Thanks for your extremely interesting real flight information.It is excellent for those of us who have never flown realaircraft.Peter Sydney Australia

for those with a technical interest check this out: http://www.avweb.com/news/airman/184284-1.html we're only simming, but this pretty much explains the source of overstress causing in-flight breakup. tt

Not only does this article trash the MSFS Vne failures it also trashes gear extension failures.The author advises dropping the gear if in a situation of a high speed dive way beyond VNE so ie way way above the gear extension speed.It could save your life.Peter

Could you be more specific when you say this "trashes" Vne failures?I just tried out a few scenarios based on the article in the FS9 Mooney. With full realism and all failures enabled I was able to exceed 300 knots in a level dive at idle power and then recover without failing the airframe. Alternatively I *was* able to fail the airframe at well *below* Vne (roughly 180kts) by using full control deflections. The airframe failed at 7 G's. Finally, below Va I was not able to fail the airframe at all. This is all as you would expect so I don't see any problems here.In this regard I think FS9's failures are pretty spot on and are related to G-loading. Given the pitch sensitivity of the Mooney at high airspeeds it's *very* easy to exceed the max G-loading. In fact, just as the article states, with the Mooney trimmed for level cruise flight I had to apply slight forward pressure on the yolk during recover to keep G-loading within reasonable (~3.5) limits. I think what the original poster was witnessing was a momentary G-load overstress that caused the crash. FS9 only needs you to exceed G-load for a few moments.You can argue that this isn't realistic but to make it so would require more advanced structural modeling that is not, IMO, what the sim is all about.Regarding gear failures FS9 doesn't actually support extending the gear above Vle. If you attempt to lower the gear you'll notice that nothing happens right away. Only after you slow to below Vle does it extend. The reason for this is probably buried in the deep-dark history of FS. I was able to trigger the "Gear Unsafe" warning in the Mooney (and get a Flying Tip to display in the Baron) after extending the gear and then accelerating above Vne. In effect this damaged the gear mechanism but I was still able to land. In this respect FS could be improved to allow extension above Vne (with the same damage).In summary I think the failure systems discussed in the thread are quite adequate for the average user and pilot using FS to train. After all it isn't called "Engineering Failure Sim".

To come back to your initial question. The wings are designed to produce lift. That is ensured through the shape the wing has. Every wing is designed for a certain purpose and speed range. Slow flying aircraft mostly have no or only little swept wings and a "thick" profil on contrary fast flying A/C's have swept wings and a "thin" wingsprofil. That means an A/C that is build for slow flying like the C152 has a much faster lift-force build up than a businessjet for example. Now the lift-force produced by the wings depends on different factors. Mainly they are the speed of the airflow, angle of attack and the shape of the wing. As a pilot you cannot influence the shape of the wing except of flaps and slats (we don't want to take those into consideration, because in highspeed flight you most likely have them retracted;)).What stays are the speed and the AOA. For example if you make a turn with a angle of 70 degrees you'll build up about 3G's. That means the airplane weights 3 times the weight than in level flight so the wing has to produce 3 times more lift if you don't want to loose altitude. If you hold the speed the AOA has to be increased to provide the lift needed. So a multitude of forces push and drag the wings upwards and to the rear. Those forces can be so big that the wing will collapse. As already has been stated earlier in this thread, there is a huge safety margin build in by the manufactures. One of the reasons is that turbulent air, wind gusts etc. can increase the Airflow over the wing temporarly to a very high speed. Such peaks are very dangerous and cause huge forces on the wings. The same with abrupt steering (increased AOA temporarly). Now thats for subsonic flight. For airliners, who fly at high subsonic cruising speeds excessive overspeeding can get them in trouble with the sound barrier and its effects.Now as a real world pilot its quiet easy to feel the forces, but as simmer you'll only get visual and audial input. The very important Gloads can't be simulated, so you'll never get the chance to fly the aircraft with "the ####":-cool.regards,Claudio.