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Jeff J
 Post subject: Retrofit Pitot Tube
PostPosted: Wed Feb 01, 2017 8:26 pm 
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Location: eastern OK
I would like to be able to park my T-18 under my Cessna to free up some space but the tail mounted pitot tube sticks up too far to get it under the wing. Has anyone changed the pitot tube location on an existing aircraft? Is it a feasible mod to a completed aircraft?
thanks


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Ryan Allen
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Wed Feb 01, 2017 9:14 pm 
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I would think its feasible. My pitot is in the wings gap between the outer wing and inner wing. I wouldn't think it would be that much harder to route tubing through the outer wing if you wanted the pitot out on the wing tip.


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fytrplt
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Wed Feb 01, 2017 9:17 pm 
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Seems to me that someone in the old days made a removable tail mounted pitot static tube. They removed it for hangar storage as you note.

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Bob Highley
N711SH
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bfinney
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Wed Feb 01, 2017 9:42 pm 
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My aircraft had the pitot/static on the vertical stab, the static is now on the sides of the fuselage and the pitot is mounted at the left wing tip. The old pitot/static tubes were cut flush with the top of the stab, the old tubing was left in place in the aft fuselage.

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Bruce Finney
N18JF T-18C #262
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Rich Brazell
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Wed Feb 01, 2017 11:34 pm 
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John Kerr just shortened his . :o

RB O0
El Chapo


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Jeff J
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Thu Feb 02, 2017 10:58 am 
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Location: eastern OK
Thanks for the replies. I will add it to the list of mods to be completed after I finish the upgrade I started in Nov that was only going to take a day.


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ljkrume
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Thu Feb 02, 2017 1:59 pm 
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Joined: Mon Oct 26, 2009 1:33 pm
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Location: USA
Since you raised the subject, my static ports are on the side, per old newsletter. Pitot is 1/4" OD on the left wingtip about 6" down and 3" ahead of the spar. I've always wondered if the diameter makes a difference. Anybody know? If I remember P=1/2 density*V^2, no mention of diameter.

Les


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fytrplt
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Thu Feb 02, 2017 10:20 pm 
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Diameter seems to be determined by what size bug you want to crawl up in there.

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Bob Highley
N711SH
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Binder
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Sun Feb 05, 2017 11:03 pm 
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Joined: Thu Sep 01, 2016 10:50 pm
Posts: 59
I'm changing mine as well. It's on the vertical stab and poorly accurate unless I'm in level cruise. On take off the slip stream causes it to bounce all around. When practicing stalls the indicator slows down to about 60mph then jumps back up to 90mph (while my ground speed continues to drop on the stratus) then it stays around 75ish as the wing buffets. I didn't really pay attention to the indicator until today when I was actually testing it at high altitude. Mine has quite a bit of warning before hand so I just use that when in the flare.

I'll be doing wing tip so I can also use AOA with a dynon 10a (or something similar which I haven't decided on yet).


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TonyNZ
 Post subject: Re: Retrofit Pitot Tube
PostPosted: Mon Feb 06, 2017 3:04 pm 
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Joined: Thu Oct 22, 2009 10:25 pm
Posts: 43
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Location: New Zealand
I have a PA 28 knife pitot/static mounted on LH wing. Positioned proportionally in the same place as on PA 28 Hershey bar wing. Has worked great for 27 years!
:)
Tony
ZK - VMS
T18c


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