Disabling Fly By Wire?

[mrvoyager 0]

Because they think it is wrongly simulated but aren't able to fully read and more important understand the included manuals. That's why, it's scaring me Kyle is going to morph into a carebear himself. 

Sorry, some of us cannot afford those awesome manuals and too much screen reading gives me headaches, so I go with the tutorials and soon with the help of fs2crew

 

By the way it seems PMDG ran out of copies for every manual or my browser is not working well.

[flightwatch 68]

I know but I was just pointing out my opinion that there is something off with the autotrim, which I guess will be fixed, where I notice that its slightly unprecise and slow and also the manual trimming (with the joystick buttons) feel too jerky so one has to be taping it and still the plane changes too much so its difficult to establish a stable pitch specially when chaging, so overall I find this 777 a little hard to handfly. Even thou the NGX has no autotrim I feel its much easier to fly even thou it responds quicker to yoke movement. Just an opinion, but obviously this wont be noticed much when taking off or when doing an autoland, but me I like to just handfly sometimes.

 

If anything, the auto-trim works too well, and too quickly.  It has been my experience that it stays where you point it without variance.  If I want to command 5° nose up, I pull back until I see 5°, let go, and it stays there.  Is this realistic behavior?  I don't know...I'm a 737 guy, but it doesn't seem exactly realistic as there are always physical elements counteracting the command (wx, momentum, gravity, etc.)  Regardless, Ryan has already stated that it has been rewritten for sp1, so let's see how that works before tying anybody to the stake.

[mrvoyager 0]

The 777 does not have a manual backup, the FBW system is always active. You can turn the protections and stuff off by turning off the primary flight computers on the overhead but that's not going to make it fly like a 737NG.

 

Just wait for SP1 - it handles much more like a normal airplane. Everything about it is changed and rebuilt from scratch.

I am now wondering if there is a different key to use the elevator trim bar as opposed to the yoke buttons since the bar has a smoother and constant movement so it would be better, I would like to assign the trim to the bar but I am guessing it cannot be done.

 

P.S. I just found out it can be done but it has to be an axis right? :(

 

P.P.S. I just found how to make it better by adjusting the repeat slider 

[gnomegemini 7]

Sorry, some of us cannot afford those awesome manuals and too much screen reading gives me headaches, so I go with the tutorials and soon with the help of fs2crew

 

By the way it seems PMDG ran out of copies for every manual or my browser is not working well.

 

Just watch into the pmdg operations manager, select 777 and click manuals. You can afford the money to read them because you've paid them already.  ^_^

 

Does this mean I would be more or less cuddly?   :wub:

 

 

Dear... YES. It really improves your cuteness :-D

[mrvoyager 0]

If anything, the auto-trim works too well, and too quickly.  It has been my experience that it stays where you point it without variance.  If I want to command 5° nose up, I pull back until I see 5°, let go, and it stays there.  Is this realistic behavior?  I don't know...I'm a 737 guy, but it doesn't seem exactly realistic as there are always physical elements counteracting the command (wx, momentum, gravity, etc.)  Regardless, Ryan has already stated that it has been rewritten for sp1, so let's see how that works before tying anybody to the stake.

I'm a 737 guy too and cannot understand it because I know the 777 is better but it just doesn't feel as great to fly, but I think its just because of how they are made in real life and nothing to do with the sim.

 

Just watch into the pmdg operations manager, select 777 and click manuals. You can afford the money to read them because you've paid them already.  ^_^

 

 

Dear... YES. It really improves your cuteness :-D

 

I know I have the pdf's but I just can't read much from a screen, gives me headaches. Wish I had a few of the printed manuals, would read the whole thing .... maybe one day, I can dream

[Tabs 2,790]

If anything, the auto-trim works too well, and too quickly.  It has been my experience that it stays where you point it without variance.  If I want to command 5° nose up, I pull back until I see 5°, let go, and it stays there.  Is this realistic behavior?  I don't know...I'm a 737 guy, but it doesn't seem exactly realistic as there are always physical elements counteracting the command (wx, momentum, gravity, etc.)  Regardless, Ryan has already stated that it has been rewritten for sp1, so let's see how that works before tying anybody to the stake.

