Originally Posted by
Tomaski
Wait.... what?? You can actually takeoff with the LNAV and VNAV disarmed?!
Yes, I can.
LNAV - normally armed on the ground but I have flown some SIDs where it's not possible due to location of the 1st waypoint. According to OM-B:
Note: For LNAV to be armed on the ground, the departure runway must be selected and the course, to the first waypoint, must be within 5 degrees of the runway heading.
VNAV - my company allowed us to arm VNAV on the ground just last year so before that we used it after clean up. Nowadays armed for take-offs except noise abatement departures - some pilots prefer FLCH, others - VNAV+SPD INTV. On PF's discretion.