I'm running the E Jet V2 Emb 175 in FSX accel pack under Win 7 64bit.

 

Climbing to cruise altitude the FMA shows LNAV and VALT reaching cruise altitude as long as the FMA shows a magenta VALT altitude stays stable. However, if VALT is changed to either a green FPA or ALT neither of these modes will hold the altitude stable - the aircraft starts porpoising up and down by a hundred feet or so. It is continuous. Switch back to VALT stable as a rock.

 

Several observations:

 

1. Porpoising does not occur if FPA or ALT is reached by changing altitude via the altitude set switch and VS switch. Absolutely stable after that.

 

2. For some reason VALT changes to FPA every time I switch views, i.e. an S command is issued. I can't find any list of commands specifically used by feelthere for these jets. I was under the impression the they used standard FSX keyboard commands.

 

3. On forums I found two references to this problem. On one the suggestion was given to uncheck the "Enable support of GF-MCP" in the EMB configuration file. To which the person responded, that solved the problem. In the other case, the exact opposite advice was given, to which the person responded, that solved the problem. I've tried it both checked and unchecked and it made no difference.

 

So any suggestions/comments on:

 

A. Why should FPA or ALT be porpoising at cruise altitude, and how to fix?

 

B. Why should issuing an "S" command to change views switch the autopilot from VALT to FPA, and how to fix.

 

Many thanks

Sorry I can't help because I have some general issues with feelThere and some of their buggy products.

 

John Taylor

Also, wondering why you have to post the same topic 4 times. :(