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kmanning

Auto-Pilot is NOT Engaging

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 I’ve had the force feedback 2 joystick as well. And I see exactly what is happening. He has disconnected the power cord that provides the force feedback and resistance to the joystick. So now the joystick will freely move and flop around without any resistance. He will never get the auto pilot to engage because he cannot find the center with any reliability.  There is no return to center at all. 

 If you want to continue to use the joystick you should invest in FS force. It’s a fantastic program and combined with the joystick the experience in the Sim is really nice. I’m actually considering going back to the joystick because it is that enjoyable. 

Edited by MattS

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10 hours ago, pete_auau said:

if  you had  disconnected  your  joystick  from  the  pc  and  still have  the  issue  than  its  not your joystick  than

No, it's not the joystick and I didn't think it would be. The problem was most likely because I didn't have the airplane trimmed correctly. At first, I've always had the impression that once you set the take-off trim, it would take care of all phases of the flight, but it doesn't. When you think about it, the auto-pilot has not even been engaged for it to take control of the trimming. So, immediately after lift-off, you have to trim the airplane so that you're not having to keep constant pressure on the yoke. In the PMDG 747-400, I could engage the auto-pilot but it kept disengaging, most likely because I didn't have the plane trimmed correctly. But I was able to engage it, only for a few seconds. I did get a yellow message, and I think it said something to the effect that it required action from me.

Ken.

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10 hours ago, JRBarrett said:

I don’t think he disconnected his joystick completely - just the wiring that provides the return-to center function.

That's correct. The USB that provides axis control was always connected.

Ken.

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14 hours ago, skelsey said:

Hi Ken,

I wrote a piece about trimming here which you may find useful if you had not seen it:

In short: even with a GA aircraft, a centering force to pull/push against is essential and not so very far removed, really, from real life. As has been mentioned, as far as airliners are concerned actually the control column will almost invariably be centred when the aircraft is in trim because the whole horizontal stabiliser moves and therefore when the aircraft is in trim the elevator will be in the neutral position: i.e. with the control column centred.

Even in a light aircraft equipped with trim tabs, the principle is much the same; hold the attitude and trim off the force you are exerting. If you do not have any centreing force then you will have no feel at all.

Saying that, although I don't have a force feedback stick myself, are you aware of FSForce? I gather this replaces the default FS force feedback with a a much more realistic feel so may be worth looking at.

Regarding hardware -- I have the Saitek Cessna yoke myself and I find it very good for the money - the springs are solid enough to mean you really do feel it when the aircraft is out of trim -- stalling a light aircraft, for instance, requires a fairly hefty haul to the backstop (or I'm just weedy!). Personally I find the yoke provides excellent control for light aircraft and airliners (although I still prefer my old Sidewinder Pro 2 for the Airbus -- the slightly different flight control system and fly by wire implementation makes the stick a little more intuitive in that setting).

Re: sensitivity - always ensure that the sensitivity sliders in FS are set to maximum, because all they really do is limit the maximum input and/or introduce a lag in inputs, neither of which are much fun! It's also worth looking at FSUIPC if you don't already own a registered copy -- this provides the capability to adjust control response curves etc which can be quite useful.

Thanks Simon, I'll look into that FSForce. But are the forces realistic? I keep my force feedback turned off in the sim because the feedback forces are over exaggerated and are not realistic, and just aggravates my flight. 

Ken.

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Hi all,

In the actual 737NGX, you turn the yoke either fully left or right and you let go of it, does it actually return to center?

Ken.

Edited by kmanning

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41 minutes ago, kmanning said:

Hi all,

In the actual 737NGX, you turn the yoke either fully left or right and you let go of it, does it actually return to center?

Ken.

Your question somewhat depends on if you are in flight or on the ground.

In flight the aerodynamic loads will center the roll axis. Of course. On the ground I have to assume the roll axis will also center because I'm not type rated... but in all the aircraft I've flown yes.. the roll axis is self centering on the ground.  It's not as if it is spring loaded but each aileron is balanced to return to a neutral position.

The poor man's gust lock is to pull the yoke back (nose up) and rotate full aileron and then thread the seatbelt through the yoke and secure it.

Edited by downscc

Dan Downs KCRP

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2 hours ago, downscc said:

Your question somewhat depends on if you are in flight or on the ground.

In flight the aerodynamic loads will center the roll axis. Of course. On the ground I have to assume the roll axis will also center because I'm not type rated... but in all the aircraft I've flown yes.. the roll axis is self centering on the ground.  It's not as if it is spring loaded but each aileron is balanced to return to a neutral position.

The poor man's gust lock is to pull the yoke back (nose up) and rotate full aileron and then thread the seatbelt through the yoke and secure it.

That would be on the ground and not in flight. In flight, you would have aerodynamic forces that would effect what the yoke does. The planes I've flown, if I turn it fully left or right, It does not spring back, or snap back to the exact center like a joystick would. It may move a little but usually stays where I left it for the most part. The weight of the elevator surface, of course, will usually make the yoke return if you pull it back fully, but it doesn't return to a center position, or spring back like a joystick. But regardless, when you move the control wheel on the ground, say while taxing, there is no return to center force. It moves freely until you get into flight, then you have the aerodynamic forces working on the control surfaces. I don't know who they are, but did someone say we have real world 737NGX pilots in the forum? They would surely know. I have a friend who flies a small commercial private jet, but I'm not sure if there's any comparison.

