Strange behavior just before touching down

[avrbifly 0]

I was reluctant to post anything, but this same issue has shown up on my new i7 build so I'm wondering what might be the underlying cause. I'm running the MD-11 with Ultimate Traffic 2. On my last system it was very repeatably that on approach to 33L in BOS at about 50-100 feet on short final the airplane would suddenly leap onto the runway. Kind of startles you because you'll suddenly hear the firm touchdown and the Spoilers deployed call. I thought it was just some bug with BOS 33L, but last night on my new system I got the same repeatably results landing at LGA RWY 13 and 22. Only common HW component between the two systems is the PNY 9800GTX+ card, but I wouldn't think that would have an effect? Anybody have any ideas. This is a definate head scratcher.Thanks,Richi7 920 6G DDR3CAS7 PNY 9800GTX+ 512MB video

[Turbine777 13]

Hi Rich, Interesting problem. I wonder if FSX is recaching at this point and your CPU is playing catch up. I fly out of or into Boston several times a day and 33L a lot lately since the winds have been gusting in that direction.Try this: This isn't my finished file, but a close final (cannot find my finished after an hour of looking :( ). It is a more realistic Logan (KBOS), with actual Taixways and new runway they did a few years ago. I will continue to look and hopefully find the finished file and update later.Unzip this file and place it in your FSX\Addon Scenery\scenery folder. It will overide your KBOS file and to uninstall it, simply remove the file from that folder. Do the same approach and see if you get the same results. I know this isn't an answer but might see if it's your afcad/bgl file.Download my file here.Also, try running in windowed mode and see if the same thing happens. The file load will be different enough to cause the hiccup a little later if it is a recach problem of some sort. In windowed mode you can also run Task manager and keep an eye on your other processes to see if any are spiking your CPU usage at the time, although I doubt it would be seen as anything other than fsx.exe.

[downscc 1,327]

Dan, so you are thinking it is a stutter? I was trying to visualize Rich's 'leap to the runway' but it eludes me. Rich, does this happen before you flare and you suddenly find yourself on the runway? What does a playback look like (ignore things like spoilers in MSFS playback)?

[avrbifly 0]

Dan, so you are thinking it is a stutter? I was trying to visualize Rich's 'leap to the runway' but it eludes me. Rich, does this happen before you flare and you suddenly find yourself on the runway? What does a playback look like (ignore things like spoilers in MSFS playback)?

yes before the flare and suddenly on the runway. I will look at the playback next time it happens.Rich

[Turbine777 13]

Dan, so you are thinking it is a stutter? I was trying to visualize Rich's 'leap to the runway' but it eludes me.

Not sure but it's possible. Our systems are very simalar in specs and as you get within certain ranges certain scenery pops into view. I experience this pop, but rarely where there is a stutter like this that would skip time. I have seen issues where the CPU seems to play catchup, when all of a sudden things speed up 10x for a second or two where you experience sluggishness then all of sudden get all your callouts at once, one after another. Anywho, not even sure he saw my comment at this point.

[avrbifly 0]

Not sure but it's possible. Our systems are very simalar in specs and as you get within certain ranges certain scenery pops into view. I experience this pop, but rarely where there is a stutter like this that would skip time. I have seen issues where the CPU seems to play catchup, when all of a sudden things speed up 10x for a second or two where you experience sluggishness then all of sudden get all your callouts at once, one after another. Anywho, not even sure he saw my comment at this point.

Funny thing is there is no pause with this. My sim is running pretty smooth nowadays. And all seems good as you approach. You are thinking about the upcoming flare and then suddenly you are firmly on the ground and ahead of the last position you were in. No pause or stutter involved. I'll investigate some more.Rich

[Turbine777 13]

Funny thing is there is no pause with this. My sim is running pretty smooth nowadays. And all seems good as you approach. You are thinking about the upcoming flare and then suddenly you are firmly on the ground and ahead of the last position you were in. No pause or stutter involved. I'll investigate some more.Rich

Well, yeah it is similar behavior but without the pause. There doesn't have to be a noticable pause at all to get the time skip. Something is causing a hiccup in your system I imagine, and if it's happening all the time like you said and at the same spot, then that's all I can think of. After all, it isn't like it's a movie that you're watching and someone just clipped a few seconds off, so it makes guessing what the issue is here fairly easy.Have you tried what I mentioned in my first responce?

