Originally Posted by
tttoon
you will initially always need to pitch towards your desired flightpath, and then adjust thrust for speed.
You are advocating that if low and correcting up then you should lose speed first, and then increase it back to the target value. Why?!
The necessity of thrust to fix the vertical flight path is primary (in importance, though not necessarily sequence) as, again,
excess thrust dictates climb angle.
Had the pilots of Asiana 214 really grokked that, they might have come in with thrust as they sank further and further below the glideslope, instead of leaving it relegated to the back of their minds as some side effect to clean up later once the main problem had been solved (and then, in actuality, forgotten). No, they pulled more and more on the stick (ending up with dozens of pounds of pull force, IIRC) not realizing that by doing so they were commanding a decrease in airspeed. (As, again,
AOA dictates airspeed).
Back when I was teaching I remember flying with countless of other people’s students checking them out in new types (along with a few other factors such as that it’s tailwheel, minimal instrumentation, etc., that took them out of their comfort zone and loaded up their task capacity) and with regularity would watch their flight path fall off toward a point short of the runway, and then watch their response of pulling up their nose without power, which after the first few seconds’ initial (and temporary) success of pulling up the flight path, (and thereby tricking them into thinking the job was done) the induced drag at the lower speed would increase and the flight path would consequently fall off even further, then they’d respond with pulling the nose higher, feeding back into the same loop of higher AOA -> lower speed -> more induced drag -> more sinking tendency -> higher AOA. Each of these was a mini Asiana 214 in the making. And each of these could have been avoided with a thorough and early understanding of System 2 and that thrust is the primary control of vertical flight path.
Let’s consider the consequences of a stressed pilot initially forgetting one or the other (of thrust vs. pitch). If they forget thrust, the consequence is described in the above paragraph.
If they forget pitch, the consequence is much less severe. If the plane has a normal TPC, then the low plane would pitch up, beginning the glideslope correction with the same input. May be sloppy, but can be cleaned up later, and not dangerous. If it’s a reversed TPC, then the plane would start pitching down, which would surely catch the pilot’s attention and he’ll then pitch it up. Sloppy and slightly more dangerous than the normal TPC, but far less dangerous than if they forgot thrust. And it’s far less dangerous because
total energy is gained which increases the maneuvering ability, thus increasing their available time to react (whether this ability is used toward a re-stabilization, or toward a goaround).