ILS suddenly dies in FSX

[Flying_Dutchman]

Hi everyone,

Could there be a bug in the PM-MCP software or in the handshake with FSX? I tried to be as specific and as detailed as possible.

Use Case:

While in final ILS-approach with the glide-slope bug almost in the middle, I push the APP button. Nine times out of ten the plane stays on the same altitude, while the glide-slope bug starts moving downwards. It looks as if FSX doesn't (always) get the message that it should follow the glide-slope. Several re-select attempts do not change the behavior of the plane in any way.

Since only the APP button has this problem, and f.i. the VOR LOC never, I am thinking of a software- or handshake bug. The button lits and when we run the CPFlight test software, the button works 100% of the time, so I don't think it is a hardware issue.

It happens (not always) on crowded airports with heavy scenery like EGLL and EHAM and on desolated ones like EHGG ILS RWY23.

I tried to overrule by pushing Ctrl+A on the FSX-keyboard to see what happens, but since I have deleted all gauches in the config file, I am not surprised that FSX cannot handle the Ctrl+A. Perhaps it should, what might prove something.

As I understood from a friend, who is a professional captain and instructor for KLM on the 737, when it comes to ILS following, the VOR LOC and APP buttons should always overrule any other signal or system when selected.

I fly FSX with automatic generated weather. When in level flight, weather changes sometimes make the altimeter swing like mad. The autopilot and autothrottle do everything to correct the situation. My guess is, that when weather change happens during final approach, the APP button signal gets lost somewhere, because I hear and see the same kind of actions. Since I am on local QNH that should not happen, but it does. First I thought it had something to do with the scenery, so I started to test at EHGG ILS RWY23. Same problem. When I keep up the automatic real world weather generation the problem exists on every approach. When I switch to No weather-Clear sky's the bird follows the glide path like it should. So if I am right, and the problem does not come from another dark corner of all software, it seems that the APP button signal does not always triggers FSX to follow the glideslope. Since this never happens with the VOR LOC, which I used just before I click in APP, I think both signals follow different paths to FSX.

Anyone familiar with this behaviour?


My hard- and software configuration can be found on http://www.b737sim.nl/components.html


Greetings,

Benno

[Michael Carter]

Not sure about the PM problems, but it has been a pretty wild ride across Europe for the last few days. The pressure is constantly changing screwing with the altitude hold and the assigned altitude.

One second I'm 300' below assigned and the next five seconds I'm 500 above.

I've tried the pressure smoothing in FSUIPC but it doesn't work. It seems like FS is trying to get data from several WX sources at once and doesn't know which one to use.

Irritating to say the least.

[mmakela]

Same here! Try reduce FPS to 20. Go to MCP.ini and check You have 80 in
cycle of milliseconds. There is something in FSX and PM.
Pm stuff says the software is ok. Problem can be a A/C model, but I doubt.
I had this with different models.
I hope a fix comes one day.

[mmakela]

...also have You deleted all texts except view config
lines from Your a/c panel.cfg?
try other aircrafts also. When I had deleted fsx sp2 but
kept sp1 some texts started to blink in exam screens?
I suppose the install of rex did not made it?
Never ending misery. I try to solve this g/s problem and
if I cannot fix this I'll go for AST.

[mmakela]

Updates in Pm site!!!

[Flying_Dutchman]

Thanks everyone for the replies!
Seems that we're not alone with this problem...

[JonathanRichardson]

Hi

This problem only relates to FSX. It is known about but only seems to happen on some systems and only sometimes. This makes tracking and solving the problem difficult. It is an on-going issue and we hope to find the cause soon.

Regards
Jonathan Richardson
Project Magenta

[David7700]

Did you try pushing APP well before the glideslope indicator descends toward the middle? It may just not be picking the glideslope up in time, which would cause you to continue at a level altitude. Since you cannot use APP on most APs when you are above the glideslope, try hitting APP before there is any deflection in the glideslope indicator at all. The aircraft should maintain level flight until the glideslope is captured in APP mode, which could be several minutes after localizer capture in APP mode.

[mmakela]

I'll give it a try tonight! Thanks for an advice.
I wonder what are those critical commands or acts that has to be
Performed before locking to the g/s path?

[David7700]

I wonder what are those critical commands or acts that has to be Performed before locking to the g/s path?

I am not sure I understand the question--are you talking about checklist items? If so, I am not sure for your particular aircraft. For light GA aircraft, use CGUMPS:

Carb heat (if applicable--normally aspirated engine)
Gas (fuel--fullest tank, etc.)
Undercarriage (landing gear down)
Mixture rich
Power, props, pumps
Seatbelts, safety, switches (lights, pitot heat, etc.)