'Not on intercept heading'

[Guest Sam_Hampson]

Hello all.Im currently cruising across the atlantic ocean on FS...I accidentally turned LNAV off and when i tried to turn it back on the FMC says 'not on intercept heading'. Does anyone know how i can get LNAV back on??Many thanks

[downscc 1,327]

The bearing to your next fix exceeds a certain angle beyond which the FMS cannot provide a course to it, or more likely, you have flown past a fix or two while VNAV was off.Look at your LEGS page and determine which waypoint on your flight plan is the next one ahead of you then "promote" it to the top line, adjust your heading towards it, and EXEC the change. Now the VNAV should beable to take over.

[Guest Sam_Hampson]

Many Thanks Dan :)

[cavaricooper 2,615]

Dan's method works, another would be to utillize MCP heading to intersect the flight path. Once the a/c is on an intercept heading VNAV can be re-engaged.May I gently suggest a perusal of the manual and lesson plans? I re-read them even today, and learn something each time.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png

[Guest Sam_Hampson]

Hello.Sorry will read it next time!I just flew towards the waypoint and when i was close to the flight path LNAV worked again! Thanks

[BAW9DV 2]

Hi,I understand your frustration here! This seems to happen a lot when you have shutdown FS and then resume a flight sometime later - or when FS has shutdown after a programme crash and you resume the flight with a saved position (with Autosave for example).For some unknown reason, LNAV refuses to engage! I usually turn left or right about 30 degrees using Heading Select - then after 20 seconds I turn back towards the course and re-engage LNAV .... and lo and behold it all re-engages again!Hope this helps,regards,Lee

[JSACKS 0]

It does seem that once you are more than 2.5 or 5 nm away from the magenta track, the intercept angle in relation to the flight track is critical. That said, the distance itself does not necessarily present an obstacle to re-engagement. I have successfully re-armed LNAV (i.e., got an annunciation of it in white on the PFD when pressing the LNAV button) even at a very considerable distance (I think on one occasion I was 50nm off track) once I had deviated from the actual flight track.Jonathan

[Guest D17S]

I get this too on some of my saved, in-route flights. For some reason, my heading slews from/with the gamesave. When I reenter the game, my nose is pointin' (slightly) offtrack as I morph back onto my route. Very realistically, the FMC is having nothing to do with this and gives me the message. (Maybe FSX will reload my airplane a bit more realistically. Will FSX be a bit more "PMDG Qualified?")Right quick, I just go the legs page and select direct to the next waypoint (On the legs page, select the LSK 1R waypoint to the scratch then right back to LSK 1R. Then Execute). Then quickly punch da LNAV button. LNAV will hook right back up and on you'll go. While you're there, give VNAV a punch too. VNAV never (re)engages from a saved flight. (Maybe) this could be FS restarting the airplane at an airspeed slightly offspeed from Vnav's (PMDG's) saved airspeed? The FMC very correctly refuses to reengage? Hard to tell. Here's an idea. We have a graphical, lateral profile annunciation in the ND (the magenta line). The 787 has a graphical, vertical profile annunciation in the lower 1/3rd of the ND. It'll be the airplane's vertical track over (hopefully!) an EGPWS database pictograph. It's much less dos-ish. Colors and everything. What'll they think of next? Hey, about a speed profile? Then I could tell.