ASI Questions...
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- Posts: 229
- Joined: Tue Nov 27, 2018 10:53 pm
- Name: Tamer A
- Location: KSNA
- Aircraft Type: 1946 C120 O-290-D
- Occupation-Interests: Engineer
- Contact:
Re: ASI Questions...
Just out of curiosity, whats the standard practice with multiple pitot instruments? Can you daisy-chain them like the static system?
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- Posts: 2477
- Joined: Tue May 01, 2018 7:00 am
- Name: John C
- Location: KLCI, NH
- Aircraft Type: 1946 C140/C90
- Occupation-Interests: A&P, semi-retired
- Contact:
Re: ASI Questions...
I wouldn't call either one a "daisy chain," which brings to mind output of one connected to input of the next. What you need to do is split the static line so each instrument has a direct path to the static source. Likewise for the pitot line. (Probably what you meant anyhow). Neither line has (should have) any net flow, so there's no issue connecting several instruments to the same line using "T" fittings.
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- Posts: 58
- Joined: Sat Jan 05, 2019 11:21 pm
- Name: Franklin B
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Re: ASI Questions...
If you browse through FAA AC 43.13-1b there's a section that shows the pressure loss formulas when building/repairing pitot static systems.
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- Posts: 58
- Joined: Sat Jan 05, 2019 11:21 pm
- Name: Franklin B
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Re: ASI Questions...
UPDATE: I cleared the pitot and static lines a few days ago. I removed the line to the static port. Just took the plane out on a calm day. What a difference.... The ASI and the GPS speeds are nearly identical. ASI is working like it's supposed to now.
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- Posts: 97
- Joined: Tue May 01, 2018 7:00 am
- Name: Martin Tanguay
- Location: Montreal, Quebec, Canada
- Aircraft Type: C140
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Re: ASI Questions...
Great, but keep i mind that you flew on a calm day and could be the reason why they almost matched. Don't take for granted that ASI and GPS will always match. There is a methodology in the member section to check your ASI using your GPS flying four different headings and doing some calculations.
Martin Tanguay
Intl Cessna 120-140 Association - Canadian rep
C140, C-FJAR, 1946, sn:9168, O-200, ragwings
Intl Cessna 120-140 Association - Canadian rep
C140, C-FJAR, 1946, sn:9168, O-200, ragwings