This may be a dumb question, but why is it that sometimes the approach autopilot will fly me down to the runway, and other times it will keep me on course but won't control altitude at all? Is it different between different planes, or is there something I'm doing which is preventing it from working? Last night, for example, flying one of the CRJ addons into Lisbon I just had to take over a few hundred feet up for the final touchdown, whereas flying a 737 addon into Frankfurt I had to control the altitude manually all the way down... staying off the stick just left me pretty much in level flight (and yes, I'm 99% sure I did have the altitude autopilot off :)).Also, is there any way to have the altimeter display altitude above ground level so that I don't have to remember the altitude that I should start the flare at, or try to guess from the scenery?

Each plane is a little different, but you always want to make sure you intercept the glideslope from below. If you get above it, the autopilot will not drop the plane to catch it. As for altitude, some planes will include a radar altimiter which will give you the above ground altitude. I think if you toggle through the shift-z displays, one of the screens also show AGL *I think*.

Yeah, I saw the mention of having to intercept from below in the learning center pages and made sure I was doing that... but the ILS glideslope indicator dropped down past me and the plane kept on flying level.I'll try the shift-Z tonight, the only plane I've see which had a seperate AGL altimeter was the Jaguar addon I downloaded.

No, doing the "shift+z" thing gives you the same altitude as on your altimeter. Well, it does for me anyway!

Suggestions:Make sure you are not overweight for landing so proper control and airspeed can be maintained. Plan your fuel load.Use the heading mode of the AP and the ALT designated to turn the aircraft at the localizer intersection within a few degrees as indicated by the CDI or EHSI. You then engage the APPR mode. Be sure before doing this that if you have been flying with GPS control you switch back to NAV mode.Make sure your airspeed and flap settings are correct so the autopilot can maintain pitch control via trim settings and they don't go out of range for your current air speed and flaps.

And also make sure that the so called "ILS" you are using really IS an ILS (means it has BOTH LOC and GS), not just an LOC (Localizer only) approach--no GS. If there is no GS signal, the autopilot has nothing to lock onto for altitude control. Paul

That might make sense: would it show up differently in the airport information in the map window? AFAIR it just said 'ILS' there.

Paul beat me to it. That is usually the most common mistake, sim pilots not realizing that the runway has a Localizer but not a glideslope. there are 3 flavors of ILS. ILS, ILS/GS and ILS/GS/DME.Willhttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

To really know what you have, get AFCAD221 here in the library. You can use that to check the NAVAIDs present at any airport. Will tell you exactly what components are present. The terminology for the description does not necessarily match what is used on published procedures (which could be different I suppose depending on the country involved), but it is very clear on what components are present. One thing though is standard on published procedures AFAIK--the term ILS means it has BOTH GS and LOC. Not sure if this is true in the map depiction in the sim or not--never use that myself. The readme will guide you through the use of AFCAD. Great piece of software and the readme is top notch--thanks to Lee Swordy for it. Paul

Good comments Will.The 3 flavors you mentioned, I was wanting to know if you have the time to re-list each "flavor with a definition of each.This may clear a lot up on the subject. Also, the ILS Cat I, II and III in relation to minimums may help.Thanks.Mark.

"Also, is there any way to have the altimeter display altitude above ground level so that I don't have to remember the altitude that I should start the flare at, or try to guess from the scenery?"Just about all of Chuck Dome's work includes a handy little gauge which reports altitude AGL--the gauge is present in my Malibu Mirage package (look in the file library under author "John Cillis"). The gauge is small enough to go into any panel...-John

