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1 hour ago, Roger Lee said:

I've seen well past 2000 ft. loss at a straight dive at idle and 140 knots.

Mine is about like that.

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20 hours ago, Doug G. said:

I was taught during my last Flight Review to do an emergency desent by using a spiraling dive near vine. There were a couple of aviation deaths because of fires in flight last year in the general area. This was the method he had been taught flying for an airline to lose altitude as fast as possible while maintaining control.

I don't like the idea of turning near VNE.

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13 minutes ago, Tom Baker said:

I don't like the idea of turning near VNE.

I do this on my way home sometimes and its the descending unloaded turn we were talking about earlier.  I don't want to pull back on the stick near Vne but bank alone is quite comfortable.

In my CTSW if I was doing the emergency descent near Vne then I know my wings are unloaded otherwise I couldn't get that high speed.

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Structures typically are only tested for strength in one dimension at a time. Flying near VNE and turning could impose stresses that have not been fully tested. It is kind of like flying at Va. You can give full control deflection on any single axis whithout fear of structural damage. Combine motion in two or all three, and you could cause structural damage.

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If you stay within the g-limits of the airframe limits (+4/-2 for us), it should be okay since the aircraft is designed around those limits.  But because of increased airflow over the surfaces, it will take much less control deflection to hit those limits, and any unexpected condition like gusts could cause the airframe to exceed the limits.

If I need to go that fast for some reason like testing or practicing an emergency descent, I do it only in smooth air and I usually stop 5kt shy of Vne (140kt) and try to avoid maneuvering as much as possible.  I do agree with Ed that just banking with no stick back pressure should be safe, and the resulting turn should be extremely mild.

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Temps in the 30s this morning so I climbed to 14,000' in 10 minutes and tested out steeply bank descents to get into position for photos in these canyons: 

Its easy to see why you would do this for a fire / emergency descent.  The rotation is relaxed and the view gives situational awareness in spades, good thing to have when screaming down thru the layers.

 

Convict Canyon-11.jpg

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I would suggest that the following affects flutter when approaching Vne (not official, just personal observations):

-Vibration inputs from engine and/or propellor wash across the tail

-Tightness (i.e., absence of play) of control rods and linkages and hinges of the elavator and elevator trim.

-Stiffness of structure which the trim hinges are fastened to.

-Whether the elevator trim is "full span" or "partial span".

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I kept it out of the yellow so it was not that close to Vne. Still dropped fast in a controlled turn. A turn also helps blow the fire away from the fuse - if that is an issue. (That bit is out of the Skycatcher POH.)

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Friday I closed the throttle and began decent pushing over to just less than 120K. Rate of decent was  2000 feet per minute or more throughout a 2300 foot decent. The aircraft attitude was similar to using flaps 30 and holding 60K like I do in the pattern abeam the touchdown point. I certainly had no need to go to 140K for a faster decent. If I was on fire I might think differently.

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14 minutes ago, sandpiper said:

I certainly had no need to go to 140K for a faster decent.

Agreed,  I generally have to use TAS numbers but my high speed descents are usually 135kts.

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