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757 Captain III >> 757 Captain III - General >> A/T throttle flickering/seeking
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Message started by Shom on Jun 2nd, 2018 at 5:57pm

Title: A/T throttle flickering/seeking
Post by Shom on Jun 2nd, 2018 at 5:57pm
This is in regards to the auto-throttle - the throttle levers jump back and forth when climbing in FLCH mode (quickly, very unrealistic)
In regards to the auto-throttle and VS mode - when descending using VS mode and using SPD mode when reducing the speed to be maintained during the descend the auto-throttle can not maintain idle thrust - and jumps instantly to max thrust (and back to idle vice versa...) never managing to reduce the thrust to maintain the desired airspeed.

Title: Re: AUTOPILOT (MCP part only)
Post by Thantheleon on Jun 2nd, 2018 at 7:39pm

Shom wrote on Jun 2nd, 2018 at 5:57pm:
This is in regards to the auto-throttle - the throttle levers jump back and forth when climbing in FLCH mode (quickly, very unrealistic)
In regards to the auto-throttle and VS mode - when descending using VS mode and using SPD mode when reducing the speed to be maintained during the descend the auto-throttle can not maintain idle thrust - and jumps instantly to max thrust (and back to idle vice versa...) never managing to reduce the thrust to maintain the desired airspeed.

This could be caused by the throttle resistors noise. Please try to unplug the throttles.

Title: Re: AUTOPILOT (MCP part only)
Post by Shom on Jun 2nd, 2018 at 8:12pm
I am using a simple Logitech joystick with a built-in throttle lever.

Title: Re: AUTOPILOT (MCP part only)
Post by Shom on Jun 2nd, 2018 at 8:57pm
Weird issue is that I've experienced it inconsistently. Some flights were perfect and in some the auto-throttle was unmanageable as described above.

Title: Re: AUTOPILOT (MCP part only)
Post by Thantheleon on Jun 2nd, 2018 at 10:48pm

Shom wrote on Jun 2nd, 2018 at 8:57pm:
Weird issue is that I've experienced it inconsistently. Some flights were perfect and in some the auto-throttle was unmanageable as described above.

Any resistor joystick can produce a noise. A/T may consider the noise as a pilot's input and break the whole A/P logics. The only way to find out is to unplug the joystick and test all A/T modes. 

Title: Re: MISC
Post by ai1 on Dec 28th, 2018 at 3:57pm
P3DV4.4  757IIIv1.3
With auto throttle on, engine 2 still responds to joystick throttle lever 2. Throttle 1 has does not react to the joystick (as intended ?). Moving the joystick levers then creates an asymmetry in  throttle positions that is not recovered by the auto throttle.
It is as if the auto throttle only disregards joystick throttle lever 1 when engaged. 
Input is done via fsuipc as normal FS axis. 
Thanks.

Title: Re: A/T throttle flickering
Post by ai1 on Dec 28th, 2018 at 5:32pm
A correction to my previous post. It only happens when both throttle 1 and throttle 2 joystick levers are moved together. But it results in only simulator lever 2 moving. When only moving joystick lever 1 the sim ignores it, same for lever 2 (when auto throttle on). When moving both joystick levers at the same time the issue occurs.
The implementation of the auto throttle should either ignore any movement of joystick levers or react to any of them individually. At the moment it is impossible the first set the joystick levers in a roughly correct position before disconnecting the auto throttle.
Thanks.   

Title: 757PF Autothrottle
Post by deonjonker on Feb 1st, 2019 at 11:04am
Something funky with the AT in this girl. She'll go from full power to idle at random intervals. Visually, you can see the actual throttle jerking/stuttering.

I have the latest update installed for both the base pack and the Freighter Expansion.

Title: Re: 757PF Autothrottle
Post by deonjonker on Feb 1st, 2019 at 11:50am
Here's video link: youtube[dot]com/watch?v=N9s955PQ0og

This was during cruise.

Title: Re: 757PF Autothrottle
Post by Captain Sim on Feb 1st, 2019 at 4:10pm

deonjonker wrote on Feb 1st, 2019 at 11:50am:
Here's video link: youtube[dot]com/watch?v=N9s955PQ0og

Nice video, thanks.
Same reason explained above.

Title: Re: A/T throttle flickering
Post by Colvale on Feb 1st, 2019 at 9:44pm
Unlike that weird behaviour in that YouTube clip, my A/T and EPR ratios are as attached which is exactly what I watched in a R/L DVD of a flight from EGCC-Dalaman. So, no flickering throttles or the EPR ratios tumbling one minute climbing the next.

Flickering will happen if in x4 compression as I noticed.
AT_EPR.JPG ( 175 KB | 148 Downloads )

Title: Re: A/T throttle flickering
Post by Markoz on Feb 1st, 2019 at 10:50pm
Starting off with a Logitech Extreme 3D Pro joystick, then onto a Thrustmaster T.16000M FCS joystick, and now a VKBSIM Gladiator MKII joystick, and the throttles on the 757 have never done what is seen in the vidio, nor what those with the problem are describing. All is well for me, and always has been.

