CMD A won't engage B does,

[Steff123 0]

Hey,

 

2 main problems here, just a normal departure out of EGKK on LAM4M,

 

once I am around 1100ft I engage CMD a, the airplane starts a climb of 6500 ft/min while my initial alt. is 4000ft.

I switch off the A/P and take over with my yoke to compensate this amazing climb.

Once level, only cmd B engages.

I tried switching off both F/D's and then turn cmd a on again but no luck:(

 

I tried not to compensate with my yoke, but then it breaks through my 4.000ft initial

 

so:

1. Why can I only engage CMD B? Did I broke CMD A?

2. Where does this rate of climb come from?

 

thanks in advance

 

EDIT: Checked my failures:

"FCC_A INOP"

 

Any ideas?

[Levkov 8]

Just a thought, but dId you move the yoke violently with CMD A engaged? If so, you may have broken some sort of autopilot conector pins, there has been talk about it on the forum, but I can't seem to remember the exact name of the thing.

[nrcrate 40]

Here you are: (Quoted from the introduction document)

 

While any autopilot is engaged in CMD mode, yanking at the

controls really hard will result in "breaking" the controller shear

rivets (real value 110lbs of force) and destroy the onside FCC

(flight control center). The associated autopilot cannot be reengaged.

[rsrandazzo 6,353]

Nick-

 

You get the gold-star of the week... This is the kind of detail we put into this airplane that 99.95% of users will never even see...

 

Thanks for being on it..

[ajacied551 1]

Hey,

 

2 main problems here, just a normal departure out of EGKK on LAM4M,

 

once I am around 1100ft I engage CMD a, the airplane starts a climb of 6500 ft/min while my initial alt. is 4000ft.

I switch off the A/P and take over with my yoke to compensate this amazing climb.

Once level, only cmd B engages.

I tried switching off both F/D's and then turn cmd a on again but no luck:(

 

I tried not to compensate with my yoke, but then it breaks through my 4.000ft initial

 

so:

1. Why can I only engage CMD B? Did I broke CMD A?

2. Where does this rate of climb come from?

 

thanks in advance

 

EDIT: Checked my failures:

"FCC_A INOP"

 

Any ideas?

 

First of all try to look up the "FCC" in the FCOM what it means and what the function of the FCC is?!!!!.

 

Let me help you out now!! The FCC stands for Flight Control Computer. There are two FCC's on the 737 FCC A and FCC B.

 

Each FCC has 5 functions:

* Autopilot

* Flight Director

* Altiude Alert

* Speed Trim

* Mach Trim

 

The Autopilot system is a function of the FCC. Autopilot A is a function of FCC A and Autopilot B is function by FCC B.

To switch ON the Autopilot A to CMD you push the CMD A button on the MCP. Well here is it comes!!!? FCC A is INOP in your case. When the FCC is INOP you can push the CMD A switch all you want but it will not operate so you need to use Autopilot B that is a function of FCC B.

[nrcrate 40]

This is the kind of detail we put into this airplane that 99.95% of users will never even see...

And that's why I love PMDG- you guys are awesome.

 

Just trying to help (What I like to do best) :Party:

Thanks Rob

[wilmans 0]

I had the same problem Which i could'nt figure it out. ( i thought it was a FSX or PMDG bug. But when your looking in your FMC aircraft menu, And select Failures. you'll see ACTIVE 2  AUTOMATIC FLIGHT in red.  And thanks to this forum i know why!  (PMDG realism)

[bcrawley57 1]

That explains my issues too, so this still occurs even with failures disabled?

[badderjet 181]

I believe yanking the control column will trigger this failure. Just like your brake heat will add up and eventually fail the brakes, I think it's an inherent part of the simulation.