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Bentree_

MCP question (autothrottle)

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Hi guy's,

I don't get it....i keep struggling with the Autothrottle.

On Take-Off i select 1.40 EPR and press the autothrottle.

The autothrottle spools up the throttle levers until the yellow EPR limit indicators until  "CLMP" mode takes over, thereafter right away the throttles are overridden by my throttle. When i at that moment have set my throttle to full it runs into a overpowering of the engines and when i have 1/3 of throttle (as needed to reach 1.40 EPR) it runs into not enough power to take-off. So autothrottle is disconnected at CLMP or my phisical throttle is overriding the CLMP mode.

Why is the autothrottle kind of disconnecting (not that it gives a aurial warning though)  right after CLMP?

 

Second issue is when the autothrottle is hunting..... 

In Level Flight i have the settings: FMS SPD - NAV TRK - VNAV LVL and then the autothrottle is hunting.

When i then select "SPD" (to get the IAS speed mode) to prevent the throttle hunting i get the following modes: CLMP - NAV TRK - ALT HLD but when the speed is getting less the autothrottle is not spooling up the throttles or when i gain speed the autothrottle is not decreasing the thtottles.

IMHO the whole autothrottle system is mixed up somewhere.

Or do i make a mistake here?

Thanks in advance for any advice / answer.

Kind regards,

Ben

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30 minutes ago, Bentree_ said:

Hi guy's,

I don't get it....i keep struggling with the Autothrottle.

On Take-Off i select 1.40 EPR and press the autothrottle.

The autothrottle spools up the throttle levers until the yellow EPR limit indicators until  "CLMP" mode takes over, thereafter right away the throttles are overridden by my throttle. When i at that moment have set my throttle to full it runs into a overpowering of the engines and when i have 1/3 of throttle (as needed to reach 1.40 EPR) it runs into not enough power to take-off. So autothrottle is disconnected at CLMP or my phisical throttle is overriding the CLMP mode.

Why is the autothrottle kind of disconnecting (not that it gives a aurial warning though)  right after CLMP?

 

Second issue is when the autothrottle is hunting..... 

In Level Flight i have the settings: FMS SPD - NAV TRK - VNAV LVL and then the autothrottle is hunting.

When i then select "SPD" (to get the IAS speed mode) to prevent the throttle hunting i get the following modes: CLMP - NAV TRK - ALT HLD but when the speed is getting less the autothrottle is not spooling up the throttles or when i gain speed the autothrottle is not decreasing the thtottles.

IMHO the whole autothrottle system is mixed up somewhere.

Or do i make a mistake here?

Thanks in advance for any advice / answer.

Kind regards,

Ben

The system is operating correctly.  I just answered the first question yesterday.  CLMP is the same as HOLD on a Boeing.  Manual movement of the power levers is possible at that point so your hardware can move them.  Push them up into a nullzone or make your nullzone bigger.  

As to the second part are you pressing the IAS MACH button or the SPD button?


Brian Thibodeaux | B747-400/8, C-130 Flight Engineer, CFI, Type Rated: BE190, DC-9 (MD-80), B747-400

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Hi Brian,

I did not ignore your answer from two day's ago. I set more null zone but still the same problem...i will try to set a bigger null zone.

On the second question: i press IAS MACH (Pressing SPD makes the aircraft descent by the way, but the SPD button is in the speed box of the MCP (not in the vertical mode box).

I know this aircraft is different then for example a Boeing.... but it just is not logical / intuïtive.

Regards,

Ben

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Just now, Bentree_ said:

Hi Brian,

I did not ignore your answer from two day's ago. I set more null zone but still the same problem...i will try to set a bigger null zone.

On the second question: i press IAS MACH (Pressing SPD makes the aircraft descent by the way, but the SPD button is in the speed box of the MCP (not in the vertical mode box).

I know this aircraft is different then for example a Boeing.... but it just is not logical / intuïtive.

Regards,

Ben

No you are right. It's not logical nor intuitive.  That's why if you don't pay attention he's gonna nip at you and remind you why he's called the mad dog. :-). You should have just added to that other thread instead of making a new one. I didn't know it was the same person.  I set all my axises in FSUIPC and I personally recommend it.  That way you can ensure there is background noise of the throttles at all.  And if you have done this. Just to be sure you don't have them dual assigned in P3D itself. This will cause a lot of noise.

 

I just wanted to make sure you weren't entering some different vertical mode.  Disengaging the Autothrottle should be on of those functions of pressing IAS MACH.


Brian Thibodeaux | B747-400/8, C-130 Flight Engineer, CFI, Type Rated: BE190, DC-9 (MD-80), B747-400

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Thanks Brian, Sorry for the second topic, i was afraid nobody will see it.

I will try to set the throttle axis in FSUIPC (the joystick is o.k. so i want to leave them as is).

So there is where the "Maddog" name came from.... i like it....it fly's like a charm and is very challenging.

Regards,

Ben

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16 minutes ago, Bentree_ said:

Thanks Brian, Sorry for the second topic, i was afraid nobody will see it.

I will try to set the throttle axis in FSUIPC (the joystick is o.k. so i want to leave them as is).

So there is where the "Maddog" name came from.... i like it....it fly's like a charm and is very challenging.

Regards,

Ben

I don't know if thats where it originated.  But its very fitting same with the -11.  It will keep your eyes moving in my opinion.  Eyes always watching the FMA "Ok, Whats it doing now."


Brian Thibodeaux | B747-400/8, C-130 Flight Engineer, CFI, Type Rated: BE190, DC-9 (MD-80), B747-400

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Different flightsim same aircraft. 4 training movies and a very good information about   IAS, vert speed etc  

 

 

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