747X Slams to Ground Short Final

[RFiery 0]

I have seen other threads where this has been mentioned in the past with no resolution.When flying on an ILS approach into KSFO on 28R (and 28L), the plane slams into the ground at 50 feet AGL every time. it is not because the plane is stalling. It happens on Autoland, or if hand flying the plane, at the same spot.I have flown other planes down the ILS and they all handle it fine, including the 737 NGX. So it does not appear to be a scenery error.To be clear, the plane literally drops down the 50 feet and moves forward a bit as well. It is like a time warp. I have "Ignore Crashes" selected. I have tried it both ways, same result. My specs:FSX SP2REX 2.0Default SFO sceneryWin 7 64 bitI7-2600 OC 4.86GB RamGTX 560TiAny help appreciated.Thx,Rick

[Ioan92 63]

Are you landing on the runways that extend in the bay?Never mind, I can't read It's a bug in FSX, happens at JFK too. Try landing on the other end of these runways and tell me if it happens again.

[engwerda 0]

RIck,It happened to me once too - at Sydney's 34L on a clear day. 50 ft to go hand flying it in, reaching for the throttle and about to bring the nose up at 30. Just as it said "50" I thumped onto the runway. No weather was set so it could not have been windshear. Have not seen it again since.Gerry

[scandinavian13 5,192]

Happened to me in the MD-11 at BOS one night. I added an AFCAD and it didn't happen the next time. Whether or not that actually fixed it, I'm not sure.

[downscc 1,327]

Kyle is spot on, add an afcad file and the problem goes away. Not sure if this is default behavior but that's the fix.

[RFiery 0]

Hey guys,Thanks - thought I was losing my mind. What do you mean by adding an AFCAD file. And if so any suggestions?Weird thing is it happens sporadically on 28L; but less often. No other places. I'll try an AFCAD once I hear back exactly what that means.thxRick

[RFiery 0]

Never mind on explaining AFCAD. I figured it out. I added a new AFCAD file for KSFO and that solved the problem.Well I thought it solved the problem. It worked the first time. Now it is doing it again....Any other ideas?Rick

[RFiery 0]

Are you landing on the runways that extend in the bay?Never mind, I can't read It's a bug in FSX, happens at JFK too. Try landing on the other end of these runways and tell me if it happens again.

If it is an FSX bug, why does it only happen with some PMDG planes?

[RFiery 0]

Hmmm. Seems like if I fly slightly above glideslope, the GS needle gets very unstable, but I don't crash. If I fly slightly below the GS, I get slammed down....Rick

[Ioan92 63]

If it is an FSX bug, why does it only happen with some PMDG planes?

It happens with every plane on my side. :/

[Guest venustus01]

This also occurs for me in FS9 with the pmdg 747.I found the problem only occured when autolanding.When "hand flying" the approach,all is well.

[RFiery 0]

This also occurs for me in FS9 with the pmdg 747.I found the problem only occured when autolanding.When "hand flying" the approach,all is well.

Was it at KSFO for you or everywhere?

[RFiery 0]

Never Mind - I figured it out I think!!!!I went to the settings page and set each slider to the left and unticked all the boxes and it landed fine.I then added back each item until I got the slam to the ground again.Long story short - I think it is the inter-relationship between the terrain mesh resolution and airports that are only a few feet above sea level. If I used any terrain mesh size less than 10m, it crashes the plane. If I use 10m (or greater), it works fine and the plane can be landed normally. I don't know how the mesh model works in FSX, but I have a feeling the wrong mesh size, coupled with the mesh complexity and the interaction with a perfectly flat mesh at the ocean is creating an invisible "mesh wall" right where the sea meets the land at the end of the runway.This issue has been reported to happen at KJFK as well, which is a similar airport. Sydney is the same. It worked for me at KBOS ONLY because I use FlyTampa scenery which is actually at sea level, so the terrain mesh wall was not created.Rick