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engwerda

Can you fly the MD11?

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Will the MD 11 fly like its real world counterpart? Apparently it is very "squirrely" on approach and requires a lot of pilot input because of basic design problems that have to do with the empenage and the aft C of G.One experienced MD 11 plot had this to say;"The MD-11 is not fly-by-wire. It is, however, fly by CONSTANT pilot input. The geniuses at MD decided to make the empennage 40% smaller than the DC-10 to save on both parasitic drag and induced drag by keeping the c.g.[center of gravity] near the aft limit during high-speed cruise.This airplane doesn't really have a "slot" when you are on final; it doesn't seem to really stay at a trimmed AOA [angle of attack] /deck angle at a specific power setting/airspeed. As such, the pilot is constantly making little corrections, like flying a dynamically unstable fly-by-wire fighter with the computer out. This is unlike any transport aircraft I've flown. Part of the problem is a system called the Longitudinal Stability Augmentation System (LSAS) which is a computer that constantly trims the stab to make up for the shortcomings of the tail size. The landing is also unique. As soon as the plane touches down I have to push on the yoke to counteract a severe pitchup from the spoilers coming to 2/3 extension. Less than a second later, the autobrakes kick in, so you have to pull back on the yoke to gently lower the nose to the runway.Somebody once said they should let Lockheed design all the airplanes, Boeing build them...and McDonnell-Douglas market them! And let the French guys stick to making Citroens and Peugeots..."Too much for the evarage flight simmer do you think? Or will it be made more "Flyable" by PMDG?Gerry

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Guest Basten_TFF754

>The landing is also unique. As soon as the>plane touches down I have to push on the yoke to counteract a>severe pitchup from the spoilers coming to 2/3 extension. Less>than a second later, the autobrakes kick in, so you have to>pull back on the yoke to gently lower the nose to the runway.In a software update of the LSAS system this has been "corrected" meaning that the action still has to be done but its now taken care of by the LSAS system.I think that these things make the MD-11 a special plane! :-)______________________________Basten HeidemaProud MD11 AddictFLY DC JETS!

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Cool, reminds me of the 727 where the cure for excessive sink over the numbers was a PUSH on the yoke- seemingly wrong, but because of the rearward wing location and T-Tail, it worked well. Of course, you had to then PULL to hold the nose off for aerodynamic braking, and then smoothly lower the nose while you still had elevator authority- made for an interesting few seconds!Tabs, Marcus or others, will there be a way to disable the LSAS to experiment with "true aerodynamic behaviors"? Is their a "failure" module for the LSAS that would allow this? Despite being a Boeing devotee, this is why I am excited about PMDG's MD-11- totally new systems and procedures. Wonderful stuff IMHO- especially at the level of detail that PMDG will push out! Can't wait (ok, maybe I can :)!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png


Best-

Carl Avari-Cooper

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If you have the MartinAir MD-11 video from ITVV you will notice that the captain is VERY active with the yoke on the approach! I really can't recall any other video where the movement of the yoke has been that intense, but of course many factors play in - use of AP, weather conditions etc. Or perhaps I really heaven't thought about it so much before and it isn't worse! :)


Krister Lindén
EFMA, Finland
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>Tabs, Marcus or others, will there be a way to disable the>LSAS to experiment with "true aerodynamic behaviors"? Is>their a "failure" module for the LSAS that would allow this? Much simpler, there are switches on the overhead panel from which you can turn off all LSAS channels.


Michael Frantzeskakis
Precision Manuals Development Group
http://www.precisionmanuals.com


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>If you have the MartinAir MD-11 video from ITVV you will>notice that the captain is VERY active with the yoke on the>approach!Krister,Check again, you'll also notice LOTS of aileron input too. Those big and constant corrections are caused by gusty winds there, the MD-11 doesn't fly THAT bad... ;)Regards,Markus


Markus Burkhard

 

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Gerry, Carl,for sure we'll try to model all of the characteristic flight behaviours of the MD-11, pushing the yoke on touchdown, the Roll CWS, LSAS trimming, heck maybe even the shaking of the airplane when on final with flaps at 50


Markus Burkhard

 

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Marcus and Michael:Many thanks for the insight. I continue to salivate at the prospect of getting my hands on this bird. I was sobered at the comments about flight dynamics programing, I was hoping it was a bit further along than is now seems to be. Still, good things come to he who waits.......Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png


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Carl Avari-Cooper

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Guest D17S

For the 11 and the -400, it'd be fun to have that "Brakes-set @ TO Power Shaking-Goin'-On" modeled. You pilots don't get this much, but we mx dogs really get to shake things up on our high power runs. We'll go out and blast away at TO power for several minutes with the brakes set. In both the 747 (-1/200s anyway) and the 11, push 'em up to TO. Gotta get your fun where you can. It's quite a ride."Hey, someone keep an eye out the window. These things do tend to skid!" (ahhh, just a bit though)I had a 767 out on the runway the other day for a Mx run. Brakes set at the departure end of a 10,000 foot runway. TO power, bouncing away. Just for fun, while I was waiting for the folks back at the gate, I had programmed an outbound SID and my favorite Sadde 6 arrival. (I'm not supposed to know how to do this. It's all your fault.) Out on the runway, just sitting there at TO power, I reached up and poked LNAV/VNAV. They lite right up. I'm toein' the brakes. All I need to do is get to 50 feet and poke the AP button. The rest I know by heart. You guys are gonna get me in trouble. And that yoke push to get the nose down on rollout. That's for real. We had an MD11 in the barn for a month fixing a nose gear a crew put down a bit too hard. I flew the MD11 sim and crashed that way too. Let's have that for sure!And don't forget, I want to put that thing on its tail with an "offschedule" fuel transfer. The systems automation in the MD is much more integrated than in the 744. It is a more complicated airplane. The AFS has an entirely different (and MUCH more rational) philosophy. It's a better system and I want to show my pals why - in flight! Take your time. I imagine even y'all didn't fully realize what this was gonna be. Stay at it. To do this right is a Very big job. You have our support.

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Guest Dave65

I cant wait,I will be a great challenge to try and develope the skills to fly it.

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