always remember and forever take heed, right hand for flightpath and and left hand for speed!"
what is the difference between ATHR on Airbus and AT on Boeing? I heard they worked quite differently.
I'm interested in the answer to that too.
Knuckleheads who flew onto carriers need not reply!
Now I'll get my hat and coat!