Simviation Forums

ils approaches using the autopilot in the beech king air or any of the boeings, I pick up the localiser ok, no problems with track, we end up down the centre of the runway, but altitude is not so hot!  King air will fly down the glide slope ok until about 1 mile out, then will hit the ground.  Boeings are all over the place, usually ending with the plane stalling (that is with the ap on, autothrottles set etc).

Any ideas on what I am doing wrong? I'm using correct airport approach plates (jeppsen simcharts) and following vor proceedures etc.

You are intercepting from way out about 1500-2000 feet above the ground and at a 30 degree angle to the runway or so? Then just not touching anything and letting the planes fly the approach. Sure you're on NAV mode (not GPS) and the A/P is set on APR so it automatically kicks off HDG and ALT modes?

Also make sure you're keeping the speeds high enough that the planes can keep their own altitudes. The King Air, 100 knots is a good final speed, the Boeings 737, 125 to 150 knots depending on weight.

heathrow for example, i'm picking up the ils feather (runway 27, 273degrees) as per the approach  from about 10 miles out, at an altitude of 2500, as this is the required altitude from all the local vors.  The glideslope starts at 2500 from 7.5 miles out.  When I get to this point, i am fully established on the localiser with the ap set to nav and app.  I switch off the alt setting on the ap as the gauges centre on the glide slope (altitude wise, we are already centred heading wise) and assume the app setting on the ap should follow the glideslope down?  In a boeing I set the speed on the ap as per the info on the approach plates, having flaps set and gear down.

I mean apr, not app!

hi

Don't switch alt hold off manually. The ap does this for you when it has grabbed the gs. Unless of course you're shooting a loc only approach without gs when you have to manually control alt to hold what is usually a 3 deg gpath (somewhere like London City 6 deg but that's exceptional)

I mean apr, not app!

Actually, APP is correct.

Like Saratoga said, make sure your GPS/Nav mode switch is set to Nav (when you get into more advanced approaches, you can do GPS approaches that transition into ILS, but that's for later.)

Also, make sure to intercept the glideslope from BELOW.  This is imperative.

Thanks for the advice, just had my first good ils landing in a 777!  Letting the ap turn off the alt hold helps, as does keeping the speed up.  Any idea where I can get aircraft data, such as approach speeds, max speed flaps/gear down etc?

Go to your kneeboard, then the reference section.  Approach speed is VREF.  You can print this out from the aircrafts folder in the FS9 directory (thats what I do)

Here are the real numbers for the 777-200  :)
Tried to upload it several times but my internet connection has been very weird the last week or so.  ::)

Where do you find stuff like this Nexus, I never seem to be able to turn anything up  ???

I have the AOM  :)
Both the official Boeing one, and some airlines flight manuals (which the pic above is scanned from)

Ahh, ok, I see, you cheat

Can never be prepared enough, one day I'll need to know most of the stuff in the manuals anyway.
A head start won't hurt  :)

[quote]I have the AOM

Hi RC...I wouldn't totally rely on the AP holding on to the GS like the localizer does...I find that I have to adjust the Altitude (power) or the Airspeed (trim) slightly to keep it on the line. It isn't actually "autoland" so some adjustment will be neccessary...commoner.