Pattern wing profile question
#1
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From: Montreal, CANADA
I have an old Pattern plane (70's design) that I am putting together. It's a old glass fuse and foam-core& balsa skin (it's a NO name plane)
the wing has a positive angle of attack (typical low wing config) AND it seems to have NOT a symmetrical profile and NOT even a flat bottom profile BUT rather the opposite! the wing seems to have been designed upside-down.... it's not totally flat top rather some semi-symmetrical shape with the more pronounced curvature on the BOTTOM of the wing!
to my knowledge the angle of attack will make the plane take off, but the faster it will go, the more down force will be generated by the upside-down profile of the wing.... is this supposed to compensate for the angle of attack of the wing itself? does it work well? I know the plane flies (have seen the prototype fly back in the seventies) but don't know how well it's going to fly, and am worried a bit because the plane was designed by a local club member.....
Can anyone help? with some comments on the design /configuration?
thanx,Vasek
the wing has a positive angle of attack (typical low wing config) AND it seems to have NOT a symmetrical profile and NOT even a flat bottom profile BUT rather the opposite! the wing seems to have been designed upside-down.... it's not totally flat top rather some semi-symmetrical shape with the more pronounced curvature on the BOTTOM of the wing!
to my knowledge the angle of attack will make the plane take off, but the faster it will go, the more down force will be generated by the upside-down profile of the wing.... is this supposed to compensate for the angle of attack of the wing itself? does it work well? I know the plane flies (have seen the prototype fly back in the seventies) but don't know how well it's going to fly, and am worried a bit because the plane was designed by a local club member.....
Can anyone help? with some comments on the design /configuration?
thanx,Vasek
#3
I'm with Huber on this one. That's just WRONG. I'm assuming you have the landing gear cutouts on the side of the wing with the more curvature and that is what you are basing this on? Does the fuselage wing mounting have the same shape to it or is the wing a poor fit?
I'm wondering if a) the landing gear cutouts were put on the wrong side of the wing in error or b) the wings have taken on a new set from being stressed in the kit box over the years from either internal box pressure or from being loaded under some outside stuff in it's past.
To the best of my recollection all the pattern models used symetrical airfoils by that time in history.
I'm wondering if a) the landing gear cutouts were put on the wrong side of the wing in error or b) the wings have taken on a new set from being stressed in the kit box over the years from either internal box pressure or from being loaded under some outside stuff in it's past.
To the best of my recollection all the pattern models used symetrical airfoils by that time in history.
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From: St. Charles, MO
Any chance of seeing a photo of the fuse, wings, etc. A lot of us were young when those days were in their heyday (what ever that means). We might recognize it from the photos and be able to help. I pretty well memorized everything that flew back then and have to agree with the other guys.
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From: Montreal, CANADA
thanx to all for the feedback [8D]
I did re-check the wing and it's not as bad as I saw it the first time, at the tip and most of through the mid-section of the wing is symetrical.... however at the wing root, the trailing edge sweeps upwards a bit (that's what i noticed at first)
I checked with the fuse cut-outs for the wing (thanks to Matt) and it fits nicely, except the end portion (the trailing edge).... I noticed that when the aileron torque rods were installed, the trailing edge was glued back at a slight angle (upwards) more over each wing has a little angle difference. I decided to cut the trailing edge off (up to the torque rods) and use a new aileron piece thus using the end pieces to glue on the root to match the "new" aileron. this will shape the wing to match better the fuse and conform to the intended wing section...
thaks to all for great info,
Vasek
I did re-check the wing and it's not as bad as I saw it the first time, at the tip and most of through the mid-section of the wing is symetrical.... however at the wing root, the trailing edge sweeps upwards a bit (that's what i noticed at first)
I checked with the fuse cut-outs for the wing (thanks to Matt) and it fits nicely, except the end portion (the trailing edge).... I noticed that when the aileron torque rods were installed, the trailing edge was glued back at a slight angle (upwards) more over each wing has a little angle difference. I decided to cut the trailing edge off (up to the torque rods) and use a new aileron piece thus using the end pieces to glue on the root to match the "new" aileron. this will shape the wing to match better the fuse and conform to the intended wing section...
thaks to all for great info,

Vasek




