ERJ 135/145 FMS does not follow flight plan

[Luis Canas]

I have learned a great deal from reading manuals and watching tutorials on YouTube. Yet I still have trouble with the ERJ 135/145 FMS not following a flight path on autopilot. The FMS is on for sure (purple indications on compass) and I can display the flight path. I thought you activate the NAV button (on the autopilot set) and then the aircraft would follow the flight path. Yet pressing this button activates both NAV and HDG. I can still guide the aircraft along the flight by manually changing heading with the knob but this is not the way it's supposed to be. I must be missing something here. Can anyone in this forum help?

[scoobflight]

Before engaging the NAV are you on an intercept course for the routh's path?

[airernie]

Silly question I know, but have you also pressed the AP (auto pilot button)?     FMS, FD1 or FD2, NAV and AP along with a valid fliight plan programmed into the FMS.

 

BTW, did you create the flight plan or import it into the FMC?  I'm just curious as it shouldn't make a difference.

 

My HDG and NAV buttons are frequently both illuminated, which doesn't appear to create any issues.

 

Ernie

[Luis Canas]

In response to your remarks, at this stage I just create a flight plan in FSX and then have the FMS load it, and I activate the AP, ALT, and HDG buttons at about 2500 ft after takeoff (after I retrieve the flaps at 1000 ft and activate automated climbing). I initially have the heading same as the takeoff runway and then use the knob to line the airplane towards the first vector in the flight plan. Then I activate the NAV button. I expect that the airplane will follow the flight plan as it approaches the vector but then it just wants to follow whatever the heading is set at.

 

I will keep experimenting and reading advice on this forum. Hopefully I can soon figure out the right protocol. So bear with me. I've been using FSX (and previously FS9) for 10 years now but limited to the Microsoft provided planes and some inexpensive payware planes. This more expensive and sophisticated FeelThere ERJ that I bought recently is certainly more challenging, so I will take some beating before I tame this bronco.

[scoobflight]

reads that your are not setting a intersecting course to the flight plan.

[Luis Canas]

I hear you, scoobflight. Reading the description of the FMS training flight in the ERJ V2 manual, specifically paragraphs 2 and 3 from the bottom of page 30, it sounds like I can set the airplane on an intercepting course to a desired waypoint in the flight plan by first steering the airplane with the heading button roughly towards the vector, then displaying the flight plan on the FMS, pressing DIR, pressing the LSK to the left of the waypoint, and pressing NAV on the FGC. Short of trying, tell me if this is right or am I still lost.

[scoobflight]

Yep, what you describe will work.

[Luis Canas]

Success! Thanks for your input.

[scoobflight]

glad to read it worked out.