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KirMi

F/D Master lights out of sync?

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Hi Jan,

please no violence in the cockpit:ph34r:!

Before you will kill each other, take a look at this small matrix:

AP_vs_FD.PNG

I've crawled all manuals/documentation I was able to get my hands on, but I can't extract the (????) combinations. The books are not explicit enough on this.

-Michael
 

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Hi Michael,

the autopilot will supersede the flight-director - but the question is - if AP A is in command, but FD switch A is off - will there be a MA light on the left side? I think so.

So maybe the logic is like this: Whenever any FD switch is on, there will be a MA light.

If an AP is in CMD, then the MA light will be on that side, even if that side FD switch is off.

If no AP is in CMD then the MA light will be on the side of the FD switch that is on AND was switched on first.

So your second row would be:

....  B Master .... A+B Master

third row:

...  A Master .... A+ B Master

Jan

 

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28 minutes ago, Litjan said:

Hi Michael,

the autopilot will supersede the flight-director - but the question is - if AP A is in command, but FD switch A is off - will there be a MA light on the left side? I think so.

So maybe the logic is like this: Whenever any FD switch is on, there will be a MA light.

If an AP is in CMD, then the MA light will be on that side, even if that side FD switch is off.

If no AP is in CMD then the MA light will be on the side of the FD switch that is on AND was switched on first.

So your second row would be:

....  B Master .... A+B Master

third row:

...  A Master .... A+ B Master

Jan

 

Thanks Jan,

that's my favorite guess too. Because it seems to be the most logical presentation of the underlying systems architecture to the pilots.

Let's hope, that we can convince Mr. Boeing ;-)

-Michael

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So, if this can be "generally" agreed,

AP_vs_FD_II.PNG

then the red marked states are not yet implemented to Mr. Boeings flavor ;) 

-Michael

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A B737 OM for the -600, -700, -800, -900 versions has a very simple formula for the F/D and CMD relations which makes totally sense for me (despite it might be totally wrong for the classics):

"Master (MA) Flight Director Indicators (white letters)

If a F/D switch is ON, the light indicates which FCC is controlling the F/D modes.
• illuminated – related FCC is controlling F/D modes.
• extinguished – F/D modes are controlled from opposite FCC
• both lights illuminated – each FCC is controlling modes for related F/D."

That would change the matrix - IF it also applies for the 737-300.

Flo

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Hallo Flo,

I've read you post over and over, but I can't find any contradiction?

Beste Grüße

-Michael

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OK, I assume "Master" in the matrix means the related master light (A or B ) should be on.

From the formula I get these results (which differ from the matrix):

CMD OFF = no master light in any case (3rd column)
CMD A + F/D B = no master light (4th column)
CMD B + F/D A = no master light (5th column)
CMD A+B + F/D A = master light A (6th column)
CMD A+B + F/D B = master light B (6th column)

Schöner Denksport, oder?

Grüße
Flo

Edited by FloB
Unwanted Emoticon removed

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Quote

 

Flight Director Display

Turning a F/D switch ON displays command bars on the respective pilot’s attitude
indicator if command pitch and roll modes are engaged. If command pitch and roll
modes are not engaged, the F/D command bars do not appear. The F/Ds can be
operated with or without the A/P and A/T. F/D command modes can be used with
an A/P engaged in CWS.

F/D commands operate in the same command modes as the A/P except:
• the takeoff mode is a F/D only mode
• dual F/D guidance is available for single engine operation
• the F/D has no landing flare capability. F/D command bars retract from
view at approximately 50 feet RA on an ILS approach.

Normally, FCC A drives the captain’s command bars and FCC B drives the first
officer’s command bars. With both F/D switches ON, the logic for both pilots’ F/D
modes is controlled by the master FCC, and both FMA displays show the same
mode status.

The master FCC is indicated by illumination of the respective master (MA) F/D
indicator light. The master FCC is determined as follows:
• with neither A/P engaged in CMD, the FCC for the first F/D turned on is
the master
• with one or both A/Ps engaged in CMD, the FCC for the first A/P in CMD
is the master FCC, regardless of which F/D is turned on first.

