To add to the discussion; BusFlyer, the FMC will not sequence the next active waypoint if One deviates more than 21nm. This is important to know as the FMS will not advise you - the only way you’ll know is by looking at the top right corner of your ND and noting what is the waypoint in magenta i.e. the active waypoint.
Also, prudence would dictate that once you are deviating away from the LNAV magenta line (i.e. HDG SEL or TRK SEL), a quick check of the GRID MORA, Minimum Radar Altitude(s), or if within 25nm of the navaid (or ARP) predicated sector MSA, to ensure you will be clearing any obstacles or terrain thus an alternate technique is to use FLCH or VS, update your LEGS page with the amended active waypoint (as per Rudestuff - Post #4), then look at your PROG page and calculate mentally whether you are high, on or below your nominal descent profile. This can also be backed up using the dynamic arc and technique that Commander Taco Post #6 posts.
In essence, there’s various techniques; but certainly have an awarness of what’s adjacent once you’re leaving the LNAV track combined with where the dynamic arc is defined on your ND.
Apologies for the long winded answer.
Safe skies always.
Last edited by Gweilo747; 8th Oct 2022 at 19:30.
Reason: spelling error