Hi Everyone,

 

On my last four flights, RC started to have a strange behaviour when approching my destination. It tells me to descent to FL120 "in 30 miles or less", what I do. On my four flights, I was level at FL120 at least 45 miles from the airport (RC usually ask to contact approach at 40 miles). However, RC told me that I missed my crossing restriction and asked me to turn.

 

When it happened the first time, I turned but RC let me on heading for several minutes and I flew more than 30 miles before I decided to disobey to ATC and went back on track. RC asked me several time to change direction before finally asking me to contact approach (I was about to capture the localizer).

 

On my next flights, I decided to not follow what RC told me and it asked me to contact approach very late too (and never told me that I was not on my assigned altitude as I was descending).

 

Om my last flight, I tried to change the altitude setting option to 2000ft to see if this was due to RC not seeing the same altitude as the simulator, but the same happened. Even worse, approach never asked me to contact tower...

 

Also tried to do a scenery update, but no luck.

 

Any ideas what can cause this?

 

Thanks a lot.

Fabrice

Standard baro setting versus local baro setting, maybe?

 

If RC is talking about flight levels, you must be on STD. If RC is talking about altitudes, you must be on QNH (the one RC is aware of).

 

Differences in baro settings could account for a couple of 100's of feet, and RC would not tolerate that.

That was what I was going to suggest.

If you fly in the USA and then in Europe, you get TA differences which can catch you unawares. And RC also has TA's at less than 10000'.

I have had this previously, before I became aware of what I was  doing.(Automatically pressing the STD button off at 10000').

U can fly approach with RC4 in two ways, either u follow RC commands strictly or u fly ur STAR procedurę and do not follow RC guidance but then u ask for IAP approach.

Thanks for your replies, guys.

 

I thought of the Baro setting, but this is not the problem. I tested during two flights, and the difference was only about 200 feet between STD and local, so this should not interfere with the altitude tolerance in the settings (2000ft in my last flight). Anyway, flying in Europe, I was in STD.

 

@Artur. I usually use IAP approach, but I have to contact approach first, and my problem is RC not telling me to contact it as it pretend I'm not at the right altitude.

 

Fabrice

Fabrice,

 

Post departure and arrival ICAOs please. That will give us a better idea of the problem. But if this problem has only started in your last 4 flights it suggests you've changed something either in RC or elsewhere.

Setting in RC an altitude window of 2,000 feet can also cause "unexpected behavior".

 

Remember that FS reports true altitude and baro pressure, not pressure adjusted adjusted altitudes.

 

Crossing restrictions are hard coded in RC and you will not advance toward destination until you meet the crossing restriction. The use of the NOTAMS and IAP options will not get you around this. Neither will a direct-to. Insure that you have acknowledged all RC controller commands as it may pause your aircraft status/position monitoring if you do not do so.

 

A crossing restriction is the altitude where hand-off between center and approach controllers takes place just after 40 nm out from destination.

 

For a Boeing type Smith's FMC you can put a 40 nm range ring around destination using the following procedure. Bring up the FIX page and enter the ICAO of the destination airport. In the distance/bearing field enter /40. EXE the change and on the nav display you'll see the dotted line circling the destination airport. You can then use the descent trend arcs  displayed to insure you are at the required limit. If you are using VNAV and you have a checkpoint at or just before the range ring you can hard code the altitude on your LEGS page after you receive one of the two (11,000 feet/FL110 or 12,000 feet or FL120 depending on arrival direction). Consider also adding a 30 nm range ring which represents the traffic area for the airport where speed restrictions come into play.

 

Finally, as always, be sure your fsiupc is current from the provided links.

Ray, here they are:

1st flight: LSGG - EDDS

2nd flight: EDDS-LSGG

3rd and 4th flight: LSGG-LFBO

I did not change anything, only the altitude option set to 2000ft for my 4th flight.

 

Ronzie, thanks, I will reverse the altitude setting to 300ft (that's the default value, right?). I always acknoledge all RC requests. I'm using Aivlasoft EFB and the rings on the map shows I'm more that 40 miles away from the airport when level at FL120. Also, RC gives me the distance to the airport on the RC window (which was at least 45 miles on my four flights.). Then, when reaching 40 miles, RC tells me that I missed the crossing restriction.

 

Thanks,

Fabrice

Hi Fabrice,

 

All European destinations so you must be on STD pressure when reaching 40DME from arrival.

 

The change of the altitude option from 300 to 2000 has almost certainly caused this problem. I'm sure once you revert it you'll have no further problems.

 

For the LSGG departures and arrivals make sure you choose NOTAMS as there are altitude restrictions. You don't want RC vectoring you into a mountain! :wink:

Thanks Ray, I will try.

Most of my flights have LSGG as departure or destination (I live ~100km from there...), and I always use a SID or a STAR (using the IAP approach option), so no problem with the mountains... :-)

 

Thanks a gain,

Fabrice

Hi Fabrice

 

I have also run into this problem before, my "solution" is to descend an altitude that is a couple hundred feets below instructed, (ex 11800ft).

 

I can see that this is not preferable, but it allows me to continue my approach

Thanks Ray, I will try.

Most of my flights have LSGG as departure or destination (I live ~100km from there...), and I always use a SID or a STAR (using the IAP approach option), so no problem with the mountains... :-)

 

Thanks a gain,

Fabrice

 

Lovely country Fabrice. My nephew lives near Lausanne so I'm familiar with LSGG in FSX and the real world.

Hi Fabrice

 

I have also run into this problem before, my "solution" is to descend an altitude that is a couple hundred feets below instructed, (ex 11800ft).

 

I can see that this is not preferable, but it allows me to continue my approach

 

Hi Audun,

 

I would advise against that. if you have the default altitude set in Options you will probably be told by RC you're not at your assigned flight level.

 

Adjust it as has been suggested and providing you keep on STD pressure you will encounter no problems with RC if you remain at the FL it has instructed.

Hi Ray

 

I see what you are saying, but it still is a problem, and it is always present when the pressure is at either the low end or high end.

 

The point is, my "solution" works fine for me, there is no consequences, and we have to remember that this is not real world.

 

But thank you very much for your response, I really appreciate your contribution to this forum, and RC in particular.

Hi Auden,

 

I won't labour the point but RC will work correctly even in extreme pressure situations. Just before Christmas the UK was battered by multiple low pressure systems. My weather station recorded its lowest pressure since I started keeping records with a low of 964hPa. It was even lower at Glasgow when I had a flight there out of curiosity.

 

With default options settings RC performed absolutely fine.

 

Thank you for the compliments. :smile:

Hi Guys,

 

I did not have the opportunity to fly again before today. I made two flights with 300ft in the options and everything went well. Thanks to all for your help.

 

Fabrice