The Touchdown bug of PMDG

[PavlinS 179]

For some time [ 4 years] I own the PMDG 747 / 777 all models and I am noticing an issue with the speed lately when I land. Not to mention the bounce landings on the 777 / 747. Of course, I submit ticket with the PMDG so I can discuss the issue and to be solved. 

For a week of responses I get that they blame all the stuff happening on other issues. I shared number of videos and even with autoland the 777 is very tricky on the speed. 

 

 

Check at 3:38 - this is the moment of touchdown, then you will see that the speed goes down, then up, than again down, then up. 

Even on autoland this is happening, in smaller scale, but happening. 

 

 

 

I am at final at 2:33. 

 

First time they blamed me for touching down too hard, which I think was a little discriminatory. 

Second time they said there is no problem. 

I researched the topic and I ended up on two forum topics about it. 

 

https://forum.pmdg.com/forum/main-forum/pmdg-777-forum/112961-touchdown-bug-still-exists

 

 

In the first topic there is examples with 777 and 747 with this problem. 

Still, PMDG says that nothing is wrong, nvm all the videos and the resources I shared with them. This is not an isolated issue. 

So, my question is - is there a way to fix this? I attempted the way of fixing it via the topic from here for bouncing, but that did not give me any solution, even worse, every landing became bouncy even if I touchdown correctly. 

I submitted ticket towards PMDG. For now the agent is just neglecting my request to check what is wrong and to help me fix it. 

Obviously those two planes are in not good shape, obviously this is a bug to me. I don't understand - why they do not wanna fix it? I never had such issue nether with Quality Wings 787, which I also fly on regular basis, or the Vertx Diamond DA-62 and the Carenado Bonanza A-36 that I own. Only on PMDG 747 / 777 this happens. 

 

[VHOJT 185]

There is something weird, at least with the 747 (haven't tried the 777), that if the nose is held up, it will not decelerate and will pick up/lose/pick up/lose speed unless you point the nose down.

They said at one stage it was a P3D limitation.  Take that with as much salt as you like.

https://forum.pmdg.com/forum/main-forum/general-discussion-news-and-announcements/pmdg-747-queen-of-the-skies-ii-forum/24207-autobrakes-not-working-sometimes

Edited April 2, 2023 by VHOJT

[LRBS 961]

@PavlinS,

 

This is a known problem with PMDG for the 747 and 777. I'm quite surprised that they didn't delete your message. They can't accept any criticism. There is no surprise for not answering the obvious or you might get this kind of response.

//////////////////////

This is known to happen from time to time, a few users has reported this but until now it is not reproduced in our systems.

/////////////////////

On the first manual landing, you were way above MLW, you touched down below Vref at about -13 KTS at a ROD of about 300 FT/MIN.

For the 777 MLW is roughly at 554,000 LBS and you had 696,000 LBS. Not ideal at all unless there is an emergency.

 

On the second one, right on speed, touched down at about 250 FT/MIN. The issue with the A/L on PMDG is that almost all the landings are harsh. The 747 and 777 in A/L mode does greasers all the time unless there is a malfunction. 

And this nonsense with gaining speed like that after landing is going on for years, like many other issues.

If you gonna push it, most likely they gonna find a way to ban you from the "user to user" forum.

Edited April 2, 2023 by Ray Proudfoot
Large quoted post removed

[Beardyman 612]

I think they gave up P3D development even not officially said, so there is a little chance any remained issues to be fixed - wish to be wrong here

[Christopher Low 5,414]

Why does the plane look like it is flying incredibly slowly in the first video? That does not look right at all. As for the second video, I am struggling to find anything wrong with it.

[Ray Proudfoot 9,053]

1 hour ago, Christopher Low said:

Why does the plane look like it is flying incredibly slowly in the first video? That does not look right at all. As for the second video, I am struggling to find anything wrong with it.

Ditto. On the first video the landing speed of 170kts is far too high. It’s faster than Concorde!

Also, the landing/ flaps configuration hasn’t been set in the CDU. Look at the red bars on the speed tape.

It’s taking so long to slow down it makes me think there’s too much fuel still onboard.

@PavlinS, how do you plan your flights especially regarding fuel. I don’t have the 747/777 but it has to slow down quicker than that.

[willy647 194]

Speed 170 and it looks like slow motion  ?????

