Non-precision approach - pitch control

I prefer to use VS mode. You can calculate what the VS should be for a 3 degree glide slope by knowing the ground speed. GS times 5 if I am not mistaken.

Another vote for vertical speed (or up-down button as in this case).

Thomas wrote:

…the DN/UP rocker switch is bit difficult( there is always a delay)

I am a bit spoilt in this respect because I can set the vertical speed digitally (even on our Garmin 600 equipped Pa 28). So if you feel that you can control the autopilot in your aircraft more accurately by using the CWS/TCS (every manufacturer uses a different name for it…) button use that one instead! When you release the button in your aircraft, will it hold the last pitch attitude or the last vertical speed? Because in case it holds pitch you will have to adjust it with ever subsequent power and configuration change (which is why I would use VS).

Thomas wrote:

The KAP 150 hasn’t a vertical speed adjustment.

Indeed it doesn’t as it is an attitude based autopilot.

My experience is based on the similar KFC150 but I wouldn’t expect much of a relevant difference wrt pitch control. Accordingly, out of ALT mode (ie ALT annunciator is NOT lighted) the rocker switch controls target pitch of the autopilot. By pressing UP or DOWN the target pitch (ie the pitch attitude the autopilot tries to achieve) will be modified. Pressing the rocker switch for a second changes the pitch by approx. 1 degree (precisely: 0.9 as per the Manual). Practically speaking a “normal” brief pressing of the rocker switch changes pitch by approx. 0.5 degree.

Once understood I found that very usable, even in turbulent conditions it is quite easy to count the number of brief pressings for changing pitch. Let’s say 1 ot 2 brief shots for fine adjustments, and more (or longer) ones for bigger changes.

There is indeed some delay but on the hand that is not to bad as it will avoid overcontrolling. Just be patient the pitch change will come. However, you may want to perform the first big pitch change from level flight to descent manually for the sake of quicker action. This can be done by the CWS button as suggested by @what_next .

The basic information is given in the manual but it seems to lack a proper explanation. See page 35 item “vertical trim” of the King POH:
King KFC/KAP150 POH

The POH seems to suggest that KFC and KAP150 behave similar in this respect.

Thomas wrote:

Thanks all, I will try it next flight immediately.

Let us know how it works! Something that is usually not taught in the course: Don’t wait until the descent point to change from altitude hold to pitch down (or vertical speed), otherwise you will always be high on the “glideslope”. Start descending 0.3 or 0.2 NM before reaching the final approach fix so that you have your 500 ft/min (or whatever results from your ground speed) when passing the fix. We can’t teach that because on the exam, descending before the FAF is not allowed. But in real life it works much more smoothly…

That sounds like an odd piece of obstructionism. OF COURSE one will anticipate the FAF by a few moments, just as one starts down when the ILS glidesope indication is “one dot high”. Only reacting once past the FAF / once the glideslope needle is centered will indeed mess up the approach.

I can’t believe all examiners are that stubborn. As always, it’s also a matter of the candidate “steering” the examiner to some degree. I would actively say “approaching FAF, starting down”.