---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Thu 01/27/05: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:16 AM - Varnished wings--Pietenpol Fly-In (rhartwig11@juno.com) 2. 06:04 AM - lift strut angle (Oscar Zuniga) 3. 07:28 AM - Re: Accurate Wood List (Les Schubert) 4. 07:39 AM - Re: Varnished wings--Pietenpol Fly-In (Galen Hutcheson) 5. 08:17 AM - Re: Lift strut angle (Bill Church) 6. 11:59 AM - Static port (Norman Stapelberg) 7. 12:42 PM - Re: Static port (Phillips, Jack) 8. 01:34 PM - Re: Static port (walt evans) ________________________________ Message 1 _____________________________________ Time: 05:16:36 AM PST US Subject: Pietenpol-List: Varnished wings--Pietenpol Fly-In From: rhartwig11@juno.com --> Pietenpol-List message posted by: rhartwig11@juno.com The plane with the varnished wings is owned by Tom Brown. To get his address, email the Brodhead Chapter webmaster by clicking on the link at the bottom of their website. Brodhead Chapter website is: http://www.eaa431.org The Piet Fly-in is July 22-23, 2005. Dick H. ________________________________ Message 2 _____________________________________ Time: 06:04:50 AM PST US From: "Oscar Zuniga" Subject: Pietenpol-List: lift strut angle --> Pietenpol-List message posted by: "Oscar Zuniga" Just to add one more data point to the growing pile, the wing lift struts on NX41CC are right at 30 degrees from horizontal, and I believe the wing cabanes are lengthened a bit to raise the wing. But I looked at the geometry in CAD and tried moving the wing back down to stock location and it only reduces the angle a degree or two. Twenty degrees wouldn't seem to be correct in any case that I looked at. Oscar Zuniga San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 3 _____________________________________ Time: 07:28:53 AM PST US From: Les Schubert Subject: Re: Pietenpol-List: Accurate Wood List Derek I bought a Piet wood kit from Aircraft Spruce. Just before it was ready to ship they called me to say that the rib cap strip was not included in that price and was extra. About this time I found a partly built Piet project so I have never opened the boxes to inventory it, figured it was safer in the crates as it came. I didn't buy the cap strip as I knew I wouldn't need it at that time. Hope this helps. Les At 04:35 PM 26/01/2005 +0000, you wrote: >I've just received my plans and need to order the wood for a long bodied >three piece wing aircamper. I'll be ordering from Aircraft Spruce and >shipping to Europe so I want to avoid any mistakes. I've seen a wood list >mentioned in the archives (Sep 04) and would appreciate it if someone >would e-mail me a copy. > >Regards > >Derek Doyle ________________________________ Message 4 _____________________________________ Time: 07:39:46 AM PST US s=s1024; d=yahoo.com; b=0rYSAKXtO7vJFweWpF9/ddwP70nf1IDIGYd+lkYHkc/QAN/6N9uVRS1wau5RXH3lZ97z4iBkzO9Neibq+TJor2AOnr+W4Ofc6K3VWFSB/rKFoM4vvCl+g0Aeo95t8wt7KQxZRvfkx2ytTFuSm0ebYR8hLESlNEMkwi2lmGQiGXA= ; From: Galen Hutcheson Subject: Re: Pietenpol-List: Varnished wings--Pietenpol Fly-In --> Pietenpol-List message posted by: Galen Hutcheson Dick, thanks for that info. I will contact them soon. I hope to make it to Broadhead this year, if all goes well, but I doubt my plane will be ready. Doc - > > > > > > Contributions > any other > Forums. > > http://www.matronics.com/subscription > http://www.matronics.com/FAQ/Pietenpol-List.htm > http://www.matronics.com/archives > http://www.matronics.com/photoshare > http://www.matronics.com/emaillists > > > > > > __________________________________ http://mobile.yahoo.com/maildemo ________________________________ Message 5 _____________________________________ Time: 08:17:40 AM PST US From: Bill Church Subject: RE: Pietenpol-List: Lift strut angle --> Pietenpol-List message posted by: Bill Church Subject: Re: Pietenpol-List: Lift strut angle Clif wrote: --> Pietenpol-List message posted by: Clif Dawson Jim Wills plans? Clif, I believe Rod was referring to the Pietenpol plans modified by Jim Wills, for PFA (UK) approval . I understand those plans have a few modifications including a quick-disconnect for aileron connections (since the majority of UK Piets will only be flown in summer and stored for the winter) and built-up spars (because spar stock is scarce in the UK). There are likely other modifications/corrections, and I believe that variation from any details on those plans must be granted a concession by the PFA (correct me if I'm wrong, anyone who knows better). Bill ________________________________ Message 6 _____________________________________ Time: 11:59:33 AM PST US From: "Norman Stapelberg" Subject: Pietenpol-List: Static port --> Pietenpol-List message posted by: "Norman Stapelberg" Hello Fellow Piet pilots Thought I'd pass this one out there, went flying in my plane with the instructor, only to find that the air speed and VSI react as the power setting is changed, it seems I have a problem with the static port. I am currently using a pitot/ static tube, the static tube sits about 4" below the wing with the pitot tube another 2"lower. The front cockpit also has a ASI and Altimeter, these however are not connected to the pilots static system, the front Altimeter reads 100' higher than the rear cockpit, the ASI reads 10mph higher than the rear instruments. My thoughts are to plumb all the instruments to the static system, and then to use an alternate static port, my question is