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Flight Director after takeoff

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After takeoff since the newest hot fix, the flight director doesn't perform as it use to. Normally It pitches for around V2 +20 until I reach acceleration height. At 1500ft climb power kicks in and I retract the flaps to 1, then "Bug up" to flaps up speed. Before the newest hot fix the flight director would lower its pitch to tell me to accelerate to the new speed I have selected. Now it just keeps the takeoff pitch and doesn't lower. Is this correct? Kyle Greene

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I think you are right when flying manually simply at acceleration altitudeincreasing the MCP speed to bug up will not cause the FD to move down in orderfor you to push down the yoke (it did that before the hotfix 4), you have now to push either LEVEL CHANGE or VNAV to accelerate Panos

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increasing the MCP speed to bug up will not cause the FD to move down in orderfor you to push down the yoke (it did that before the hotfix 4)
Yes, that behavior was incorrect. There was a thread about it a few days ago.

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The earlier behavior was wrong - I did a big writeup in a thread about this last week. What's in HF4 is correct now, it was tested in the real airplane. TO/GA = V2+20 (slightly different rules with engine out, can be V2 in some cases) and that's it. If you want to accelerate, press LVL CHG or VNAV (or arm VNAV on the ground).


Ryan Maziarz
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The earlier behavior was wrong - I did a big writeup in a thread about this last week. What's in HF4 is correct now, it was tested in the real airplane. TO/GA = V2+20 (slightly different rules with engine out, can be V2 in some cases) and that's it. If you want to accelerate, press LVL CHG or VNAV (or arm VNAV on the ground).
Ryan, You might wanna re-check this again with your technical pilots as your statement is actually wrong information...HF4 behavior in incorrect! After reading the big write-up thread I agree with your statements about the behavior of the speed bug on the speedtape and the MCP speed value. I disagree when you say that acceleration has to be made in LVLCH or VNAV and cannot be done by following the FD in TOGA mode.I'm even more surprised by this statement as it's actually standard Boeing SOP to accelerate for flap retraction with the FD still in TOGA and to exit the FD TOGA mode by switching to VNAV or LVLCH after flap retraction. When the MCP speed value is increased ABOVE V2 (which was set for takeoff) with the FD still in TOGA pitch mode, the FD pitch bar should drop to command an acceleration towards that new speed. Note that the increment of 20kts is only commanded as long the MCP speed value is left at V2. Once the MCP speed window value is increased, both the value in the MCP and the speed bug on the MCP jump up 20kts (and continue to increase from there afterwards) and the FD in TOGA pitch mode commands an acceleration towards the new speed (no longer +20kts) Best regards, Sylvain Coolsaet Ps: @Tabs: Support Ticket Ticket Number 1E5-1625CAC9-F137 will peak your interest I guess...

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As I've not updated to HF4 from HF3 yet, I've promised myself not to read these sort of threads until SP1 comes out. Then we all have a standard platform for comparison and discussion. These threads sometimes go back across one of more hotfixes and because people don't state which one they're using it gets confusing! PMDG have also admitted there were several unintended side effects from HF4 changes which doesn't help either.

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I disagree when you say that acceleration has to be made in LVLCH or VNAV and cannot be done by following the FD in TOGA mode.I'm even more surprised by this statement as it's actually standard Boeing SOP to accelerate for flap retraction with the FD still in TOGA and to exit the FD TOGA mode by switching to VNAV or LVLCH after flap retraction. When the MCP speed value is increased ABOVE V2 (which was set for takeoff) with the FD still in TOGA pitch mode, the FD pitch bar should drop to command an acceleration towards that new speed.
I'm not sure if that's what Ryan is saying or not, but you definitely don't have to hit LVL CHG or VNAV to accelerate. My company's standard T/O profile (basically NADP-2) is at 1000', BUG UP, N1, Flaps 1. After Flaps Up maneuvering speed, it's LVL CHG and out of 3000', it's VNAV. That's with FMC U10.7 and therefore no VNAV on T/O.

Matt Cee

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So with 10.8 is it still Boeing SOP to engage vnav after flap retraction or before takeoff as described in fcom procedure?

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So with 10.8 is it still Boeing SOP to engage vnav after flap retraction or before takeoff as described in fcom procedure?
When I flew U10.8A, we always armed VNAV on the ground, but selecting VNAV after flaps were up was an option.

Matt Cee

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Nothing kicks in at 1500 ft unless you tell it to !!!Sounds like you are still in takeoff mode.
On Takeoff 2/2 you can specify an automatic thrust reduction height that is independent of any AFDS selection.

Matt Cee

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But climb power does not " kick in " automatically.
Well... it does, no? That's what he said. With A/T enabled for takeoff, thrust *will* reduce to CLB *automatically* at reduction height as specified on page 2/2 no matter what AFDS mode. Don't have to select anything. For acceleration, yes correct. Either bug up, or VNAV will do the job as well if armed beforehand. sig.gif

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