Simviation Forums

I was just wondering, a question to perhaps some real world pilots out there, particularly higherspeed aircraft types....

Airspeed indicator, not altimiter (you probably knew that)  ;D.  My expertise stops there.

woops, my bad

Not intentionally. Red line is known as Vne, Velocity Never Exceed. The reason you see this happening in FS is either because FS doesn't model smooth changes in wind direction (it is never as sharp and abrupt of a change as the sim shows), or you're flying too close to red line.

Im sure that the never excede is a little under-rated for safety reasons. for example, let say that exceding 150 Kts. will cause structural damage, so the Mfg. puts the Vne at 140. I could be wrong, but almost everything is under rated like that. i.e. pipes and valves.

Of course, but it's still a Never Exceed point, to avoid undue damage that would result if the plane was pushed right to the limit on every flight.

Ya, I found out in another forum that this was the case of poorly modeling, different weather in various regions in real weather is what they said.  They also said the only way to solve this problem is to use programs like FSUIPC and Active sky, which are both expensive paywares...

I also notice something interesting last night though.  It seems that whenever my airspeed indicator showed a sharp rise, my lift increases as well (my altitude goes up), and likewise whenever it shows a sharp drop, my lift also immediately drops.  Now I was wondering if this can be related to a strong headwind or pressure zone when such things as abnormal airspeed rise occurs?  As the pitot tube is pointed forward and is a measure of Indicated Air Speed, I was wondering if this could be the case?  Could it just be the pitot system not measuring the correct airspeed because of this?  I know an increase in lift also means increase in air on the airfoils.  Just a thought...

Of course, but it's still a Never Exceed point, to avoid undue damage that would result if the plane was pushed right to the limit on every flight.

 Actually, the danger is not from catasrophic airframe failure but "mach tuck".  Most subsonic wings have a critical mach number. Even though the airplane may be travelling below the speed of sound, air that is being accelerated over the top of the wing can  exceed the speed of sound. Now, if you are in "coffin corner" and you experience a mach tuck......what will now happen when the aircraft is already past redline and now descending as result of the tuck?!  As an example, Mmo on the Lear 25 is .83. I have flown with a Lear test pilot to .86  before we started to feel aileron buzz and wing buffet. This is approaching the point of what's known as limiting mach. Yes, there is most certainly a margin for error factored into the barbers pole.

Do the planes every once in a while just jump past the overspeed marker on the airspeed indicator when encountering some heavier turbulence and wind?  

One aspect of high altitude pilot training for a jet is planning for turbulence and the jump that does indeed occur with turbulence. This is modeled correctly. Usually though, it only amounts to about a .2-.3(10-20kias) mach variation. On my airplane Mmo is .82. In heavy turbulence, I'll pull it back to .76 or less. I used to fly air ambulance in a Lear 25 and we would exceed Mmo regularly on the descent during critical patient conditions. Even though pilots are trained to plan for this condition, not all turbulence can be forecast or foreseen. "Bumping the Barber's Pole" is a regular ocurrence.

And if so, even so intermittently for a short corrected period of time, does that usually mean the aircraft would have to go straight to the shop?

No, BUT.........modern jets that have ACARS  can immediately notify the company if Mmo has been exceeded or for any number of other infractions. Big Brother is now a pilot as well?!  8)