what ever ever happened to the basic idea (I learnt it in 1974 FFS) POWER/THRUST PLUS SENSIBLE ATTITUDE EQUALS PERFORMANCE.Why has this basic law of physics been unlearned?
the flight directors should follow *you*.
Amen to both. I spent years beating into my students the basic FD philosophy: "if it's correct and helping then follow it, if it's not then reprogram it or turn it off."
No.1. How do you know it's correct? In the days before FD's the same computer was between your ears. You interrogated the 'T' and decided if the a/c was doing what you wanted it to. If it was, you left well alone; if not you adjusted whichever parameter needed adjusting and kept scanning the T. Now, in theory, the FD does this for you. But back to the basics; you need to scan the T (less intensely than before)to confirm the FD is correct & sensible. You must not be an FD slave. The best computer is still between your ears.
No.2. B737NG the FD needs to detect an error between CMD input and actual performance. It will then give guidance, in a direction, to correct the error. It will not give a fixed amount of correction. If you let the error progress the FD deviation will increase. Just look at the guys who rotate too slowly or at too high speed. The FD goes very high >18, way above 15, and see what happens to the speed as they follow it. It then pitches down to 15, or even less. If you are smooth and go 'towards' the FD e.g. 16 it will then descend to meet you. Job done smoothly. Same in LNAV SID's. If the turns are severe & you lead the FD for turns by a gnat's cock it will be smooth and not overshoot at all. Ah, but then you need to scan the MAP; heavens above, there's a MAP?
No3. Same on ILS. Scan the raw data LOC/G.S. and you can smooth out the FD PIO and anticipate what it's going to command you. You can correct the error BEFORE it has occurred.
I did stalls with FD's ON & OFF in ALT HLD. At the stall I froze the sim and asked the students what the FD was showing in guidance? Nothing, because it was centred. Ah, but you are about to stall, so is it useful? What is the ATT? Now repeat with F.D's OFF. Ah Ha!
I've always advocated, but never been given the time, that students should learn to fly the basic a/c. Then add the FD, then add the automatics, then add the non-normals. Nowadays the only non FD flying they get is the tick in the box level turns and the tick in the box raw data ILS. That's it. No wonder they don't know what it should be doing with AFDS in use, and thus they can not monitor it. With A/P engaged the FD's will inevitably be centred, but are they correct? Cadets monitor the A/P via the FD's and if they are centred then everything's alright.....as they stall in ALT HLD. Ah Ha! If you want to monitor A/P performance it would be easier with FD's OFF; then you would have to monitor exactly what the a/c was doing.
The future is not what it was and is getting harder to predict. But will standards improve to what they were? It will be for others to find out and attempt to stop the rot.