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Authothrottle arm - manual approach

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Hi chaps,

 

Just getting to grips with the 737. I have an ILS tuned in, both F/Ds on, A/P dual channel APP mode, A/T armed and MCP SPD.

 

I disengage the autopilots and turn MCP speed off but leave the A/T armed. For some reason, using the throttle on my joystick does not work unless I disengage the autothrottle. Does this plane behave differently to the 744 or is this a setup issue I may have? Have looked thought various manual pages but as far as I can tell, I should be able to use the throttle manually with the A/T armed?

 

Thanks for any advice you can offer!

 

Cheers,

Rudy

 

PS also - should I change the cruise altitude on the pressurisation panel when I perform a step climb?

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I tried turning SPD off on the MCP then the A/T switch off, then back to Arm - same way you would on the 744 - am I missing something?

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I tried turning SPD off on the MCP then the A/T switch off, then back to Arm - same way you would on the 744 - am I missing something?

 

Yes, you're missing something.  That's not exactly how you do it on either of those planes.

 

You do not disengage anything on the MCP at all (unless you want to fully shut that system off with either the A/T switch, or the A/P disconnect bar).  Neither of those are wrong, per se, they're just not normal.  Map buttons in the PMDG options for A/P and A/T soft disconnects.  If you look around in the VC at the yoke and throttles, you'll see disconnect buttons.  These are what they use in the real aircraft for normal procedures.  For the captain, it's a (right) thumb click on the throttle and a (left) thumb click on the yoke (two presses for each to tell the automation that the button presses were intentional).

 

Through FSUIPC or a joystick/keystroke mapper, you can send keystrokes with your harware.  As an example, I've mapped CTRL+SHIFT+1 and CTRL+SHIFT+2 to two buttons on my throttle and yoke.  I then went into the PMDG Options menus to set up the AP Disconnect and AT disconnect key strokes as CTRL+SHIFT+1 and CTRL+SHIFT+2.

 

Furthermore, always (always, always) pay attention to your FMA.  Sure, the MCP has pretty lights on it to tell you which modes you've selected, but that doesn't necessarily mean the AP will be using that.  Example: I might have clicked APP, and APP might have a pretty light lit up on it, but HDG SEL or LNAV may also still be lit.  Which one is the AP using?  It's probably still on HDG SEL or LNAV, and to confirm, you just look at your FMA.  The FMA (flight mode annunciator) is displayed at the top of your PFD.  Check it often to ensure that the AP is working in the mode you want it to.  Your goal isn't to "turn SPD off," your goal is to tell the automation that you're in control.  For AT in the 737, hit the disconnect on the yoke.  This will essentially just shut the AT Arm switch off, and there's no real need to turn it back on.


Kyle Rodgers

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Yes, you're missing something.  That's not exactly how you do it on either of those planes.

 

You do not disengage anything on the MCP at all (unless you want to fully shut that system off with either the A/T switch, or the A/P disconnect bar).  Neither of those are wrong, per se, they're just not normal.  Map buttons in the PMDG options for A/P and A/T soft disconnects.  If you look around in the VC at the yoke and throttles, you'll see disconnect buttons.  These are what they use in the real aircraft for normal procedures.  For the captain, it's a (right) thumb click on the throttle and a (left) thumb click on the yoke (two presses for each to tell the automation that the button presses were intentional).

 

Through FSUIPC or a joystick/keystroke mapper, you can send keystrokes with your harware.  As an example, I've mapped CTRL+SHIFT+1 and CTRL+SHIFT+2 to two buttons on my throttle and yoke.  I then went into the PMDG Options menus to set up the AP Disconnect and AT disconnect key strokes as CTRL+SHIFT+1 and CTRL+SHIFT+2.

 

Furthermore, always (always, always) pay attention to your FMA.  Sure, the MCP has pretty lights on it to tell you which modes you've selected, but that doesn't necessarily mean the AP will be using that.  Example: I might have clicked APP, and APP might have a pretty light lit up on it, but HDG SEL or LNAV may also still be lit.  Which one is the AP using?  It's probably still on HDG SEL or LNAV, and to confirm, you just look at your FMA.  The FMA (flight mode annunciator) is displayed at the top of your PFD.  Check it often to ensure that the AP is working in the mode you want it to.  Your goal isn't to "turn SPD off," your goal is to tell the automation that you're in control.  For AT in the 737, hit the disconnect on the yoke.  This will essentially just shut the AT Arm switch off, and there's no real need to turn it back on.

 

 

This is very correct but one little detail, the reason for clicking two times on the disconnect buttons is not to tell the automation that it was intentional cause just one click will disconnect the automation. The second click is to cancel the warnings associated with the disconnection, in the case of the auto pilot  it will stop the auto pilot disconnect sound and the auto pilot warning light on the MIP (note there is a certification requirement for the warning sound to sound for at least 2 seconds), in the auto throttle's case it will only flash the the warning light located next to the AP warning light on the MIP.  So, if you don't click the disconnect buttons a second time the warning lights will flash and warning sound for the AP will continue to sound.

 

 

 

As Kyle said, those lights on the MCP are highly misinterpreted in the flight sim world (and even in the real world by pilots sometimes) They ARE NOT to show what mode you are in, your FMA is showing what modes you are using. In fact the fancy lights on the MCP is only to show what modes can be DESELECTED by pushing the button again. For example when your LOC and G/S capture the APP light goes out on the MCP you can no longer change the mode without pressing TOGA (there is one other way which I won't go into detail about.) 


Patrik Stellgren

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So, if you don't click the disconnect buttons a second time the warning lights will flash and warning sound for the AP will continue to sound.

 

The reason for the warning sounds/lights is unintentional AP or AT disconnects.

 

As such, what I wrote was just fine:

One press to kill it.  The second press to tell the automation that the press was intentional (and, therefore, the alarms can be silenced because the second press confirmed it was intentional and not accidental).  To clarify, I used automation to include the AP, AT, and alerting systems as a whole.  The warning sounds/lights are, of course, automated to kick on and off in response to various conditions.

 

Granted, you're absolutely right that you can kill the AP and AT with one press, and that the second press is what kills the sounds.  That's absolutely right on a functional level.  My post was written speaking to the higher level of the discussion, though: the whole reason for the second press is to confirm your last action, and to minimize the chances of an unintentional action going unnoticed.


Kyle Rodgers

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Hi guys,

 

Yeah you're right - forgot in the real world they use the trottle switches for a soft disconnect.  Have always just tripped the MCP A/T switch off then on again to get rid of SPD mode on the 744 but that didn't work for me on the 737.  I will give mapping those fucntions you talked about a go, Kyle.  I get the stuff with the FMA and MCP :)

 

The main reason I wanted it left armed but not on was for a go-around. was that I was under the impression for TOGA to work - if you press it on the throttles - that you need to have A/T armed on the MCP.

 

Will try your method, Kyle.  I am right in thinking that in order for me to press TOGA and get the autothorttle to advance the engines, I need it armed, right, like the other Boeings?

 

Cheers again,

Rudy

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