[downscc 1,327]

Rich, I am afraid it sounds like you are touching down before you expect to due to a high pitch angle at touchdown and the wheels are way back there much lower than the cabin. Check your playback friend.

[avrbifly 0]

Rich, I am afraid it sounds like you are touching down before you expect to due to a high pitch angle at touchdown and the wheels are way back there much lower than the cabin. Check your playback friend.

No... It is definately not that. It leaps forward just past the 50 to 100 foot call and is down on the ground spoilers deployed. Wondering if some sort of pre rendering issue?Rich

[avrbifly 0]

No... It is definately not that. It leaps forward just past the 50 to 100 foot call and is down on the ground spoilers deployed. Wondering if some sort of pre rendering issue?Rich

So it gets even more interesting. Decided to watch an autoland to rwy 22 LGA. Everything looks good then at 70ft RA the plane leaps onto the runway then jumps suddenly 500 feet in the air. Don't know if it's a clue, but this was accompanied by don't sink don't sink. very odd! The instant replay from the tower shows the same thing. I will try turning Ultimate traffic off to see what happens.Rich

[downscc 1,327]

Wow, I can't wait to hear what is causing this one. You are so lucky to have such an odd problem. It acts like a crash, turn off crash detect if it is on. Turn off all add-on scenery by unchecking it (you don't have to uninstall or reinstall, just put the check marks back when this is ruled out). Run the MD11 installer and select repair, repair the airplane and C++ files. Try an approach at half speed... I am just brain storming.What ever you do, please do report the solution when found. You will find it, I'm sure.

[KCA9304 0]

Wow, I can't wait to hear what is causing this one. You are so lucky to have such an odd problem. It acts like a crash, turn off crash detect if it is on. Turn off all add-on scenery by unchecking it (you don't have to uninstall or reinstall, just put the check marks back when this is ruled out). Run the MD11 installer and select repair, repair the airplane and C++ files. Try an approach at half speed... I am just brain storming.What ever you do, please do report the solution when found. You will find it, I'm sure.

Dan, Rich,Seen this before.There's a common thing about these runways, approach over water and a threshold, right when making land.KJFK 04L qualifies for this scenario as well.IMHO, It's an elevated threshold too close to (underlaying) water that causes this problem.Have seen this in the Queen and MD11 as well.Adapting the default scenery with ADE helped solving this problem on my side for known airpot/rwy situations.Would be even better if the PMDG aircraft could cope with this.Regards,Harry@Dan: working on a signature.

[avrbifly 0]

Dan, Rich,Seen this before.There's a common thing about these runways, approach over water and a threshold, right when making land.KJFK 04L qualifies for this scenario as well.IMHO, It's an elevated threshold too close to (underlaying) water that causes this problem.Have seen this in the Queen and MD11 as well.Adapting the default scenery with ADE helped solving this problem on my side for known airpot/rwy situations.Would be even better if the PMDG aircraft could cope with this.Regards,Harry@Dan: working on a signature.

I think Harry is probably correct. I ran a bunch of tests UT2 off/windows mode/nhancer prerender settings/flap GPWS flap override et al. Didn't change a thing. Always the same leap to runway and jump up 500 feet ( Autoland ). I can only land normally on 04 at LGA. I tried Dan's BGL at BOS and same results for 33L. No problems landing 15R though. No problems at SFO?? Interesting that I can take off at LGA rwy 4 and hold the M D-11 on the ground towards the threshold of 22 and the plane leaps up in the air 500 ft. So must have something to do with the water/land boundery. Then the question is why do I see this and others don't? Is there some CFG setting that can be linked to this issue? video card? anything??Rich

[aentwis 61]

Do you have crash detection and so on enabled or not?I cannot remember the settings here, as I am not at home right now, but I remember that at least one of these settings, on crashing, throws the aircraft to around 500ft AGL...Andrew

[Turbine777 13]

Andrew beat me to it but yes, this does sound like your realism settings are set to not detect crashes. Of course this doesn't fix the problem, but being shot up 500' in the air is exactly what is done in that case when a crash is detected. I still cannot find my completed KBOS file which is sad, but trying my posted one above produced a crash (not lock up) on my first attempt flying 33L. Harry may be on to something here, but I can't see where the issue is in ADE. It seems like there's an invisible mdl right before the runway and my MD-11 just crashes 100' above the runway threshold.