One of the most frustrating things that happen while flying the approach on autopilot is to be perfectly lined up on the localizer, properly configured and at approach speed and then watch as the aircraft fails to capture the glidslope on the HSI and descend!!!!!! Hey, the book says you have to "go around," right? But why does this happen? I just flew a perfectly good approach with my PMDG 737 and ended up disconnecting the autopilot and hand flying the approach. Is there no solution to this or is it just hit or miss?Thanks!Airbus

According to the manual, you must always be beneath the glideslope before selecting APR. Just use the heading bug to "get you there".FLYing? It's cool. Trillions of birds and insects can't be wrong.

Hi,I am always beneath the glideslope. As I watch it fall on the HSI is should get captured and cause the aircraft to descend if on autopilot and in the approach mode.Thanks!Airbus

Forgive me for stating the obvious, I never noticed that particular idiosynchrasy. At least you're back to the top now.Best Regards, Donny:-wave FLYing? It's cool. Trillions of birds and insects can't be wrong.

Unfortunately, I have it happen intermittently in any aicraft with APR mode capable autopilots in FS9. It'll keep flying level and blow through the glideslope.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

Which airport / airports?For some unknown reason Microsoft configured the default setting for ILS localizers in FS2004 as "Enable Back Course" being always ON.This creates a problem at many airports in FS which have the same frequency for the ILS localizer on both ends of a runway.Using the same frequency is apparently very common in Europe, though less common in the US, but not unknown - KMDW Rwy 13C/31C - 109.90 on both ends.In the real world the closed end of the runway localizer will not be powered up / transmitting while the other end is active if there is a back course enabled.Flight Simulator cannot do that - turn off a navaid. With the back course enabled - your aircraft may capture the wrong localizer and it will not descend with the glide path because the two signals are from "different" runways.1. If you have a runway with the same localizer frequency on both ends - edit the airport with AFCAD and deselect the Enable Back Course option on BOTH ends. Save the modified AFCAD.2. Always check the IDENT letters for the localizer you are capturing / expecting - make sure it is the correct one for the runway you are wanting to land upon. Most HSI's will display the IDENT code - or you can listen to the morse code for the ident by selecting the NAV1 radio.I've never seen another instance of an airport based problem.The possiblity does exist that it is the aircraft / gauge - unless you have the same problem with several aircraft.Also one other question, is this repeatable? Does it happen every time with the same aircraft at the same airport?Unless a problem is repeatable, it is almost impossible to find the real reason for the problem.

The only time I have this problem is if I try to use FS Navigator and its `fly to here` command, then switch to the ILS/GS on the airport, when the aircraft will consisently fly through the g/s. Dont think I have ever seen it in FS without that, though? As Reggie says, give us the airport(s) and the approachers you're trying.Allcott

Just to clarify (and for the benefit of others), the important thing is that the glideslope receiver is receiving the glideslope and showing you below the glideslope at the time you press the APR button, not just that you be under the glideslope. In other words, the glideslope needle should be at the top, indicating that it is receiving the glideslope and it is above you. If it is not receiving the glideslope the indicator will be centered and pressing the APR button at this time will have unexpected effects.

As someone stated erlier, the PMDG will kick it APR off if you are going too fast for the approach, just like when in VNAV, the autopilot will keep you above 10,000 feet if you are not within 10 knots of 250knots. Ideally you should be at V_ref by the intercept point. When you see the glideslope go active (the dot goes from an outline to solid) gear should start to come down.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

Hi.I get this problem if i fly somewhere with the gps and then forget to turn to 'nav' before catching the glide slope and the plane just carries on regardless. It's lucky I'm only a sim-pilot:P Lemonadedrinker.

Simple solution, do what I do, and hand fly all ILS and BC approaches. It's much more fun, anyway.