F/D modes are controlled directly from the respective FCC under certain
conditions. This independent F/D operation occurs when neither A/P is engaged
in CMD, both F/D switches are ON and one of the following mode conditions
exists:
• APP mode engaged with LOC and G/S captured
• GA mode engaged and below 400 feet RA
• TO mode engaged and below 400 feet RA.

Independent F/D operation is indicated by illumination of both MA lights. When
independent operation terminates, the MA light extinguishes on the slaved side.
If a generator is lost during a F/D TO or GA, or while in dual F/D APP mode
below 800 feet, the FCC on the unaffected side positions the F/D command bars
on both attitude indicators. If the F/D MA light on the affected side had been
illuminated, it extinguishes upon electrical bus transfer.

 

 

....maybe this snippet (even from 737NG OM) makes it nearly deterministic.

-Michael

p.s.: I can see clearly now, but my brain is gone...;) 

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Yeah, I love it when manuals are clear and concise and leave no room for misinterpretation. Here is my favourite one:

 

Quote:

 

There appears to be some confusion over the new pilot role titles. This notice will hopefully clear up any misunderstandings. The titles P1, P2, and Co-Pilot will now cease to have any meaning, within the BA operations manuals. They are to be replaced by


Handling Pilot,
Non-handling Pilot,
Handling Landing Pilot,
Non-Handling Landing Pilot,
Handling Non-Landing Pilot, and
Non Handling Non-Landing Pilot.


The Landing Pilot, is initially the Handling Pilot and will handle the take-off and landing except in role reversal when he is the Non-Handling Pilot for taxi until the Handling Non-Landing Pilot, hands the handling to the Landing Pilot at eighty knots. The Non-Landing (Non-Handling, since the Landing Pilot is handling) Pilot reads the checklist to the Handling Pilot until after Before Descent Checklist completion, when the Handling Landing Pilot hands the handling to the Non-Handling Non-Landing Pilot who then becomes the Handling Non-Landing Pilot.

The Landing Pilot is the Non-Handling Pilot until the "decision altitude" call, when the Handling Non-Landing Pilot hands the handling to the Non-Handling Landing Pilot, unless the latter calls "go-around", in which case the Handling Non-Landing Pilot, continues Handling and the Non-Handling Landing Pilot continues non-handling until the next call of "land" or "go-around", as appropriate.

In view of the recent confusion over these rules, it was deemed necessary
to restate them clearly."

 

:o

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...

2 hours ago, Litjan said:

Handling Pilot,
Non-handling Pilot,
Handling Landing Pilot,
Non-Handling Landing Pilot,
Handling Non-Landing Pilot, and
Non Handling Non-Landing Pilot


Monty Python's Flying Circus?

Like the old "...Ham and Spam?" Stuff! :lol: "...and now something completely different":

I've just booked an 2h 737 Sim-Session at LH Flight Training. So, if the instructor cooperates, I'll walk thru all the F/D and A/P modes and fill in the above Matrix.

Beste Grüsse,
-Michael

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7 minutes ago, FloB said:

That's dedication! And a deep wallet

 

More coincidence and less dedication! ;)
I've planned it since last year. And now it'll be the last chance to meet these "old aunties" here (FRA/SFX).
And you are right, it bites the wallet.

-Michael

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On ‎29‎.‎06‎.‎2016 at 6:48 PM, KirMi said:

So, if this can be "generally" agreed,

AP_vs_FD_II.PNG

then the red marked states are not yet implemented to Mr. Boeings flavor ;) 

-Michael

Hi Folks,

back from "test-flying" at LH-Training/Berlin. I've tested all the above combinations in their Full-Flight Sim (FT38) and it's implemented exactly as shown in the table above.
But the rightmost column (CMD A+B) needs a little clarification: The indications are only valid thru dual channel approach operation. In the mean time, between engaging the 2nd A/P and transitioning to dual channel mode (after the self-test) the master indication stays on the side of the 1st engaged A/P ;-)

-Michael

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Hi Michael,

thanks for taking the time and effort to validate this in the full-flight sim! I will check again in our upcoming patch to see if we are good...

Cheers, Jan

 

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