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pilotresponse

Strange landing behavior in strong crosswinds P3DV4

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I was wondering if anyone has had and issue with the 777 manual landings in crosswinds in excess of 30kts. In all tests I have done and confirming this with at least  2 other friends of mine who also have the 777, we have all found it impossible to land the 777 manually with winds of 35, 40, and 45 knots full crosswind, even though in autoland the aircraft manages to land. The behavior of the 777 has been the same for all of us. The aircraft lands at first but will not decelerate with spoilers armed, and reversers deployed. for all of us EICAS does not show reversers green, eventually wind vector on the EADI shows headwind even though sim says constant crosswind (displayed in red with shift Z) and airspeed suddenly increases by 10-20 knots and 777 becomes airborne again. The 3 of us have different control yokes, rudder pedals, and throttle setups, but experienced the same thing. Other sim aircraft we try do not experience this problem including pmdg 744,748 QW787 and others. Are we all missing something or is this a PMDG 777 issue. Should I open a technical ticket with PMDG as to this strange behavior on P3DV4?

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I will try to post one but if anyone has P3DV4 and can try flying to any airport that can accommodate a 777, (add on or not, doesn't make a difference) and modifies wx to a steady 35kt crosswind or greater and attempts a manual landing you should see the same strange behavior. Or at least the 3 of us did for sure. Really unrealistic behavior, at this extreme end of the  envelope, are we all missing  something?

Edited by pilotresponse

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What crosswind limitation are you referring to? 777 doesn't have a crosswind limitation that I know of, just a maximum demonstrated component of 42 knots but the real sims can be set to up to 55 knots. Autoland limit is 25kts, but the PMDG 777 will still do the autoland more or less perfectly even in 35kts plus, it's only in manual flight that this strange behavior shows up. Any thoughts?

 

Edited by pilotresponse
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FCOM L.10.1 maximum demonstrated crosswind 38 kts.  Maximum autoland crosswind is 25 kts.

Each pilot should have their own crosswind limitation based on experience. I've landed with 40 kt crosswinds real world and it is a very challenging experience that I'm not sure I'd repeat.  This is definitely at the limits of the envelope and no PC simulator does very well at the limits.

All that being said, if you believe there is an inherent limitation in the PMDG simulation then that does belong on a trouble ticket and in this case I would recommend you provide a lot of accumulated data.


Dan Downs KCRP

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Those limits are from the PMDG provided FCOM, AFM information and my FCOM says different in fact on dry runway company limitation is 45kts (real world). Yes you are right pilots should have their own limitations. I've also done it close to that in real world and agree, since all sims (from PC to big training ones) don't really do it justice. The problem is with your comment on the limits of the envelope and that "no PC simulator does well at the limits", as I said I have the PMDG 744,748 and QW 787 and was able to land all in the same conditions without the strange aircraft behaviors I saw in the 777. I will provide a video shortly to show you how strange this is. I am trying to see if as you say it is an inherent limitation in the 777 PMDG product and if so why? thanks for your comments anyway, I am hoping to get that data.

Edited by pilotresponse

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1 hour ago, pilotresponse said:

I will provide a video shortly to show you how strange this is. I am trying to see if as you say it is an inherent limitation in the 777 PMDG product and if so why? thanks for your comments anyway, I am hoping to get that data.

This is a user-to-user forum.  I recommend you forward your observations, and I agree that they may be valid, to PMDG Product Support.  On first visit, you need to create a support account (support and sales are separate) then open a ticket and document your observation.  They will validate the issue and enter it into a bug tracking system for later use by developers when they touch this product again.  Proving the point in this forum will not result in any changes to the product.

The PMDG FCOM is a Boeing document, licensed to PMDG by Boeing for limited distribution with this product.

The issue could be related to their implementation of the fly by wire control laws, not sure how but maybe the AFDS vs autoland controlling behavior?  That's up to them to isolate.


Dan Downs KCRP

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Hasn‘t there been a bug that, after landing under certain circumstances, the 777 accelerated again and couldn‘t be slowed down? I remember that it had been fixed but I think I read somewhere that it seemed to have come back.. but I‘m definitely not sure, there‘s just something deep back in my head that there was something...


,

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Got an answer to the technical ticket I raised with PMDG

"It is a known issue with the simulator Ground Friction model and the aircraft that is currently under investigation.  We hope to have a solution in a future update."

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Hi, thanks for your information. I've detected this issue by landing the 777 but also with the 747. It is really strange and sometimes it can be really annoying if you're in the air for lots of hours and then couldn't do a clean touchdown. I'm also hoping for an update.

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