Airpeed appears to be way off

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Airpeed appears to be way off

Post by 8466 » Thu Mar 26, 2020 11:14 am

I've been watching several videos and asking several 140 pilots and they say approach speed for is 60-70 mph. I have tried that but it appears to be too fast so I have tried 50-50 mph and it seems to land (settle) better. Also the airspeed and altimeter are both bouncy.The airspeed indicator shows about 90 MPH at cruise but at calm wind the GPS shows consistently 90 knots. Has these aircraft had a history of pitot static problems or airpeed indicator/altimeter failures?

Thayne Inman

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Re: Airpeed appears to be way off

Post by 2356 » Thu Mar 26, 2020 3:36 pm

Read Neal Wright’s article pertaining to this issue.

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Re: Airpeed appears to be way off

Post by 1125 » Thu Mar 26, 2020 9:16 pm

Where do I find Neal's article? I'm curious about my 120's airspeed indicator also. TO :?:

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Re: Airpeed appears to be way off

Post by 2356 » Thu Mar 26, 2020 10:22 pm

On the 1st page of the website at the bottom. Forum archives.

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Re: Airpeed appears to be way off

Post by 8187 » Thu Mar 26, 2020 11:50 pm

I trim for 70 full flaps 1500rpm either 3pt or wheel. I would guess it sets below 45 on 3pt. That being said my ASI is errratic and it’s be rebuilt. I figure it’s a ballpark deal.

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Re: Airpeed appears to be way off

Post by 6863 » Fri Mar 27, 2020 7:15 am

Thane, approach speed and "over the fence speed' are two different things, "over the fence speed" being slower than speeds throughout the previous approach segments. So yes, slowing down to flare and touch down is required and will be slower than 60-70.
John Kliewer

"Make things as simple as possible but no simpler." Albert Einstiein

"Wheels move the body. Wings move the soul."

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Re: Airpeed appears to be way off

Post by 6643 » Fri Mar 27, 2020 8:04 am

1125 wrote:
Thu Mar 26, 2020 9:16 pm
Where do I find Neal's article? I'm curious about my 120's airspeed indicator also. TO :?:
viewtopic.php?f=10&t=133

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Re: Airpeed appears to be way off

Post by 8466 » Fri Mar 27, 2020 12:26 pm

Thank you for the information

Thayne inman

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Re: Airpeed appears to be way off

Post by 4004 » Fri Mar 27, 2020 12:29 pm

Prof John:
Rather than "giving a man a fish, teach him how to fish"!

Tell him on the "Forums" page scroll on down to the "Forum Archives" and he will find all the "Neal Wright" articles ( which you resurrected and posted for us when the page got corrupted) and I don't doubt he will find a wealth of info that he may need in the future!

The "debil made me do it"! :)

Happy Weekend

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Re: Airpeed appears to be way off

Post by 6643 » Fri Mar 27, 2020 2:40 pm

Good point.

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