I'm wondering if this problem has anything to do with attitude. With some aircraft you can get the nose too high, to the point where the antennae can't see down far enough, so the ILS loses it's capture.

Has anyone tried flying the ILS at a higher speed?

Mark, I too use YMML and YBBN with all the FTX areas and I saw a guy on their forums post up some figures on GTX470 and 480. My 5870 was around the same fps as his 480 but at a higher resolution. My 1920x1200 vs his 1680x1050. They are very good as long as you use Jesus Altuves SM3 mod. (That stops the stuttering in heavy cloud) The ATI have a bad rep in the FSX world for some reason but I can assure you they work as well if not better than a 480. Jesus Altuve himself said he regretted selling his 5870 after he discovered the mod.
The worst I get is mid teens at YMML in the 767 vc and that's usually when there's a lot of traffic. (My Traffic 2010)
So if cash is an issue then I can highly recommend the 5870.

It amazes me how far and wide FUD can spread and the fanboys who spread it should be ashamed. We are supposed to be helping each other out, or so I thought. (I should mention that wasn't aimed at anyone here)

/Rant.

Red STar wrote on Sep 7^th, 2010 at 6:36am:

See my reply in the other AUTOPILOT thread.

Mark

Yes I am. With the ones that aren't successful, I blame myself (pilot error) because I've stuffed up somewhere on my approach. Because I either fail to lose enough altitude in time or I lose too much too soon are the main reasons.

Mark

Autopilot operations on the CS-727.

I have Ver 2.4.

Just flew a bunch of ILS autopilot approaches to see how the CS-727 works. It is remarkable how this software simulates the real 727.

The key to a autopilot approach is not to hurry the poor autopilot. Remember this is 1950's state-of-the-art stuff so you can't expect 757, 767, or Airbus navigation or electronics. In the real plane you need to be set-up for the approach long before intercept...no different here!

Get all the radios set to the correct frequencies and set the course on the HDI to the ILS inbound course. You can get the correct freq. from the MAP drop-down. Just mouse over the ILS for the runway you plan to land on and the ILS information will appear.

As you fly in the traffic pattern have the autopilot in MANUAL or HEADING SELECT with ALTITUDE HOLD engaged. You can steer the plane in heading select and work yourself toward and intercept heading.

Here are some ball park or canned speeds to fly in the pattern:
Landing weight 125,000 to 130,000#
CLEAN - 230 KTS (not less than 200 KTS)
FLAPS 2 - Not more than 230 KTS not less than say 180 KTS
FLAPS 5 -between 180 and 160 KTS
FLAPS 15 around 150 KTS

As you get close to the ILS intercept be at FLAPS 15 and around 150 KTS. This will give you a better degrees per second turn rate thus giving the old autopilot a better chance of success. (the faster you go the slower the turn rate for a given bank angle)

You can select AUTO-G/S anytime during your vectoring for the intercept. The autopilot will remain in HEADING SELECT until LOC intercept.
You must remain BELOW the G/S and intercept the LOC first.

I set up the plane on an intercept heading of around 30 degrees to the localizer and on the initial approach altitude for the ILS selected and about 10 miles from the airport.

I set up the autopilot & F/D in altitude hold and heading select.

I select G/S AUTO on both the autopilot and the F/D. I am flying at 150 KTS with flaps 15 which is a normal setting for this phase of the approach.

Give the autopilot a chance to do it's thing by not rushing the approach.

As the LOC comes alive, the autopilot and F/D will captured the LOC and intercept. The heading select will trip off.  With the LOC captured and the plane at 150 KTS and flaps 15 degrees I am now trucking towards the runway. As the G/S comes alive select gear down. One dot to G/S intercept select flaps 30 degrees and as the plane pitches down at G/S intercept adjust power to maintain speed. For these approaches I set the fuel load to 20,000 # and I used around 125 KTS on final.

Note on the F/D... To get "all angle capture" by the F/D you must first select HEADING SELECT and be in that mode for a few seconds before selecting G/S AUTO. The F/D will remain in heading select and can be controlled with the heading knob up until capture of the LOC. If you do not do this heading select first and go directly to G/S AUTO the F/D will program a 45 degree intercept. Not a big deal, but this will give you the option of guiding the plane to an intercept heading during vectoring.

Take note of the approach progress display group of lights on the instrument panel. They show the modes of the autopilot and the F/D as they go through the various arm & capture modes.

Make smooth and slow power changes and try to hold a constant speed. Every speed change will result in a pitch change and thus a trim change and the approach becomes unstable. I use FUEL FLOW to set power. At 30 degrees flap at this weight around 2,000 to 2,500 FF should be close. Adjust smoothly to stay on speed.

The 727 is not an auto land plane so you must disconnect before touchdown. 

MANUAL G/S was only used:
When above the glide slope or on an extended (long) approach.

Once the ILS is captured by the autopilot a timer starts in the autopilot. As the aircraft gets closer to the runway the LOC and G/S get more sensitive. Boeing designed the glide slope to begin desensitization as the plane would get closer to the runway. In the 727-100 this was based on time. (the 727-200 used the radar altimeter - much better! Did not need to use this procedure.)

So, if you are on an extended (long) final and you have intercepted the ILS at a higher altitude the G/S would need to be re-sensitized during the approach. Here is how you do this: While in AUTO G/S and on LOC and G/S, you select a non radio mode - HEADING SELECT, then select MANUAL G/S quickly by pushing down on the switch and move to MANUAL G/S. Folks, this is way too detailed for this simulator. Just don't fly too long a final and intercept at a higher altitude. You can fly a 50 mile LOC (done sometines in KLAX or KLAS) just don't select AUTO G/S until 7 or 8 miles out.

I hope this information helps. It's a bit technical, but simmers like myself enjoy the detail. I find this CS-727 to be a blast and a lot of fond memories of the old plane which was always fun to fly.

Remember this is a "game" not a multi-million dollar simulator. I think it's a great simulation and it flys pretty much like the real thing which was not CAT-II. Give it a try and don't rush the approach and it will do a good job.

Lou