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Richard McDonald Woods

Reverse thrust settings for B744/748 and 77W

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I have been confused over what settings should be set for consistent operation of thrust reversers.

Is it true that I should have the following options?

  • Thrust decrease quickly set to continuous
  • Thrust reduce quickly set to none for no repetition
  • A/T MANUAL OVERRIDE set to <NEVER
  • A/T FLARE IDLE OVERRIDE set to <NO
  • HIGH IDLE ON FLARE set to <OFF

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Richard, I'm not sure I understand your problem with reverse thrust.  I'm also not sure what the first two bullets are from, are these PMDG options?

As for A/T manual override, I always set this to HOLD or ARM only.... never never.  Also, the high idle on flare kept on is more realistic and this is how the aircraft actually behaves.  Neither of these settings cause reverse thrust problems for me.

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Dan the first two bullet points are part of the sim settings regarding key presses.

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Richard

I have throttle decrease quickly set with slider in the middle (continuous, in my experience, deploys full reverse as soon as you touch the button, which is undesirable), A/T manual override set to HOLD only (so that I can easily reject a takeoff if required by just closing my thrust levers) and flare idle set to yes so that I can control the flare just as in the real aircraft.

I also have a throttle cut button set up on my thrust levers, which allows me to stow the thrust reversers after having deployed them.

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Hi John,

Many thanks for your suggestions. It is now working again as expected.

Part of my confusion was being unable to set the throttle assignments with the controller set unthoughtfully to CH PRO PEDALS USB instead of 'SAITEK X52 Pro Flight Control System'😌

My bad!

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I cant opine to most of those with confidence, but I do feel comfortable chiming in on the A/T Manual Override setting. I use the standard Saitek throttle quadrant, which was perfect for the 777, but obviously not so great now with the 747 line. I'm curious what people have to say on the high idle flare setting though.

My major problem on reversers: for me, it's all or nothing. I will open the reversers at touchdown with no thrust and not have any problem. But I still haven't mastered a way to use gradual reverse thrust. Holding down F2 or progressively pressing the button always seem to take it to full reverse thrust no matter how delicate I try. Anyone have a good suggestion? 

 

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Hi William

From Capt Joe's YouTube video, I gather that there is only idle reverse and full reverse thrust settings.

What think you?

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The suggestion is to keep the repetition slider for the decrease throttle setting in the middle - this will allow you to select the reverse thrust setting you want.

That said, the 747 operator I’m most familiar with encourages pilots either to just select idle or selct full reverse and not to bother finding an intermediary position.

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Interesting rondon. Thanks for the insight. 

I think this issue bothers me because my deceleration always seems to be much faster than reality. This kind of went hand-in-hand with the longstanding friction coefficient issue. But ever since PMDG mitigated this issue, my taxis on idle after a small touch of throttle REALLY seemed to make the entire experience take a big step forward. Ever since, I've wanted to fix this landing decel issue too (which isn't exactly a friction issue, but you hopefully get my drift).

 

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5 hours ago, wde12 said:

I think this issue bothers me because my deceleration always seems to be much faster than reality.

This is true.  During 748 beta, both RSR and I spent a week trying to ensure autobraking was providing realistic deceleration rates because I was reporting short field performance at some pretty hefty weights.  It turns out that reverse thrust in the simulator is unrealistic, especially in how it fails to decrease in effect with slower speed.  Reverse thrust is most effective at landing speeds and falls off below 100 kts but in the simulator this decrease does not happen.  Of course, autobraking is supposed to accommodate reverse thrust because it is using only as much brake as required to achieve a certain deceleration rate, and the more reverse thrust the less braking.  However, below a certain speed the reverse thrust is actually having more of an effect that braking so the accommodation 'breaks down.'

I have found that realistic landing distances for any given set of conditions is best achieved if one does not use reverse thrust below 80 kts GS.  The proper procedure in the 777 is to use decreasing amount of reverse thrust all the way down to taxi speeds but in the simulator this cannot be done realistically.

For the interested, the PMDG 748 deceleration rates (autobraking only) vary from Boeing data by less than a few percentage points, and vary from 3.4 m/sec*sec to 1.2 m/sec*sec.

Edited by downscc

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32 minutes ago, downscc said:

I have found that realistic landing distances for any given set of conditions

This may be company specific, on touchdown full reverse thrust must be applied and then reduced from there. 🙂

Grace and Peace, 

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1 hour ago, Bluestar said:

This may be company specific, on touchdown full reverse thrust must be applied and then reduced from there. 🙂

Grace and Peace, 

I intended to mean for simulation.  I've not found a suitable way to throttle reverse, it is either all or none for me.  Others?

  • Upvote 1

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Haven’t been on the sim for a good while but I’m sure my suggestion above works. Someone might want to test it and see.

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John,

I am happy with a throttle button assigned to reverse thrust at the middle setting. It works beautifully but, of course, without graduated thrust settings.

Happy with this😊

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On 1/31/2019 at 5:47 PM, rondon9898 said:

Haven’t been on the sim for a good while but I’m sure my suggestion above works. Someone might want to test it and see.

I've only been on p3d for a few months, but can't seem to find the repetition slider I remember on FSX. Am I correct that this can only be done thru FSUIPC on P3d?

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William,

See Options>Controls>Key Assignments>Throttle (decrease quickly). If the Repeat bar is not shown, make sure that you have set the correct Controller at the top of the window.

HTH

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Thanks Richard. I saw the repeat column but yeah, no bar itself. Must be the wrong controller. It looked like the same thing imported from FSX, so when I couldn't find the actual slider, I figured I had made some basic mistake. 

Also one thing of note. I was tooling around with F2 / F3 on the 748, right after booting it up. Press and release F2 and the reversers open, idle. Then quick presses to F2 and it would incrementally increase. I had tried this before when attempting to fix this issue. On landing, I would disconnect A/T before touchdown and ensure my actual Saitek throttles were idled. But during the rollout, for whatever reason, I could not get the same behavior. It would revert to the problems discussed above. I know that's not helpful, but I always found that strange. Plane is idle, and the reverse thrust works as I hope, but when actually landing, nope. 

I have yet to try the halfway repeater bar above, looking forward to seeing if it works. 

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