Originally Posted by markjoy
Extreme; aircraft movement is violent and is out of control most of the time, structural damage occurs. (In practice, severe is rare and extreme almost unheard of.)
But not quite.
Originally Posted by markjoy
3) Personally, slow to turbulence speed or Va, try not to overcontrol, make a joke about counting the wings to reassure the passengers, and depending on the cause, a change of altitude or route can help. As an airline passenger, I keep the belt on whenever seated and marvel at the flexing of the wing.
4) Yes. But this would be rare. And I think for a large aircraft, very rare.
5) Sometimes a little. As a passenger in an airliner, very seldom. Don't think I've ever experienced severe turbulence in an airliner. Maybe moderate to severe.
6) In the word of E.K.Gann,( "Fate is the hunter"), "It's margins of strength are beyond my understanding."
If I remember rightly, lighties are certified to +3.8 and minus 1.7G. Air transport aircraft, such as a Boeing, probably similar or greater. There is a 50% margin required on top of that. You hardly ever hear of inflight breakup as a direct result of turbulence.
But sometimes you do.
There is that BOAC 707 that was ripped apart in Japan by turbulence.
As for Boeing G tolerances, there is that China Airlines 747SP that fell off the sky (It had rolled over). The black box was broken by the acceleration, so the g-s achieved were over 5g, but exact numbers are unknown. The wings were permanently bent - slightly, and they remained within tolerances. Parts of tailplane broke off.
Out of over 270 people aboard, one had a leg injury and another had back injury. Everyone else was unscathed.
With people, it may have helped that the g-s were steadily down - not throwing around. As for airframe, perhaps it helped that the plane was light approaching destination over Pacific, not fueled to MTOW any longer.
There have been people killed by turbulence in airframes that kept flying.
Originally Posted by markjoy
The more likely hazard is windshear related-a type of turbulence that results in a loss of airspeed with a change of altitude. This can be hazardous on final approach. At the airport where I work, it's a frequent occurrence. Seen some interesting approaches; never seen a crash.