 

No, it was not correct in the RTM version. In SP1, if airspeed changes, you will need to trim manually unless on autopilot - period. The system will pitch the airplane back toward the previous trim reference speed. There's a very detailed writeup of how the system works in the SP1 Supplement that's at the end of the revised Introduction manual.

[thebigblue88 0]

If you want to disconnect the Fly-By-Wire you can try moving the primary flight computer switch to DISCONNECT (the switch is next to the TAC) now it will effectively fly like a 737. You will lose a lot of features but it will now fly like a more conventional aircraft.

The B777 Fly-By-Wire (FBW) system introduces some very new concepts to the art of flying while maintaining the traditional look, and to some extent the feel, of that experience. The B777 Pitch Trim System is unique in the commercial world and if used as intended will not only enhance the pilot’s enjoyment of this remarkable airplane but also reduce his or her workload. Some of the differences from conventional trim systems are not fully understood and the purpose of this paper is to expand on this important area.

 

Throughout this paper it is assumed that the FBW system is operating in the Normal mode and that the pilot is flying manually.

 

The main concept to grasp right from the start is that the pilot only needs to TRIM FOR SPEED CHANGES. Performing maneuvers at constant speed does not call for further change. Once trimmed for a speed, say a 250 kt departure, you can level off, climb, turn, and level off again without ever touching the trim switches. During a Go-around maneuver (which should be flown at a constant speed of Vref + 5 kts) there should be no need to re-trim; perform the maneuver by adjusting the pitch and when flying away at (the same) ‘bug speed’ the aircraft will still be trimmed for this condition. Engine out work makes no change to this concept!

Similarly, on takeoff the Pitch Trim System follows the actual speed until stabilized. This means that if the pilot’s rotation is correct, stabilizing between V2 + 15 and V2 + 25 kts for two engines (or V2 and V2 + 15 kts for single engine); there is no need to trim until you change speed at flap retraction.

 

The Pitch Trim System trims at a constant 10 kts per second throughout the flight speed range, unless utilizing the ‘blip’ to trim function when nearly trimmed. Remember from your basic flight training the idea of “Put the aircraft where you want it, then trim out the residual forces?’ Well, it works just as well in the B777 as it did in the light trainer aircraft. If you find yourself flying through the trimmer or constantly ‘blipping’ to find the trimmed condition then you are misusing the system. It is quite possible to put the aircraft directly in trim at a first attempt without using the ‘blip’ facility.

 

The ‘blip’ facility is a difficult one to grasp, especially since there is no direct readout of Trim Reference Speed (TRS) or the 5 kt speed range band. Once the TRS is within 5 kts of ACTUAL speed a ‘blip’ will synchronize the TRS to ACTUAL speed. The ‘blip’ facility cannot sync to bug speed, unless actual and bug speed are co-incidental (again, put the aircraft where you want it, then trim out residual forces). The question is: How do you know when you’re within the 5 kt band? Well, you don’t precisely and this is where some confusion arises. Usually if you feel the aircraft is ‘almost’ in trim then you’ll be within ‘blip’ range. If not, a ‘blip’ will only move the TRS at the 10 kt per second rate, i.e., perhaps 1, 2, or 3 kts. This may or may not be enough to put the aircraft in trim; since if the 1, 2, or 3 kt move puts the TRS within 5 kts of actual speed the system will sync for you. If not then you have only moved the TRS a few kts towards the trimmed condition.

 

By way of example: Previous trimmed speed 180 kts, now flying at 160 kts – It is possible to bring the aircraft back into trim with a 2 second trim input. If however, at first attempt, you achieved say 168 kts TRS a ‘blip’ might only put the TRS to 166 kts, i.e., still not in trim. More likely you might have achieved a TRS of 164 kts at first attempt, and then the next ‘blip’ would sync the trim system.

 

Another important idea to grasp is that once trimmed for speed you should avoid ‘blipping’ the trim switches. At best you will achieve nothing, but you could actually put the aircraft out of trim. Since the TRS moves at a constant 10 kts per second, as mentioned above, the ‘blip’ you give to a trimmed aircraft moves the TRS away from the trimmed condition by ‘a few’ kts. If the TRS remains within 5 kts then the system will re-sync, however if your ‘blip’ was greater than ½ second the aircraft will then be out of trim. This is often observed on final approach, when pilots exacerbate speed and glideslope conflicts.

