Waypoint sequencing after lift-off before LNAV engages

[Hardy Heinlin]

Good evening,

here's an interesting side effect of the LNAV engagement criteria inhibiting the engagement.

For example, load:

01 Departure 002 - Tel Aviv - Hong Kong.situ

On Instructor > Situation > Malfunction > Self-induced select engine failure 1 & 2 after V1.

On THRUST LIM page, select:
TO-2 at 4L
Clear the scratchpad
Enter 66 in 1L (wait 5 seconds till the entry is computed)
Select TAKEOFF at 6R

On TAKEOFF REF page, push 1R, 2R, 3R, 4R.

Press F11 to let the virtual pilot do the takeoff.

Now watch the sequencing of the waypoint BGN/01 while the aircraft is airborne with LNAV not engaged yet.

LNAV is supposed to engage when all engagement criteria are met.

In this scenario, the 50 ft criterion is met, but the aircraft is not on an intercept heading to the leg to NOGAH. So LNAV will not engage.

Due to the low-power takeoff, LNAV wasn't engaged before passing BGN/01.


Cheers,

|-|ardy

[emerydc8]

Interesting scenario, Hardy. It's situations like yours above, and like this http://aerowinx.com/board/index.php?topic=3751.msg39015#msg39015, where you can't always rely on LNAV to keep you out of trouble.

Jon