FD Pitch Cue Behavior: A Bug, Limitation, or User Error? (v1.3)

[Torbinator]

Hi guys, I was hoping you might comment on whether or not the pitch cue behavior depicted by the flight director on departure was due to a limitation, a bug, or me not using it correctly. In this video you will see how when I move the airspeed cursor from 138 to 220, the FD's pitch cue seems to initially behave somewhat as one might assume for an acceleration by suggesting a lower pitch attitude. However, you'll then see how suddenly snaps up to a high pitch recommendation (twice) even though I have not come near to reaching 220. I narrate the video as it progresses.

Thanks!

 

 

Edited June 1, 2020 by Torbinator

[Litjan]

Your main problem is that you never get out of TOGA mode. Changing the speed in TOGA does not work like it does in FL CHG, because TOGA refers to the MCP speed selection, but will also adjust this (up to selected speed + 20) - because you are supposed to fly at V2 + 15 (unless an engine fails).

So to get proper behaviour, employ the proper procedure: For acceleration select FL CHG or VNAV.

Cheers, Jan

 

[Torbinator]

Excellent, I suspected it might be user error on my part.  OK, so I should do the following:

• TOGA for the takeoff roll and ride the FD pitch cue to V2+15
• At the acceleration height around 1000 AFE, hit FL CHG for the FD to adjust to the bugged speed, or...
• At the acceleration height around 1000 AFE, hit VNAV for the FD to adjust to the programmed profile

Correct?

Thanks!

[Litjan]

Perfect!

Cheers, Jan