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rsrandazzo

PMDG 777: How realistic will it be?

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Captains-

 

As many of you know- I continually chafe at the effusive use of such terms as "best ever" or "most detailed" or "tested by a real pilot" that our little cottage industry has made so famous in product marketing. I also tend to snicker (politely, but still a snicker!) a bit at the confusion that exists between visual quality and simulation quality... (Just 'cuz it looks pretty doesn't make it good...)

 

Of course- my own snarkiness tends to leave me very little wiggle room when it comes to marketing our own products. I guess that is the price we pay being for opinionated. :P

 

When it comes to marketing our products, you have heard me say two things many times during the past fifteen years: "We make the kinds of products we like to purchase and fly" and "we want our product quality to speak for itself."

 

To put it another way: We don't want to tell you that X or Y or Z is the best you have ever seen. Instead, we want you to experience it and say same yourself. If this happens then we have succeeded!

 

A few folks have been asking "just how detailed will the 777 be?"

 

Here are some examples fleshing out some details from my earlier post:

 

The outboard ailerons on the 777 are fly-by-wire roll controls. On the actual airplane, they change their pitch position based on a number of factors such as "what mode is the FBW system in?" and "what is the current flap position?"

 

We have all of the possible positions modeled, **INCLUDING** the transition times that it takes to move them between positions. (They don't just jump from on position to another, after all!) If you happen to be watching the position indicator on the Flight Control display (or watching the wing of the external model) during one of these transitions, you will see the aileron move fluidly and progressively to the new configuration position. The speed at which they move varies depending upon the type of configuration change being made- and all of it is visible to you...

 

The outboard ailerons also lock out, much like on the 747, except that the lockout logic on the 777 is a bit more fuzzy. There are a combination of factors such as altitude and aircraft speed in KIAS, and the amount of outboard aileron displacement that is available changes as you move through these transition zones. The graph that describes the transition zone is a complex one, and the slope of the line occasionally is vertical (read: infinity) which is problematic when developing an algorithm, so we have had to develop a mathematical process to handle this continual computation in order to be certain you are only getting as much outboard aileron as you should.

 

(The process is known is numerical diffusion, for those interested... we had to smear the vertical profiles when mapping them to discrete points in order to ensure the computer could properly compute the results... Yes... This is the level of detail we seek.... :rolleyes: )

 

Now- similar logic was applied to the inboard flaperons, and these particular flight controls are constantly adjusting their angle and offset as the airplane configuration changes. Our flight control model will also move them through the correct (and sometimes very abrupt) position changes required if the aircraft is operating in the secondary or direct mode of the FBW system...

 

Continuing in the realm of flight controls for a moment: The spoilers on this airplane are fly-by-wire. (Excepting spoilers 4 and 11 which are mechanically linked and controlled) This means that they have a slightly more dynamic operating mode than many of the traditional Boeing birds. We have modeled the flight and ground modes, in addition to the various behavior changes that come when the FBW system moves out of the normal mode... as you'd expect.

 

We have also modeled an accurate spoiler mixer behavior, as we did with the NGX. On top of ALL of this, we have modeled a movement kinetic system that allows us to model not only the movement of the spoiler flight control panels, but also the rate of change in speed as they start and stop their motion.

 

This combination gives a highly realistic looking behavior for all of the flight controls on the airplane- and results in a much nicer flight control response both in look and in feel...

 

There are other details that are far more subtle. For example, since the flight controls are fly-by-wire, the flight control system can provide much greater control over the motion ranges in different phases of flight.

 

This means that a particular flight control will move 33 degrees TEU (Trailing Edge Up) and 28 degrees TED (Trailing Edge Down) during a flight control check on the ground- but if you were to attempt to move that flight control through the entire range of motion while in flight, you would find (through the haze induced by excessive pos/neg G forces!) that this same flight control only moves 30 degrees TEU to 25 degrees TED... At higher speeds, this motion range diminishes even more...

 

These little subtle details are modeled and you can see them on the Flight Control (FCTL) display, as well as on the model itself.

 

Do any of these things make the airplane harder to fly- or require you to study 3,000 pages of manuals in order to fly the airplane? No..

 

In fact- our effort to simulate the entire airplane in such detail means that it is easier to operate and the airplane responds more realistically to your inputs than would otherwise be possible- even if you don't know that all of these things are going on- when you see the simulation in operation it will look right... when you fly the airplane yourself it will feel right...

 

This is what we are driving for with our modern line of products- and I'm quite happy with how it is progressing on the 777!


Robert S. Randazzo coolcap.gif

PLEASE NOTE THAT PMDG HAS DEPARTED AVSIM

You can find us at:  http://forum.pmdg.com

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Wow, that's pretty impressive.


-----------------------------------------------------------------------------

Dana Palmer

KJAC

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Sounds amazing!

 

Appreciate you taking time from your Christmas to write this - thank you!

 

Could you not throw in at least one screenshot for Christmas? Please? Cheery on top?

 

)-:

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This sounds fantastic. The little things really come together and make these sims special.

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Wow that sounds like a lot of detail and a lot of work. Thanks for sharing. Just out of curiousity, does the 777 have the same types of customer options like the 737 does in regards to items such as all the display configurations?

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So that's why you guys take so long. I thought you guys just sat around working for 5 minutes and spent the rest of the time laughing at us. :lol:

 

The 777 is sounding better and better. Keep up the good work.

 

Wow that sounds like a lot of detail and a lot of work. Thanks for sharing. Just out of curiousity, does the 777 have the same types of customer options like the 737 does in regards to items such as all the display configurations?

 

The reason that Boeing came up with the PFD/ND and EFIS/MAP displays is so that the costs/time spent training pilots on both the classic 737 and 737NG coule be lower.

 

The 777 doesn't have the EFIS/MAP displays. Though I'm sure the 777 has things such as the landing altitude bar, rising runway, and AOA dial.


Kenny Lee
"Keep climbing"
pmdg_trijet.jpg

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Sounds like she'll have everything except a fully stocked mini bar and a toilet. Looking forward to it and greatly appreciate all the info n' updates RSR.


Chris Sunseri

 

 

 

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But, does it have the cup holders modeled correctly? On the captains side panel, they must be removable, easily cleaned, hold an airline standard coffee cup and soda can. The nice MCE crew lady brings us many drinks (too many sometimes like right now ;)). If we use it too much then we should be forced to use the simulated lavatory.

 

Thanks for the update and Merry Christmas :)


 

 

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It's very understandable that these should be modeled correctly. It's a tendency that many of us have to model absolutely correctly and fully. Considering the complexity of algorithms and implementation, take your time. As a EE , I fully understand what takes time. So take your time.

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This is the level of detail I really admire and appreciate. It is an even greater feat when the product is considerably performance-friendly, which PMDG has demonstrated in the past.

 

Systems-wise, I do not think any of us have concerns about the PMDG B777. Based on my largely positive experience with the PMDG B747, one minor visual improvement I really hope to see in the PMDG B777 is an improved landing gear animation. I find softly lowering the entire rear gear of any wide-bodied aircraft, whether an A330 or a B747, to be challenging but satisfying when done properly. I am really hoping that the gear of the PMDG B777 will un-tilt after touchdown in a manner more faithful to the real aircraft (i.e., difficult not to let it slam to the ground) instead of relating directly to the pitch of the aircraft, as seen with the gear of the PMDG B747.

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