Waypoints put into FMS...All the other inputs are correct as well (Weight, fuel, VNAV etc)

Take off, get to stable climb then push direct to next waypoint. Push nav button/ap button and acft starts to turn.. Passes intercept point and seems to head back to initial start point...

Any ideas on what Im doing wrong? It has worked before...

Depends on whether the FMC took the first waypoint as being passed. Use 'Direct To' the next waypoint and arm LNAV then.

Depends on whether the FMC took the first waypoint as being passed. Use 'Direct To' the next waypoint and arm LNAV then.

First waypoint is starting airport... The next (direct to) waypoint is about 60 miles out

CZST-PUITY-WETOL-PAKT

Trying to get the FMS to fly me direct to PUITY. The 2 waypoints are part of an ILS approach.. Would that be the problem?

The 2 waypoints are part of an ILS approach.. Would that be the problem?

 

To my knowledge FMCs don't know the nature of a waypoint.

Within SIDs and STARs sometime altitudes/speeds and altitude/speed constraints are bound to them.

Shouldn't be the problem here.

I have sometimes found that the FMS doesn't point the plane in the right direction because it doesn't have the sequence correct in its own memory, even though the order is correct in the FPK page.

 

Make sure that it shows the correct waypoint on the NAV page (use direct to function if not). For a couple of minutes before you reach a waypoint, the NAV page displays the NXT (next) waypoint. Does the plane actually turn where it says it will be going?

 

Another possible problem: i have seen some stars (maybe sids as well, but haven't spotted it myself) where a waypoint in the navigraph data is stored as e.g. "until 20dme (a certain VOR)". For some reason, the Jetsream FMS interprets this waypoint as the specified VOR, and not the point at 20DME. I have not found a solution to this problem yet.

 

Carl Kohrs

I have sometimes found that the FMS doesn't point the plane in the right direction because it doesn't have the sequence correct in its own memory, even though the order is correct in the FPK page.

 

Make sure that it shows the correct waypoint on the NAV page (use direct to function if not). For a couple of minutes before you reach a waypoint, the NAV page displays the NXT (next) waypoint. Does the plane actually turn where it says it will be going?

 

Another possible problem: i have seen some stars (maybe sids as well, but haven't spotted it myself) where a waypoint in the navigraph data is stored as e.g. "until 20dme (a certain VOR)". For some reason, the Jetsream FMS interprets this waypoint as the specified VOR, and not the point at 20DME. I have not found a solution to this problem yet.

 

Carl Kohrs

 

IT seems to want to track to the next waypoint but continues past the intercept heading and back towards an imaginary point...

I had an idea that I havent had a chance to try yet.. I know the default aircraft flight setup has been known the throw things off in this plane so my idea is, making sure the default plabe has the GPS/NAV selector to GPS then save the default. Load up my J41 and flight the way I would and see if that has anything to do with it... Might work, might not but it is a legit idea....

Figured out what it was... on the NAV page of the FMS, if the FR line say invalid, the acft will fly whatever it wants... you have to double click enter so the FMS knows where to track from.. then your next waypoint will be in the TO line and the NAV will follow the input flightplan

Waypoints put into FMS...All the other inputs are correct as well (Weight, fuel, VNAV etc)

Take off, get to stable climb then push direct to next waypoint. Push nav button/ap button and acft starts to turn.. Passes intercept point and seems to head back to initial start point...

Any ideas on what Im doing wrong? It has worked before...

 

Check your SID waypoints one by one because I noticed that FMC creates strange waypoint just after starting airport and if u turn on LNAV directly after TO your plane will turn to this waypoint. Maybe this is the problem only with my JS or specific airports but I almost always have to delete next waypoint after airport. Truth is that if ATC is operating you probably never turn your LNAV on just after TO but you'll get the command "heading" od "direct to". If you have similar problem with SID's in JS41 pls let me know because I don't know is it problem with my plane FMC or AIRAC installed. Sry 4 my poor english.