this where would the best place to pick up a reliable static position. To date we have flown 2hrs since the rebuild and everything else seems in order. Thanks Norman Stapelberg South Africa ZS-VJA (121hrs) ________________________________ Message 7 _____________________________________ Time: 12:42:05 PM PST US Subject: RE: Pietenpol-List: Static port From: "Phillips, Jack" --> Pietenpol-List message posted by: "Phillips, Jack" Hi Norman, The first question that comes to mind is where are your pitot tube and static tube in relation to the leading edge of the wing? If they are behind the leading edge, 4" is probably not far enough away from the wing to truly read "Free-stream" air. If you look at other similar speed airplanes, such as a J-3 Cub, you will find that the pitot tube is located considerably lower than that - about 12" as I recall from my old Cub. It is a good idea to use a static port, rather than just leaving the instruments open to the air behind the instrument panel. Rarely does the cockpit ambient pressure match the actual static pressure, with the results that the instruments don't read accurately. But the location of this port must be carefully chosen to make sure it is not influenced by the airflow around the airplane. Putting the port out ahead of the lead edge of the wing, and well outboard of the propwash is usually a good choice. In the book "Flight Testing Homebuilt Aircraft" by Vaughan Askue (http://www.amazon.com/exec/obidos/tg/detail/-/0813813085/qid=1106857699 /sr=1-1/ref=sr_1_1/102-2003434-0024117?v=glance&s=books ) there is a whole chapter on selecting a location for the pitot-static system, and methods to calibrate it. Most pitot tubes don't read accurately at high angles of attack, generating airspeed readings considerably slower than the true airspeed. One of the tips he gives in the book is to chamfer the edges of the pitot tube, creating a slight funnel shape which tends to promote much more acurate indications. When I test flew my Pietenpol (with a chamfered pitot tube), I got an indicated airspeed at stall of about 42 mph. I was disturbed by comparing this to the speeds others were quoting (stall speeds as low as 29 mph), until I started running some calculations. For my plane to stall at 42 mph requires a maximum lift coefficient of about 1.8, whcih is quite reasonable for an airfoil made up by an amateur designer like BHP. For even a light weight Pietenpol to stall at 29 mph would require a lift coefficient of over 3.2, which is totally unrealistic without leading edge slats and double-slotted flaps. The only conclusion is that the airspeed indications are faulty and the actual airspeeds at stall are closer to 40 mph. Jack Phillips NX899JP -----Original Message----- --> Pietenpol-List message posted by: "Norman Stapelberg" Hello Fellow Piet pilots Thought I'd pass this one out there, went flying in my plane with the instructor, only to find that the air speed and VSI react as the power setting is changed, it seems I have a problem with the static port. I am currently using a pitot/ static tube, the static tube sits about 4" below the wing with the pitot tube another 2"lower. The front cockpit also has a ASI and Altimeter, these however are not connected to the pilots static system, the front Altimeter reads 100' higher than the rear cockpit, the ASI reads 10mph higher than the rear instruments. My thoughts are to plumb all the instruments to the static system, and then to use an alternate static port, my question is this where would the best place to pick up a reliable static position. To date we have flown 2hrs since the rebuild and everything else seems in order. Thanks Norman Stapelberg South Africa ZS-VJA (121hrs) ________________________________ Message 8 _____________________________________ Time: 01:34:46 PM PST US From: "walt evans" Subject: Re: Pietenpol-List: Static port --> Pietenpol-List message posted by: "walt evans" I took a shot at it, and guess got lucky. On the bottom of the rear instrument panel, made a fitting with a small hole in it, to put the static tube thru the ply, kind of down pointing at my right shin. No real variations, and airspeed checks with GPS. easy installation too, 12"of plastic tubing. Added a front ASI later and didn't add to the static system, and it has some variations. walt evans NX140DL ----- Original Message ----- From: "Norman Stapelberg" Subject: Pietenpol-List: Static port > --> Pietenpol-List message posted by: "Norman Stapelberg" > > Hello Fellow Piet pilots > > Thought I'd pass this one out there, went flying in my plane with the > instructor, only to find that the air speed and VSI react as the power > setting is changed, it seems I have a problem with the static port. > > I am currently using a pitot/ static tube, the static tube sits about 4" > below the wing with the pitot tube another 2"lower. The front cockpit > also has a ASI and Altimeter, these however are not connected to the > pilots static system, the front Altimeter reads 100' higher than the > rear cockpit, the ASI reads 10mph higher than the rear instruments. > > My thoughts are to plumb all the instruments to the static system, and > then to use an alternate static port, my question is this where would > the best place to pick up a reliable static position. > > To date we have flown 2hrs since the rebuild and everything else seems > in order. > > Thanks > > Norman Stapelberg > South Africa > ZS-VJA (121hrs) > >