I'll take a crack at it:ILS on a plate means a combination of both localizer and glide slope.LOC means only a horizontal nav localizer is present. You control the vertical track by means of timing passing over certain navaids, or DME measured distance from a nearby navaid.Some ILSs also have a functioning DME and if using localizer only or as backup to a GS, you plan your descent to be at or slightly above the altitude stated at each DME point.An ILS approach becomes a LOC approach if either the GS equipment at the airport or the GS indicating equipment in your aircraft fails.A back course published approach using an ILS is a LOC only approach as the GS will give false readings.Because of the difference in vertical precision without a GS, you will note higher decision altitudes (or MDA).The CAT numbers refer to the complexity of the aircraft's NAV equipment and crew training. The higher the number, the more precision in the airport ILS equipment, aircraft equipment, and crew training. Most changes regarding this are in the forward visibility minimums.Think I got most of it.I do not have the page handy, but the FAA has the AIM (Airmens' Information Manual) on line where you can find more detail on the CAT requirements. I have a hard copy published annually along with current FAA Rules. It makes a very good reference.Large airports having frequent dense fog (such as KBOS, Boston, Massachsetts from coastal fog) have a runway equipped for zero visibility CAT IIIB landings that allows so equipped aircraft to land including I believe an automatic flare.

Ronzie,Thanks for sharing.I was a bit confused with the CAT level info you mentioned. Here is my understanding (I know using the word understanding may be stretched, LOL) both the plane and the field must have the more advanced equipment as it relates to the associated ILS CAT.Also, I was under the thought that at CAT III the plane (once on established app, this means confirmed with the tower i.e...A, extra step to confirm the app path and slope are correct)...The reason of the above paragraph is the following:I purchased the "Air Facts" DVD set by Richard Collins, got it from Sporty's. Any way it clearly stated (on the DVD dealing with AP functions) that once a commercial airliner is on final that the pilot cannot touch the controls until the plane is on the ground (please note they made it clear that "not allowed" meant, as long as they equipment is not having any malfunctions). Please be kind with any coming abuse, its on the DVD. Also, note somewhere, and I can't remember (thus I can't defend the upcoming statement, so easy on the comments I am trying to learn something, LOL). But here we go, the other reference I am speaking of mentioned and also made it clear that one of three landings must be flow to a certain flight level then must be flown the rest of the way by hand to keep current. I have gone thru the FAA manual, (it "ant" short) so I may have missed it, thus a link to the FAA manual would be a repeat. So the way I understand it Richard Collins is a well established Flying Magazine Editor, and again I have watched the DVD over and over. Thus I conclude that maybe his comments were "in general". The reason I say this is I hope LOL, that pilots do fly a few approaches by hand now and then. Then again the may do this during there SIM sessions, as the Sims they use are specific to the plane they fly. This is my understanding, which can be wrong, but I thought the Sim the trained and updated in had to be the same as the plane they fly. So the real question is about the amount of times a pilot must fly by had on approach?One last way of looking at this:If on an ILS CAT III (meaning all the equipment is present on the ground and in the plane for a full landing on AP). Then the Pilot cannot touch the controls unless there is a problem. (Again this is per the DVD set mentioned above.Next, as the other ILS approach (CAT I and II) can

I'm not a real world heavy pilot but I was following a thread with one on another site.For non-CAT III approaches with commercial airliners, they often set standards different than the minimums prescribed by the FAA on approach procedures. Each airline per model and type of approach will specify an AGL at which the pilot must fly the remainder manually, typically 400 down to 200 AGL. There may be insurance factors, experience logging qualifications, etc.In non-IMC weather near the destination, some pilots may request visual approaches to follow the standard pattern that reduces the time in the air by shortening the mileage flown in effect joining the final slope at a later point closer to the threshold but still out far enough to make a practical approach. In this case Tower will give instructions and traffic alerts on how, when, and a requested speed in each phase to merge and land efficiently. Compared to and depending on your heading to destination, this could result in a shorter downwind, base, and final path total. It depends on traffic and other criteria. This is frequently done with aircraft that are not heavies and better qualified for these short range manuvers.In either case, the final may be hand flown even on vectored approach but with following the proper vertical and horizontal established paths so the pilot gets hand flying practice and credit from the airline.Obviously, this would not apply to elevated CAT III procedures, but where ceiling and visibility permit a pilot to request visual once the runway is in site. Depending on the aircraft type, weather and traffic conditions, and airline policy, for lower CAT landings there is nothing preventing from my knowledge a pilot flying an aircraft manually even in moderate IMC as long as the vectors and GS on final are followed as instructed by ATC and in published procedures.