LoganCastle

Many good pointers, thanks a lot. I need this to work badly so I'm hell bent and exhausted on it. So I looked a little closer and I believe I isolated the cause but don't know what to do about it. If I approach the runway low (3 red on PAPI) just as I cross the threshold the runway jumps up about 30' or so and actually strikes the nose gear since it is the only part over the runway at that point (my angle-of-attack is good so why nose gear damage). That explains why I end up with a lot of collapsed nose gear instead of damage of other sorts. This also clears up why it only happens on sharp angle glide slope approaches. It probably happens at a normal angle also but it jumps too quickly for me to see and causes no damage. It would also explain why (as someone mentioned) it seems to happen on over-the-water approaches. There is no way for the scenery designer to taper the water . It seems to come down to this. The airport threshold elevation and the approach terrain elevation are misaligned. When I checked the field elevation for KSFO it seems to be specified as 13'. The altimeter in the airplane reads about 25'. If there were a way to lower the entire airport to align it with the terrain I think it would be solved. BUT I don't know how. Are airfields level so that all thresholds are at the same altitude? Are there airport add-ons that have runways that follow the terrain so all thresholds line up with the surrounding terrain.? Thanks for all the good pointers.

I'm not sure about how to reply to replies in this forum, so someone clue me in if you would. I initially had the problem with plain old vanilla FSX scenery and then thought maybe there had always been a problem with that so I tried an add on. Same thing. Then I went back to old FSX. Same thing. But if the elevation of the scenery at the threshold were too high wouldn't it show as too high in the sim visual? It looks fine. The aircraft looks fine. I don't know how the sim is written but there must be something that is there to detect when the aircraft is at the runway level to make them come together as a landing. The baro/alt and radio/alt reports the information correctly to the instruments and is displayed correctly and the bay/seawall/runway correspondences seem to be right but interference detection seems to fail. PMDG interference code may be sensing that the threshold and aircraft are trying to occupy the same space at the same time when they are not, in fact. So, are the altimeters reporting ok to the sim math but a decimal point is out of place? This may be unintelligible, if so I will try to clarify if asked. And some of you have noticed that this may be about AAR214, and it is. The irony is striking, ain't it!? Pun intended. Did 214 hit an invisible dirt pile? Hate those things! Yeah, KPMG, senior moment.

In the PMDG 777 when crossing the threshold on runway 28L at KSFO the aircraft crashes into something that is invisible when the approach is slightly low or shallow. After hearing the "thump" of hitting something I immediately pause the sim and go outside and see the aircraft is about 30 to 50 feet above the runway. I unpause and watch from the outside to see the nose drop to the runway and the nose gear collapse. It's broken. Baro/alt is about fifty feet. Radio/alt is at -2 feet after touchdown. Can the radio/alt ever legitimately be negative? Sometimes a cloud of dust is kicked up from the invisible obstruction. I see nothing wrong with the terrain image and nothing wrong with the runway image. Can the radio/alt be set to a higher value? Or are the values given by the radio/alt being misread by the KPMG model? Or what? Thanks in advance.

In the PMDG 777 when crossing the threshold on runway 28L at KSFO the aircraft crashes into something that is invisible when the approach is slightly low or shallow. After hearing the "thump" of hitting something I immediately pause the sim and go outside and see the aircraft is about 30 to 50 feet above the runway. I unpause and watch from the outside to see the nose drop to the runway and the nose gear collapse. It's broken. Baro/alt is about fifty feet. Radio/alt is at -2 feet after touchdown. Can the radio/alt ever legitimately be negative? Sometimes a cloud of dust is kicked up from the invisible obstruction. I see nothing wrong with the terrain image and nothing wrong with the runway image. Can the radio/alt be set to a higher value? Or are the values given by the radio/alt being misread by the KPMG model? Or what? Thanks in advance.