Xiropillo

Autothrottle and Joystick position

19 posts in this topic

Good evening,

When taking off, I advance joystick throttle axis the required to get enough N2 and when stabilized I click fictitious TOGA button.

The most of the times everything goes fine but sometimes before reaching V1 the power reduces unless I advance throttle to full power.

Which is the correct procedure or setting of the throttle axis using Autothrottle and de rated TO power?

Will I apply full power to engines instead of reduced if I move the axis to full to avoid losing power?

Thanks in advance for your help.

 

 

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1 hour ago, Xiropillo said:

Which is the correct procedure or setting of the throttle axis using Autothrottle and de rated TO power?

Depends on your throttle options, which are set in the FMC PMDG Options Simulation menu (see Introduction document).  Easiest to use is throttles only in HOLD or ARM mode.  The A/T goes to HOLD mode at 80 kts and if you move the throttle or there is noise from the throttle it will cancel TOGA, pretty common problem easy to solve.

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Hi,

First, you adjust N1 not N2 (or is it a typo) to approx 50% then push TOGA button.

What I guess happens here is that if you leave your throttle at the position where you pushed TOGA, then passing 80kt when the AT thrust mode reverts from THR REF to HOLD, the least signal sent by your throttle will bring the levers back the position of your throttle, hence the reduction in thrust.

You have to options here:

_ Either select AT override in the options of the CDU to Never

_ Or, match the position of the thrust levers with your throttle when THR REF is achieved and before the AT reverts to HOLD mode.

Use whatever TO power suitable for your TOW, rwy and weather conditions and use one of the option above.

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Thanks very much.

With NEVER option I have no problems anymore but maybe is the less realistic.

With the second option I have the same problem as I can't set exactly the throttle in the same position and the thrust rises over reduced one or if less the power is not enough.

For sure I am doing something wrong. I will practise in that.

 

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46 minutes ago, Xiropillo said:

With NEVER option I have no problems anymore but maybe is the less realistic.

So it is definitely a signal sent by your throttle (even without moving it).

Is your throttle configured through fsuipc or FSX/P3D?

 

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I did it through P3D settings. But with never option it doesn't move at all. Is how it should be, isn't it?

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Hi,

Yes, we the option set to Never, whenever the A/T is engaged in whatever mode (including Hold) mode, you won't be able to set the thrust with your throttle until you press the A/T disconnect switch.

The most realistic option would be Always as in the real plane you can always override the A/T when moving the thrust levers but the result will be different depending on the A/T mode. 
With A/T engaged in Hold mode, moving the thrust levers will change the thrust definitely until the A/T changes to another mode (THR, VNAV SPD, VNAV PTH...).

In any other mode, a move of the Thrust levers would change temporarily the thrust but the A/T would bring the thrust back to the one commanded by the FMC.

So the most realistic options would be Always. In HOLD only would be a compromise and Never the least realistic option.

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Great! Thanks very much for such a clear explanation.

And sorry again. Which is the realistic option for "Show thrust lever position"?

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4 hours ago, Xiropillo said:

Which is the realistic option for "Show thrust lever position"

That would be "No." You won't find it on real airplanes. This feature was added to the sim because almost no one has throttle quadrants with servos in them that move the throttles. It allows us to precisely place the throttles by hand in the position they would be if we had servos moving them. It helps prevent big jumps when you disconnect the autothrottle before landing, for instance.

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Posted (edited)

38 minutes ago, wsmeier said:

That would be "No." You won't find it on real airplanes. This feature was added to the sim because almost no one has throttle quadrants with servos in them that move the throttles. It allows us to precisely place the throttles by hand in the position they would be if we had servos moving them. It helps prevent big jumps when you disconnect the autothrottle before landing, for instance.

Great. I was wondering that because I have to adjust my throttle axis when disconnecting autothrottle and always had ups and downs with power. Not realistic but good idea.

Thanks a lot. I'll set then "Always" for override and "Yes" for show throttle position.

 

Edited by Xiropillo
Mistaken Never. Is always what I mean
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25 minutes ago, wsmeier said:

This feature was added to the sim because.....

My first readthrough of this thread makes me think that the OP didn't catch this feature -

Read 0.00.73 of the introduction document. Speficically the "Show Thrust Lever Position". This is the "feature" that PMDG added. I have this feature on and the A/T Manual Override to ALWAYS

What I do upon takeoff is advance to 40%, wait a few seconds to verify uniform thrust across both engines (this always happens in the sim) then click the A/T. Then I'll advance the throttles to the programmed thrust setting - which is verified by watching the cyan marker move up to the thrust setting marker. The cyan marker simply shows exactly the position of your hardware. If you move your hardware to exactly the preset thrust marker, when the mode jumps to ARM the throttle will reset to your hardware position... which you just verified should be exactly the same as what the A/T was shooting for.

This is more realistic in that in the event of a failure, you can cut the engines and it will override, and you can go into your shutdown procedure. Also helps if you had some miscalculation or something in that you are running out of runway, you can mash the throttle up and the engines would respond.

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3 minutes ago, Xiropillo said:

Great. I was wondering that because I have to adjust my throttle axis when disconnecting autothrottle and always had ups and downs with power. Not realistic but good idea.

Thanks a lot. I'll set then "Never" for override and "Yes" for show throttle position.

Aren't you physically moving your hardware (and the cyan marker) to where the thrust setting is at in that moment in time? This should eliminate any "jump" in thrust. You will have to physically move the throttles so that they match up every time.. and immediately before you disconnect as the thrust is constantly changing in A/T. 

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5 minutes ago, Nick Dobda said:

Aren't you physically moving your hardware (and the cyan marker) to where the thrust setting is at in that moment in time? This should eliminate any "jump" in thrust. You will have to physically move the throttles so that they match up every time.. and immediately before you disconnect as the thrust is constantly changing in A/T. 

Now I understand that needed movement thanks. I see the meaning of using the blue circle and movement of joystick axis.

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If you turn the A/T back to ALWAYS you will have to physically move the throttles throughout the flight in order to keep them in sync. For example, the N1 continues to rise up as you gain altitude. If you do not advance the throttles physically after the initial setting, by the time you are 3/4 through your climb your hardware might be 15% behind the AT thrust setting. 

Once you start the descent, you'll want to pull the throttles back down to idle. The reasons are all explained in the manuals. 

There are a few other quirks that you'll have to develop a procedure for on approach for example - if you want manual control of the throttles but the ability to kick and have A/T take over thrust upon a go-around... but this is all due to limitations of the fact that the real plane has the ability to physically move the throttles with gears and servos and our game hardware does not. 

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So you all recommend setting ALWAYS for A/T override and YES for showing thrust lever position?

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