Title: Re: A/T throttle flickering
Post by KG1000 on Feb 2nd, 2019 at 7:24am
I have the X55 warthog. When I first bought the 757 I also found the throttles in the cockpit flickering. The solution was a simple one though. Once the auto throttle was engaged, I pulled my throttles back to zero. Not sure if that is the same issue as others are having here, though.

Best,

Keith

Title: Re: A/T throttle flickering
Post by Captain Sim on Feb 2nd, 2019 at 2:58pm

KG1000 wrote on Feb 2nd, 2019 at 7:24am:
I have the X55.

It's a conventional resistor joystick which can produce a noise.
The A/T considers the noise as a pilot's input and break the whole A/P logics.

This is an example of what you need to enjoy the 757:
- 3D magnetic sensors (Hall Effect) on the 2 throttles: enjoy surgical precision that stays razor-sharp over time.
- 14-bit resolution (16384 values) on each throttle.


Title: Re: A/T throttle flickering
Post by Markoz on Feb 2nd, 2019 at 4:03pm

Captain Sim wrote on Feb 2nd, 2019 at 2:58pm:
This is an example of what you need to enjoy the 757:
- 3D magnetic sensors (Hall Effect) on the 2 throttles: enjoy surgical precision that stays razor-sharp over time.
- 14-bit resolution (16384 values) on each throttle.

I'm not sure if my VKBSIM Gladiator MKII uses the Hall Effect, or has 14-bit resolution, but my Thrustmaster T.16000M FCS did, and it's the best joystick I've had.

Title: Re: A/T throttle flickering
Post by ZS-RES on Feb 11th, 2019 at 9:52am
Good Morning

Herewith some positive feedback.

Yesterday I uninstalled every file/folder regarding the CS B757 III.
I then down loaded the 3 x files IE: base + update + freighter.
I installed these files in the same order as per the prescribed guidelines noted in this forum.
Disabled the AV also the Windows defender.
The only thing I did not do was update the Navigraph file.

I then selected a airport EGNX with RWY09, ALT FL330 and runway HDG.
I used the PW freighter model with zero cargo and 11.7 tons of fuel.
I did not program the FMC.
Set the flaps and took off maintaining RWY heading.
At 1800' I activated the AP, selected the FLCHG and "played" with the speed in the climb until FL330.
About 5 min after activating the A/T I pulled the throttle of my J/stick back to ZERO.
I climbed to FL330 at various speeds without the T/Levers "moving" backwards and or forward.
I flew at FL330 for about 10 min and then started the descent to FL110.
First I selected a descent SPD of 270 Kts after 5 min changed it to 285Kts.
After about 7 min I decreased the speed to 238Kts, and this happened as normal with the A/C slowly decreasing its speed.
I then flew at FL110 for about 6 min and then decreased the speed once again to 185 Kts, staying at FL110.

Conclusion is that whilst all this was being done with selecting the diff speeds the T/Levers never did what it did with my previous experience.
With that said I must also admit that I did not have the 1.301/02 installed, when flying the "problem flight"

I shall get to a proper flight with the FMC programmed, and the AS16 also running together with FSX-SE. I run Win 7 64bT Home Edition.

I am using a very cheap J/stick with the "twist" function and 1 x throttle.

Hope that the "pulling back" as someone wrote earlier in this forum solved my problem.

Will keep you posted/ updated on this matter.

Regards

Ricardo S
ZS-RES

Title: Autothrottle - cruise
Post by Ian Bowden on Apr 30th, 2019 at 12:44pm
Hi,

I'm onto my second flight today - having had the aircraft for some time but not really flown it. It is up to date.

The autothrottle holds climb power exactly as commanded but once level in the cruise it seems to be 'seeking' all of the time, and the throttle levers move constantly. This is not the case in the real aircraft - certainly not this sensitive.  Is there a fix planned?

Thanks.

Ian.

2019-4-30_13-40-53-441.jpg (Attachment deleted)

Title: Re: Autothrottle - cruise
Post by Ian Bowden on May 1st, 2019 at 9:19am
I've tried the open/close throttle route and the problem still persists, I have also adjusted the null zone of my throttle also to no avail...edit - just disabled all of my physical controllers and the issue is still there, constantly 'seeking' up and down. I'll fly the PW later and see if the issue is the same...

Title: Re: Autothrottle - cruise
Post by Ian Bowden on May 1st, 2019 at 12:00pm
Problem solved - of a fashion. It seems the cause was the effects/turbulence settings in EZDOK 3. Turned the turbulence off and the problem has gone...

Title: Re: Autothrottle - cruise
Post by Captain Sim on May 1st, 2019 at 2:12pm

Ian Bowden wrote on May 1st, 2019 at 12:00pm:
Problem solved - of a fashion. It seems the cause was the effects/turbulence settings in EZDOK 3. Turned the turbulence off and the problem has gone...

Great, thanks for sharing.

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