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Turbulent Air Penetration Speed

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Turbulent Air Penetration Speed

Old 8th May 2007, 01:53
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Turbulent Air Penetration Speed

I was wondering when others use this speed. The definition says this is the maximum design gust value but does not really specify when to use this. Just would like some thoughts.
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Old 8th May 2007, 08:49
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When speed tape flutter is above 10 KIAS.
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Old 8th May 2007, 18:44
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Use the seat of your pants!

It's there for your judgment.
If the turbulence is bad enough that you tighten your seat belt you should probably slow to the TAP speed.
Or, maybe you inadvertently penetrated a thunderstorm. Good idea to slow down--or speed up, as the case may be!
Assuming you're American, I'd suggest reviewing the AIM for the classifications of turbulence. Anytime you experience moderate or greater is a good time to fly at TAP speed.
Good luck.
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Old 8th May 2007, 19:47
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zero zero summed it up, its up to your judgment.
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Old 8th May 2007, 21:13
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What amazes me, is the number of pilots who think this is a maximum speed, rather than a target. I see guys who enter turbulence at or around TAP speed and slow down!
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Old 8th May 2007, 21:28
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i penetrate the air at about 65kts when flying the druine turbulent.
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Old 9th May 2007, 00:55
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Hmm

<<i penetrate the air at about 65kts when flying the druine turbulent.>>

What's that? Some of that Olde English?

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Old 9th May 2007, 03:20
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Thanks

I appreciate the responses as there seems to be no guidance. I have always used moderate or greater as my rule of thumb but I see people get into it and slow way down in light turbulence.
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Old 9th May 2007, 03:28
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In the early days of jet transport flying, pilots who had come from piston transports tended to slow w a y down when turbulence was encountered, and if this was at or near the aerodynamic ceiling for the weight, often found the classic jet upset was in the cards.
This was....very bad news.
Unfortunately, the older jets had rather poor data on the proper speeds to be flown in turbulence, so this certainly didn't help.
The L1011 for example has very good data on the subject, provided of course that the pilots actually READ it in the AFM...some of course apparently know better
I even had one pilot long ago mention that the L1011 wing was unsuitable for any flight above FL350 saying....'it's just like the Constellation, a bad performer up high.'
I asked him if he had actually referred to the performance data and the answer was....'why bother, it's all a bunch of nonsense anyway.'
Some never learn
L1011 Turbulence speeds... M.82-.84 or if above 290KIAS, slow to that speed regardless of mach number.
This is for the standard body aeroplane, short body similar.
Get the TriStar too slow, expect big problems as the aeroplane is designed as a high speed cruiser.
Cruise all day long at M.86 (standard body aeroplane), passing most anything else like they were dragging a boat anchor.
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