[martin-w 3,235]

Esbops, on 08 Jul 2014 - 6:19 PM, said:

 

 

As far as I understood from this message that the flight model implemented in 777-200LR and F versions is not as realistic as we have been thinking or expriencing. Do you intend to say this?

 

 

 

 

Correct. This has already been stated multiple times by the team here on the forum.

 

 

 

And by a dedicated few, myself included, prior to the team or anyone else realising it..

 

Thus, we deserve the ER free of charge as a thank you for being the catalyst for changes that render the PMDG 777 post SP1, the greatest add-on ever released.

 

:whistle:

[~Craig~ 10]

 

 

I just can't, for the life of me, understand why people would spend close to $100 on a realistic simulation and want to change things to make it unrealistic.

 

Well the real aircraft does not autotrim whatsoever, and the PMDG777 autotrim's incessantly, so that renders your entire point above, moot.

[g_precentralis 191]

...

What's a "blip"?

[martin-w 3,235]

Well the real aircraft does not autotrim whatsoever, and the PMDG777 autotrim's incessantly, so that renders your entire point above, moot.

 

Actually that's not strictly true.

 

The real T7 autotrims for configuration changes, like flap deployment for example.

 

What it doesn't do, that the PMDG T7 does at the moment, is trim for speed changes.

 

Rob, a real world 777 pilot on this forum, has commented that trimming the T7 should feel no different to trimming any airliner.

[flightwatch 68]

Well the real aircraft does not autotrim whatsoever, and the PMDG777 autotrim's incessantly, so that renders your entire point above, moot.

 

Actually, my friend, it does autotrim...just not for speed. My point was in reference to somebody wanting to completely shut off the 777 FBW system in order to make it fly more like a 737.  So, before being quite rude and blasting somebodies post as moot, I suggest you read it in the context that it was written in instead of assuming and reading it in the context that you have in your head.

[gnomegemini 7]

The real aircraft autotrims in few circumstances. If you fly straight and extend flaps it shoult trim to maintain flight vector.

[martin-w 3,235]

We've already said that...

[Driverab330 74]

First of all the FBW on the 777 cannot be shut down by pushing any buttons in the cockpit. There are two mechanical back up on this airplane which is spoiler 4, 11 linked to the yoke and the vertical stabilizer trim linked to the ALTN trim know located on the left hand side of the Thrust levers. So in the event of a complete electrical power lose, that's the only non-FBW mean of controlling the airplane. Which is quite similar to the A330/340.

 

Switching the Pri Flt computer off only disc the PFC from the FBW control system and basically means all control input will now command the control surfaces directly via ACE computer without having to go through the PFC. This is what we call the "direct law" which in simple terms, we can see it as a direct relationship between the yoke and the aileron.

 

Having flown both the airbus and the 777, the 777 in A/T mode with constant speed it flies no different than the airbus most of the time. The only minor differences is for some old 777 airplane with a slightly bended air frame some aileron/rudder trim is required to fly straight and level just like a conventional airplane.

 

The trimming of the current PMDG T7 is not right as many people had mentioned already. Which makes it slightly harder to fly.

 

Another problem is every time after doing touch and go with the airplane, the trim is all over the place to the extreme that I simply switch on the AP to reset the trim on downwind then disconnect it to fly the rest of the circuit. I wish the SP1 will correct that as well. Because what I normally do with the 777 in flight sim is a simple 1500' circuits.

 

Another thing is the aerodynamic model of the airplane, at 230 Tons I had to pitch up from 6deg to 10~11deg for a normal 20-25 deg AOB level turn with flap 5 around 180kts, normally on a real airplane is usually less that 7.5deg mark.

 

The other thing I found is the yaw damper does take a while to correct the slip both in and out if the turn. It's very noticeable when doing visual or circling approaches which requires and relatively quick maneuver compared to a normal ILS straight in approaches.

 

These are the two issues I experienced and I hope it will be corrected in the up coming SP1. Otherwise I am very happy with the product, and I am sure a lot of work behind the scene had been put in to make this 777 add on possible. So to the PMDG team, I really appreciate what you guys have done so far, and keep up with the good work.

 

Cheers.