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lowew79

ILS and autopilot.

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This is more of a general aviation question than a J41 specific one, but where better to find good sim pilots than PMDG customers?

 

Ok, when I am flying ILS approaches (the last example was 35L at KDFW if that matters)  the localizer seems to take me left of the center line. Now I don't know if it is actually doing the right thing, and from the time I disengage the AP until touchdown I drift slightly left, or if the ILS course heading is different in real life than FSX, or if I'm waiting to long to disengage autopilot so I can't correct (should I have to though?).

 

Which leads to my first question.  At what point on a ILS approach should the auto pilot be disengaged?  200 feet above touchdown?  100?  as soon as runway is in sight?

 

Second question...  The speed cards in this aircraft are a fantastic feature.  However, I find myself constantly adjusting the power levers trying to hold at exactly that magenta line, almost obsessing over it.  So...

At what point in the approach should the speed go from the approach speed (magenta) to the Vref speed (Cyan)? over threshold?  100 feet above the runway?

Is it vital to hit those speeds exactly or is a few knots off acceptable?

 

I twist my joystick (x52) to try to add right rudder, but I seem to get no reaction at all from the aircraft.  Is landing on the centerline significantly harder without rudder pedals?  Should I be concerned with hitting it exactly?  Are there any tips for getting rudders to work without pedals?

 

I know practice makes perfect, and my landings are safe (at least FSPassengers doesn't seem to have a problem with them lol), just not as good as I'd like.  Thanks for any tips.

 

 

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At what point on a ILS approach should the auto pilot be disengaged?  200 feet above touchdown?  100?  as soon as runway is in sight?

 

As soon as you're ready to fly the plane. Ideally earlier rather than later - it'll give you time to adjust to the feel.

 

 

 


At what point in the approach should the speed go from the approach speed (magenta) to the Vref speed (Cyan)? over threshold?  100 feet above the runway?

 

This is in the manual (and I say that because I don't have it handy at the moment), but the general rule of thumb is VREF over the threshold.

 

 

 


Is it vital to hit those speeds exactly or is a few knots off acceptable?

 

It's good form to be on speed, but for VREF, only err on the high side (faster than VREF - never slower).

 

 

 


Should I be concerned with hitting it exactly?

 

Not if it compromises putting the plane on the ground safely. Landing off center can also avoid running the nose gear on the centerline lighting.

 

 

 


 Are there any tips for getting rudders to work without pedals?

 

Make sure you have the auto-rudder function turned off in your FSX settings.

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Autopilot - Most autopilots of the type installed in the J41 and it's predecessor the J31/32 are certified down to 200ft on a coupled approach (meaning, autopilot flying the ILS).

 

Speed - Vref is the speed you should normally have at 50ft over the threshold. You have some margin below since it is calculated by 1.3 times the stall speed in landing config, so flying it to the knot is not always necessary or even possible in real life. Care should be taken not to drop significantly below and also not fly too much above Vref since it means you carry a lot more energy down to the runway. Try limits like -5kts and max +15kts.

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and from the time I disengage the AP until touchdown I drift slightly left,

 

If you have any crosswind the runway will not be straight ahead of you because the A/P has adjusted for the wind to hold LOC.  Notice this effect before you disengage A/P and take it into account when holding track to touchdown.  The important visual clue is that the aim point on the runway does not move, it just gets bigger; it will only be straight ahead with no crosswind. It will seem to move towards you if you are too high, away from you if you are low and move laterally if you are drifting left or right.  Off topic but helpful, once you are over the threshold (or sooner depending on weather) shift your focus from the aim point (usually someplace between runway edge and touchdown zone) to the far end of the runway.  Watching the far end of the runway helps you judge your flare and final few feet of descent as well as providing lateral clues.

 

Most important, practice and enjoy good landings.

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WELL...

 

it looks like part of my problem is that I am forgetting to turn off yaw damper before I land (face palm) FO don't tell the chief pilot and I'll buy you a drink lol.

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