I find when I am fixed on to LOC and waiting for GS to engage, when the green curser comes close to my altitude my aircraft pitches quite sharply up to curser then dips down to catch the green dot up for the aircraft to follow the descend on APPR.
Is this normal? Does this really happen in real life flight ?
Or is it me doing something wrong.?
It mostly depends on the flaps settings you’re using, and the speed you engage the LOC. Utilizing trim is a great way to keep your plane in good shape, whether it’s at cruise, takeoff, landing, climb, or descent. Adjust the percentage so that the purple bar doesn’t appear anymore. If the purple bar is indicating towards the bottom of the trim tab like in the above picture, you want more positive trim but I’ll really make sure with that I said first. I always make sure to follow the correct speed, etc, and works perfectly!
It kind of depends on what ATC ask me to do as well, as generally I get requested to fly at 3000 altitude approach witch is normally well below GS level. Plus now we get asked to go a certain speed as well to maintain space between each aircraft.
So when the GS is dropping to my FL the plane pitches up to climb to curser rather that the aircraft catching GS on the way down.
I have looked at previous peoples comments about this pitch up on GS and tried to do as they/you have said but still not a smooth transition when GS engages
The issue is that when an aircraft is “locked” on the ILS, the reverse of the normal primary flight controls apply …ie pitch controls altitude and power controls speed (normally it is pitch that controls speed and power is altitude).
So the aircraft uses pitch to control the descent on the GS. Because the VS mode is initially set to 0 when you are level, maybe it tries to set a pitch initially to hold level before the VS drops for the descent, and then the nose lowers again (thats why some extra power at that moment can help).
Of course in Approach mode we dont see an indication of what the actual VS is, but maybe it reduces from 0 after capture…
😄 And I don’t fly the Boeings because I can’t keep them straight on the runway at touchdown or rotation!
I often don’t use Approach mode anyway, and prefer to switch off AP and fly down manually, so I’m not usually too bothered. But I do think the matter should be looked into as the transition to GS capture should be smooth, assuming the aircraft is configured correctly and stable beforehand.
The reversal of the function of pitch and power when locked on the ILS applies to real aircraft and Infinite Flight. That aspect of the simulation is realistic, its just the transition onto the GS that seems to be an issue.
No way to avoid it, it’s a limitation of the autopilot logic. I would imagine the simplest coding solution would just be to delay the glide slope intercept until the GS is a bit closer, but who knows.
If you wan’t an actual answer, you can try not using approach mode. Switch the nav source to NAV1 and then LNAV alone will follow the localizer. Then, you can just disengage altitude hold just prior to GS intercept and manually pitch down to intercept.
I do catch the GS from below. And still aggressive pitch up to then pitch down to catch up GS again.
I’ve tried what other people say to do to stop this and watch the IF tutorials but this still happens. 🤷🏻♂️