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  #51  
Old 12-22-2010, 04:01 PM
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Kevin Horton Kevin Horton is offline
 
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Quote:
Originally Posted by Sig600 View Post
I can't believe I'm asking this question, but I can't think of a good answer...

In an unpressurized vessel (i.e. an RV) why can't you get a source of static air from within the plane itself? Something like an open port within the empennage?
The air that goes around the aircraft is accelerated as it goes around the fuselage, just as air is accelerated as it goes around the thicker parts of the wing airfoil. Bernoulli's Law tells us that the static pressure of this accelerated air is lower than the ambient pressure. The cockpit is exposed to the lower pressure air around the fuselage by the small leaks around the canopy. Thus the air inside the fuselage is usually a bit lower pressure than the ambient pressure. The air pressure in the fuselage also varies depending on whether the fresh air vents are open or closed.

RVs with leaks in the static system typically have IAS that read roughly 10 kt too high in cruise. The altimeter would also read 100 to 200 ft too high.
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  #52  
Old 12-23-2010, 12:39 AM
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Ahhhhhhhh the GURU has arrived!

Listen to him.....he knows stuff!
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  #53  
Old 12-23-2010, 08:06 AM
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Quote:
Originally Posted by Mike S View Post
O.K., are you cutting them in half first? so they look like the setup in this photo I borrowed from David?

Hey Mike:

I am referring to the wing mounted mast type pitot-static devices. The O ring is sized to slide over the tube and adjust the static pressure in flight. The picture you posted shows one method of tuning the fuselage mounted static ports...

Sorry for any confusion!

Carry on!
Mark
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  #54  
Old 12-23-2010, 09:36 AM
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Mark, thanks for the clarification------
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Flying as of 12/4/2010

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  #55  
Old 12-23-2010, 10:08 AM
Bavafa Bavafa is offline
 
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I have a flush mounted static, drilled a hole in the middle of a #10 screw and I believe my IAS is on the slow side. Time to test this again and see if I can get it more correct. I like the low pass test and see what the altimeter says.
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  #56  
Old 12-23-2010, 10:15 PM
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Fly a GPS box and compare it to the TAS on your EFIS if you have one. Thats the easiest method.

try to do your runs under the same conditions (i.e. Temp/QNH/Throttle/rpm/mixture) that way its easy to compare.

Low level with all the levers forward is the most fun too!
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  #57  
Old 12-24-2010, 10:18 AM
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Quote:
Originally Posted by Phil View Post
Does anyone have any experience with the Cleveland ports installed in the RV-10 standard location?

http://www.cleavelandtoolstore.com/p...p?number=SPF50

These are what I installed early in the project without having talked to others about their static port choices on the -10. I wish I had gone the SafeAir route, but I'm curious to know if anyone has experience with these.

Thanks,
Phil



I have these static ports as well and can not quite figure out If there is a quick connect coupling available for the barb end. I look up the safeair1 kit and stein air's kit but could not decide which one is better. Did anybody use either kit. What is your recommendation?
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  #58  
Old 12-24-2010, 03:21 PM
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Quote:
Originally Posted by G34U View Post
I have these static ports as well and can not quite figure out If there is a quick connect coupling available for the barb end. I look up the safeair1 kit and stein air's kit but could not decide which one is better. Did anybody use either kit. What is your recommendation?
Give Stein or Jed a call at SteinAir.

I can't quickly put my hands on the details, but they do carry additional parts not on their web site and can set you up will everything you'll need.

All my parts that I got from them are setting in a box at the airport.

bob
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  #59  
Old 12-24-2010, 03:30 PM
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I used Tygon tubing from Cleveland. The 1/4" hard static lines slide nest into the larger 3/8" tygon tubing.

They probably air-tight on their own, but I went ahead and mixed up a batch of pro-seal and put it on the 1/4" tubing before inserting it into the tygon. I believe it's completely air tight now.

Phil
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  #60  
Old 12-24-2010, 10:02 PM
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Bill.Peyton Bill.Peyton is offline
 
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Well I just ordered the Safeair1 static ports and are going to give them a try. I spoke with them and they claim that they are machined to replicate the Pop rivet and to sit at the same distance from the fuse as the Pop rivet style. They also came with the snap fittings, tubing etc for both the pitot and static system, and have a compression connection to the port. Time will tell how accurate they are.
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