Ken.

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There's a lot of confusion on topics here, to be honest, and I'd argue that some confusion is being added back in to (subconsciously or not) defend the mind's existing framework of how it "should" be.

TO Trim is great. It gets you off of the runway. At about 1" AGL it's worthless, as it is a planned value. Re-trim the plane so that you can let go of the yoke (where the physical yoke resets itself to is irrelevant) - if the plane drifts away from where you wanted it to go when you were last holding the yoke, you're not in trim.

The main issue at hand, though, is the plane isn't being passed to the AP in trim. AP kicks off because it's out of trim.

We can continue for another 4 pages about the aerodynamics behind it, or we can give you a solution:

  1. Dispense with your old idea of what "in trim" is and listen to the multiple pilots trying to explain it to you; or
  2. Turn off realistic AP engagement, and turn on the setting to ignore your hardware with the AP on.

Kyle Rodgers

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1 hour ago, kmanning said:

That would be on the ground and not in flight. In flight, you would have aerodynamic forces that would effect what the yoke does. The planes I've flown, if I turn it fully left or right, It does not spring back, or snap back to the exact center like a joystick would. It may move a little but usually stays where I left it for the most part. The weight of the elevator surface, of course, will usually make the yoke return if you pull it back fully, but it doesn't return to a center position, or spring back like a joystick. But regardless, when you move the control wheel on the ground, say while taxing, there is no return to center force. It moves freely until you get into flight, then you have the aerodynamic forces working on the control surfaces. I don't know who they are, but did someone say we have real world 737NGX pilots in the forum? They would surely know. I have a friend who flies a small commercial private jet, but I'm not sure if there's any comparison.

Ken.

The 737 is a bit different than other Boeing aircraft in that the ailerons and elevators have mechanical reversion. They can be moved with no hydraulic power applied. The 737 elevators and ailerons are “mechanically actuated and hydraulically boosted”. It is similar to an automobile with power steering and brakes. If the engine quits while driving, you can still steer and brake, but it requires much more effort - (especially in steering).

Gulfstream aircraft up through the G-550 work in a similar way.

But the bigger Boeing aircraft like the 747/757/767 use exclusively hydraulic flight controls. Without hydraulic power, the flight controls cannot be moved, and neither can the yoke. If you sit in the cockpit of such an aircraft that is unpowered, you will find that the yoke is rigidly locked in both pitch and roll. In fact if you tried to force the yoke to move in either axis, you would likely cause damage to flight control linkages or the artificial feel units.

Even small to mid-sized jet aircraft which use fully hydraulic flight controls work in the same way. The two aircraft I maintain on a daily basis - The Dassault Falcon 900 and Bombardier CRJ-200 are exactly the same in this regard.

In answer to your question: If an aircraft uses hydraulically actuated flight controls, and the aircraft hydraulics are powered on the ground, when the yoke is moved in either pitch or roll, and released, it will return to center. The centering force comes primarily from the pitch and roll artificial feel systems.

It is nothing like a Cessna or Piper where you can roll the yoke fully left or right on the ground, let go and have it remain in that position.

The 737, having flight controls that are somewhat of a mechanical and hydraulic hybrid, it may be possible to do so. I would have to leave that question to a 737 pilot or maintenance engineer.

 


Jim Barrett

Licensed Airframe & Powerplant Mechanic, Avionics, Electrical & Air Data Systems Specialist. Qualified on: Falcon 900, CRJ-200, Dornier 328-100, Hawker 850XP and 1000, Lear 35, 45, 55 and 60, Gulfstream IV and 550, Embraer 135, Beech Premiere and 400A, MD-80.

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4 hours ago, scandinavian13 said:

There's a lot of confusion on topics here, to be honest, and I'd argue that some confusion is being added back in to (subconsciously or not) defend the mind's existing framework of how it "should" be.

I don't see that there's any confusion here. I'm not sure if you're suggesting this, but if you're suggesting that I'm coming here to subconsciously confuse the minds of how it should be, or that I'm suggesting that it's the PMDG product, which I've never said, you're dead wrong and I resent that.

Quote

TO Trim is great. It gets you off of the runway. At about 1" AGL it's worthless, as it is a planned value. Re-trim the plane so that you can let go of the yoke (where the physical yoke resets itself to is irrelevant) - if the plane drifts away from where you wanted it to go when you were last holding the yoke, you're not in trim.

The main issue at hand, though, is the plane isn't being passed to the AP in trim. AP kicks off because it's out of trim.

I understand that now.

Quote

We can continue for another 4 pages about the aerodynamics behind it, or we can give you a solution:

  1. Dispense with your old idea of what "in trim" is and listen to the multiple pilots trying to explain it to you; or
  2. Turn off realistic AP engagement, and turn on the setting to ignore your hardware with the AP on.

