cagrikartal

Recycling the Flight Directors

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Hello everyone,

I wanted to ask pmdg if is there a fix coming for flight directors. When you recycle the flight directors, you reset the autopilot and annonciator so the directors on PFD  should disappear which is not the case in pmdg 747/737/777. However this is in 737 i presumed it would be the case for the 747 as they share the same philosophy.

Take Care

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39 minutes ago, cagrikartal said:

I wanted to ask pmdg if is there a fix coming for flight directors. When you recycle the flight directors, you reset the autopilot and annonciator so the directors on PFD  should disappear which is not the case in pmdg 747/737/777. However this is in 737 i presumed it would be the case for the 747 as they share the same philosophy.

Elaborate, please.

When I cycle the F/Ds, the behave as they should.

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38 minutes ago, scandinavian13 said:

Elaborate, please.

When I cycle the F/Ds, the behave as they should.

When you disconnect the autopilot on final for example, you swich the FDs on and off again so that the directors clear on the fd and the autopilot modes are ready for a go around. The reason to do that is to fly the final without an erronous fd indications on pfd after having passed a non-precision minima.

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This procedure sounds like something made up to get around a problem that no longer exists.  I sure do not see this in any of the Boeing documentation.  You have sources?

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7 minutes ago, cagrikartal said:

When you disconnect the autopilot on final for example, you swich the FDs on and off again so that the directors clear on the fd and the autopilot modes are ready for a go around. The reason to do that is to fly the final without an erronous fd indications on pfd after having passed a non-precision minima.

If you have supporting documentation and steps to reproduce, I think you've been around long enough to know that these kinds of assertions should go directly to support:

support.precisionmanuals.com

Still, I'm not quite clear as to what the issue is, in terms of what you think should be happening, versus what is happening.

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I dont have documentation for now but i tought it was known  and clear, tested it on a levelD but anyway.  I will try to find the docs. 

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16 minutes ago, cagrikartal said:

I dont have documentation for now but i tought it was known  and clear, tested it on a levelD but anyway.  I will try to find the docs. 

"When you recycle the flight directors, you reset the autopilot", sorry that is not correct.

Please read this regarding 747:

Flight Director (F/D) Switches

The left F/D switch activates F/D steering indications on the left primary flight display (PFD). The right F/D switch activates F/D steering indications on the right PFD.

ON -

  • on the ground with no autopilot (A/P) engaged and both F/D switches OFF, the first F/D switch positioned ON arms the F/D in the takeoff go-around (TO/GA) roll and pitch modes. Positioning the second F/D switch ON displays the flight direction steering indications on the second PFD

  • in flight, with the A/P disengaged and both F/D switches OFF, the first F/D switch positioned to ON activates the F/D in:

    • vertical speed (V/S) as the pitch mode, and

    • heading hold (HDG HOLD) as the roll mode, or if bank angle greater

      than five degrees, attitude hold (ATT)

  • in flight, with the A/P engaged and both F/D switches OFF, the first F/D switch positioned to ON activates the F/D in the selected A/P mode(s)

    OFF -

  • F/D steering indications do not display, unless

  • a TO/GA switch is pushed when airspeed is greater than 80 knots and flaps out of up

 

 

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Hi all,

During my technical Boeing 747/767/777 avionics training i learned that if you switched off the flight directors
you've got a total AP/FD reset. so i think it is a correct observation from cagrikartal.
Sorry my technical training document are distroyed 😞

Regards
Jo va Bra

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44 minutes ago, downscc said:

This procedure sounds like something made up to get around a problem that no longer exists.  I sure do not see this in any of the Boeing documentation.  You have sources?

Dan, actually this happens from time to time and we turn off FDs and APs and back on to clear whatever went wrong. I agree it's not a common situation but it might happen from time to time.

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killthespam wrote:

"in flight, with the A/P disengaged and both F/D switches OFF, the first F/D switch positioned to ON activates the F/D in:

vertical speed (V/S) as the pitch mode, and

heading hold (HDG HOLD) as the roll mode, or if bank angle greater

than five degrees, attitude hold (ATT)"

This is correct you didn't want a FD signal what is wrong with the actual sitution (within limits). The FD is synchronising the actual situation within the limits about heading and V/S

Regards

Jo va Bra

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Posted (edited)

Hi. AME here ;).

Sorry if you see the word "Figure" here but the not the Figure it self can't be copy-paste them according to my own limitations.

Hope this post solves the Problem.
[MOD: Copyrighted text removed.]







Best Regards.

-S.

Edited by scandinavian13
minor correction

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Thats poor form. We can all read manuals.

This thread wouldve been better served if you rationalised the text instead of lazily slopping that lot onto the pile.

Please refrain from copy and pasting boeing text verbatim and provide references instead. 

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13 hours ago, cagrikartal said:

When you disconnect the autopilot on final for example, you swich the FDs on and off again so that the directors clear on the fd and the autopilot modes are ready for a go around.

I am not even close to being an expert in the B737 systems but what little I do know is that the AFDS is quite different to the B744. I do seem to recall seeing this as a B737 procedure, but certainly not on the B744, because the B744 FDs will engage in HDG | VS and you will indeed have...

13 hours ago, cagrikartal said:

erronous fd indications on pfd

The only time I have ever known it appropriate to "cycle" the B744 FDs on approach is if you need to get out of LOC | GS (e.g. because ATC have offered you a sidestep to a different runway etc). This is because disengaging the autopilot and turning off the FDs is the only way to get out of APP mode without performing a go around. Having got back to HDG | VS you can then re-tune the ILS for the new runway and go back to APP or whatever new mode you wanted.

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RW 747 ops: after taking the autopilot out you can either leave the FDs on and follow them for guidance from the ILS or RNAV, or if you prefer to go visual the FDs can be turned off.

Hitting TOGA in a go around will bring the FDS back in TOGA modes if they’ve been turned off. Then once you select a mode other than TOGA on the go around the FDs will disappear again.

I’ve never heard of the procedure of recycling the  FDs as described on the 744, it must be from other Boeings.

cheers

Jon Bunting 

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3 hours ago, Copper. said:

provide references instead

Read the top ! I have already mentioned the Reference !
AMM - Chapter 22 !!


Regards
-S

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