CRJ Cruising Level Problems

[kohara]

I purchased the CRJ-200 recently. For some reason I get to my crusing altitude and everything is good and level. But as I fly the plane starts to go up and down and won't maintain my flight level. Any ideas what may cause this?

 

Thanks

Kelvin

[whiskeyportal]

Too much power?

[kohara]

Maybe? I leave it at 90% N1, but maybe I should pull back once at cruise altitude?

[horani]

I have the same, fluctuating at about +/- 200ft from the FL. The reason is definitely not too much power in my case. It is happening with the latest update, I did not have this before.

[kohara]

I have it on autopilot and "ALT CAP" is indicated but I still flucuate over +/- 1000ft at 5000fpm up or down.

[ayarov]

There is an extensive topic about this issue here

 

A workaround exists, it has something to do with the autopilot constants, as far as I remember, the devs did not want to accept it as a bug because not everybody experience this issue.

[cessna729]

Maybe? I leave it at 90% N1, but maybe I should pull back once at cruise altitude?

That would be a start! (or use THRUST LIMIT hint, hint).

 

The Real CRJ-200 is *NOT* an Airbus! .

The Real CRJ-200 has not got an auto-throttle, and  the pilot has to control the throttle.

Javier and Philipp (the devs) have tried to accurately model this in the simulated version.

You the "pilot in command" have to control the throttle, all the FMS is designed to do, if you set it correctly will be to PERF INIT, THRUST LIMIT.( for TGT/TO/CLB/CRZ/MCT etc)..

 

Also all the "speed" button and knob on the control panel do is to maintain a "target" speed when climbing or decending *AND NOT* when flying level (similar thing to selecting VS).

 

Just like the "real" aircraft, the sim autopilot try to control "speed" by changing the pitch attitude (when going too fast it will pitch up, when flting too slow it will pitch down) because it has no auto throttle control.

 

If you want to change this design behaviour (as ayarov suggested), look in the CRJ's aircaft folder for another folder called "User Modifications", look in that for Pitch Oscilation in Autopilot Fix (follow the instructions inside that).

 

cessna729.

Edited April 10, 2013 by cessna729