Everything that was mentioned here about trimming, I completely understand. I've flown GA planes and trimmed them in flight. But I never flown a real 737 and assumed the process to be a little different, since they use the entire horizontal stabilizer to trim. So far, my solution has been solved from what was posted here. You've mentioned that I had 3 real world pilots telling me to re-trim, and I agree with them. But you never specified as to rather they were real world 737 pilots. You also mentioned that If I've been getting lucky up to this point, then I've been getting lucky. No, it's not just me. There are many others who have not been trimming the airplane, and for some reason, they have been lucky. My brother told me that he never trimmed the airplane but the auto-pilot would always engaged, especially in FSX. It was the same with me. I never had to re-trim in FSX until I started using the P3D simulator. Since it was never mentioned in the manual to re-trim, I never used it. I was following the manual's instructions. But now I'm re-trimming and so far, I have no problems.

Ken.

Edited by kmanning

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8 hours ago, kmanning said:

I don't see that there's any confusion here. I'm not sure if you're suggesting this, but if you're suggesting that I'm coming here to subconsciously confuse the minds of how it should be, or that I'm suggesting that it's the PMDG product, which I've never said, you're dead wrong and I resent that.

It wasn't meant to imply subversiveness. I was simply alluding to the natural inclination of the mind to reject thoughts that conflict with established frameworks. It seemed that the discussion had gotten this far because there was resistance to the idea of being in trim, muddied by the inclusion of force feedback and yoke position (and position return).

Want an example? Watch the discussion that follows when you explain that the 250/10 rule isn't really as hard-line as people claim. Those who don't outright reject your notion will usually - instead of looking and saying "you know, you're right" - will add in all kinds of notes about ATC approval (in FAA land, this is not required, and specifically noted to controllers that pilots will not note or request it - 7110.65 5-7-2 Note 1), and/or drag in the concept of .117d not making specific reference to clean config, so they'd just leave flaps out.

Nothing wrong with it - simply human nature.

9 hours ago, kmanning said:

I've flown GA planes and trimmed them in flight. But I never flown a real 737 and assumed the process to be a little different, since they use the entire horizontal stabilizer to trim.

Trim is trim. The concept is the same no matter what you're flying. If anything, it's more extreme for aircraft with wider speed bands (the trimming of the entire stab has more to do with minimizing drag while remaining in-trim than it does simply to trim out forces, though effective lever arm is part of it).


Kyle Rodgers

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Ken,

I found this

When checking the elevator she holds it back to center but doesn‘t move it herself.

Edited by Ephedrin

,

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On ‎10‎/‎10‎/‎2018 at 6:37 AM, kmanning said:

No, it's not the joystick and I didn't think it would be. The problem was most likely because I didn't have the airplane trimmed correctly. At first, I've always had the impression that once you set the take-off trim, it would take care of all phases of the flight, but it doesn't. When you think about it, the auto-pilot has not even been engaged for it to take control of the trimming. So, immediately after lift-off, you have to trim the airplane so that you're not having to keep constant pressure on the yoke. In the PMDG 747-400, I could engage the auto-pilot but it kept disengaging, most likely because I didn't have the plane trimmed correctly. But I was able to engage it, only for a few seconds. I did get a yellow message, and I think it said something to the effect that it required action from me.

Ken.

well  there  one  way  to  find  out  if  it not  the  joystick  or  not  since  you  havnt  mentioned  that  you havnt  tried  my idea is  to disconnect  your  joystick completely from  your  pc  and  than  take  off  using  the  key  board   than  once  airborne   once  you got gear  up and  flaps up   connect  the  ap


I7-800k,Corsair h1101 cooler ,Asus Strix Gaming Intel Z370 S11 motherboard, Corsair 32gb ramDD4,    2  ssd 500gb 970 drive, gtx 1080ti Card,  RM850 power supply

 

Peter kelberg

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I reread Ken's very first post and did some quick test flights. I've now done a number of departures with NO trimming at all. NONE. Not before take off and not after. I have realistic engagement ON. The AP connected and stayed connected afterwards, every time, . Ken's post suggested that that is roughly how his planes used to behave (minimum trimming) and now don't. I can confirm that all of mine engage properly without having to trim after take off, just let go of the stick (spring centered) and engage AP, job done. It's not the correct way to do it but it works anyway.

So, something other than trim is causing the problem. IMO.


Bill Casey

wpigeon.jpg

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39 minutes ago, BillC said:

I reread Ken's very first post and did some quick test flights. I've now done a number of departures with NO trimming at all. NONE. Not before take off and not after. I have realistic engagement ON. The AP connected and stayed connected afterwards, every time, . Ken's post suggested that that is roughly how his planes used to behave (minimum trimming) and now don't. I can confirm that all of mine engage properly without having to trim after take off, just let go of the stick (spring centered) and engage AP, job done. It's not the correct way to do it but it works anyway.

So, something other than trim is causing the problem. IMO.

Bill -- I'm 100% certain it's the trim. To replicate what Ken's situation is, what happens if you hold the stick out of centre and then try and engage the autopilot?

That's what he's doing...

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