ASI erratic.

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DiamondFlyer88
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ASI erratic.

Post by DiamondFlyer88 »

Hi guys!

One of my girls is having an issue with the ASI reading zero most of the time during flight, at times it pegs to the top and dances around 40 kts for a bit and goes back to ZERO. I have had the air blown through the pitot line and the ASI bench tested and found to be working fine.. The static system is working fine as well. It is only the airspeed indicator with the issue.

Any thoughts on what could be the problem? Has anyone experienced anything similar?
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1911Tex
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Re: ASI erratic.

Post by 1911Tex »

Was the air blown through the pitot line in reverse (from the tube behind the ASI out)? May be debris (bug?). Need to be extremely careful not to produce more than very light breath pressure from pitot to ASI.
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DiamondFlyer88
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Re: ASI erratic.

Post by DiamondFlyer88 »

Yeah it was blown from the ASI out. I will have the shop check if the pitot tube itself is not the one with the problem..
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Derek
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Re: ASI erratic.

Post by Derek »

Is the pitot tube covered when not in use? If not it could have debris from bugs in it, perhaps mud wasps. Try taking the Pitot off and cleaning it out.
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1911Tex
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Re: ASI erratic.

Post by 1911Tex »

Also and no less important...I had a 182 with the same problem; turned out that the plastic tube at the inlet of the ASI had a hard to see crack or split where it connected. Might check that out as well?
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DiamondFlyer88
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Re: ASI erratic.

Post by DiamondFlyer88 »

The problem was the tubes were zip-tied too tightly together under the seats. Cut the zip-tie off and put a new one. ASI working just fine now. Thanks guys!
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