[PavlinS 179]

The first landing was that high because I did not managed the fuel at all. I just wanted to produce a landing for a video and that's it. I usually manage the fuel when I do a flight, because I do only long hauls with that plane. When it comes to the slow motion - I always land in slow motion. Departure and arrival I always slow down sim to the lowest speed possible, so I can have time to make corrections on my course.  That makes for more practice of me to land properly. Unfortunate is, this time I did not. Thank for the comments. I did not wrote in the user to user forum, I submitted a ticket. So, you are telling me, that PMDG won't take this issue seriously? Thank you for telling me. I am really, really surprised. 

 

Edited April 2, 2023 by PavlinS

[PavlinS 179]

And btw, I have good landings with that plane, occasionally - for example this one:

 

 

This is a flight vlog video of me doing long haul from Amsterdam, Netherlands to Kuala Lumpur in Malaysia. Landing footage is on 15:56

[Ray Proudfoot 9,053]

34 minutes ago, PavlinS said:

The first landing was that high because I did not managed the fuel at all. When it comes to the low speed - I always land in slow motion. That makes for more practice of me to land properly. Unfortunate is, this time I did not. Thank for the comments. I did not wrote in the user to user forum, I submitted a ticket. So, you are telling me, that PMDG won't take this issue seriously? Thank you for telling me. I am really, really surprised.

They won't take you seriously unless you fly the aircraft seriously. Not planning fuel means you were probably overweight for landing on that first video. You've shown in a later video there aren't any problems once the aircraft is correctly configured.

As for landing in slow motion that's up to you. Personally I'd be inclined to stay in normal mode and learn how to land it. Disengage AP and Yaw Damper once flaps are fully down around 4 miles out. You can leave Autothrottle on until later but try disconnecting around 2nm out and then you have full control for the landing. It's very satisfying to do a nice landing.

[PavlinS 179]

My pc is slow. I gain more fps that way. Also, I always disengage the A/t when I land it. You prob. noticed in the new vid I put. And please, can we focus on the subject? How I land is not the matter of discussion o doe I am appreciating the positive criticism. 

Edited April 2, 2023 by PavlinS

[Ray Proudfoot 9,053]

1 hour ago, PavlinS said:

can we focus on the subject?

Plan your fuel correctly and you won't get the problem. Also, use INIT REF to configure the aircraft for landing.

[PavlinS 179]

2 minutes ago, Ray Proudfoot said:

Plan your fuel correctly and you won't get the problem. Also, use INIT REF to configure the aircraft for landing.

That landing you saw after was made after 2 days in which for 20 hours I practiced that landing. Also it is video from 2021. When that problem was not regular occurrence. Thank you for the tip, but I sincerely doubt that even if my landing is perfect this problem will disappear. 

[Biggles2010 345]

14 hours ago, PavlinS said:

For some time [ 4 years] I own the PMDG 747 / 777 all models and I am noticing an issue with the speed lately when I land. Not to mention the bounce landings on the 777 / 747. Of course, I submit ticket with the PMDG so I can discuss the issue and to be solved. 

 

As well as what others have said about the first video and the incredibly high Vref due to excess weight, there were 2 other things that stood out to me.

First was the that the visual perspective was not quite correct. The zoom level in use gave a view which made the whole approach look very low and flat, which did not correspond to the correct situation displayed on the instruments. This affects your judgement in the latter stages of approach, especially when preparing to flare. Throughout the approach it looked like you were aiming for the beach.

Secondly, after crossing the threshold, at 2-55 in the video,the backward movement on the controls was excessive. More like rotating than flaring. The aircraft inertia at high weight meant this took effect as you touched down, so it was inevitably followed by a bounce and a second landing. At very high weights it is more critical than ever to control the vertical flight path carefully.

[PavlinS 179]

7 minutes ago, Biggles2010 said:

First was the that the visual perspective was not quite correct. The zoom level in use gave a view which made the whole approach look very low and flat, which did not correspond to the correct situation displayed on the instruments. This affects your judgement in the latter stages of approach, especially when preparing to flare. Throughout the approach it looked like you were aiming for the beach.

Which attempt you are talking about, the first post second video? If yes, then this is not VFR approach, this is complete autoland. PMDG agent asked me to do that. Also that approach was without add-on's, due to the fact that the agent asked me to remove all my add-on's for this approach. 

Edited April 2, 2023 by PavlinS