I posted this on the Eagler's Nest forum and am purposely cross-posting it here on HBA. because we have quite a few folks here whose formal engineering education and experience is of great value to me. This is a rather serious structural question, regarding an original ("ultralight") Legal Eagle project airplane I own
The upper spar cap is supposed to be beveled at 5 or 6 degrees, and be flush with the top of the airfoil contour. On my airplane it is not beveled, and as such is not as large of a spar cap cross section area, in addition to the distance between the centers of the cap x-section areas not being quite as far apart.
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I removed the rest of the covering from my project airplane, and found something questionable. I would VERY much like to hear from the experienced folks here, whether they think this wing was built correctly or not.
The plans show the upper main spruce spar cap has a bevel, to match the airfoil contour. This allows the spar cap to be as tall as possible, and have as much "cross section" area as possible.
My airplane looks like it has a non-beveled square spruce spar cap, with the .8mm plywood glued on top of it, then non-structural wooden shims above that to match the airfoil contour.
This means there is less wood in the structural spar cap, as well as the spar not being as "tall" (distance between the spar caps) as it is shown on the plans.
I am interested in the opinions of any engineers or highly experienced LE people as to whether this wing construction is safe or unsafe and by how much.
The wood construction using T-88 is a little sloppy but completely solid. All glue joints appear to be shake-proof, no creaking, cracking or peeling.
The upper spar cap is supposed to be beveled at 5 or 6 degrees, and be flush with the top of the airfoil contour. On my airplane it is not beveled, and as such is not as large of a spar cap cross section area, in addition to the distance between the centers of the cap x-section areas not being quite as far apart.
-------------------
I removed the rest of the covering from my project airplane, and found something questionable. I would VERY much like to hear from the experienced folks here, whether they think this wing was built correctly or not.
The plans show the upper main spruce spar cap has a bevel, to match the airfoil contour. This allows the spar cap to be as tall as possible, and have as much "cross section" area as possible.
My airplane looks like it has a non-beveled square spruce spar cap, with the .8mm plywood glued on top of it, then non-structural wooden shims above that to match the airfoil contour.
This means there is less wood in the structural spar cap, as well as the spar not being as "tall" (distance between the spar caps) as it is shown on the plans.
I am interested in the opinions of any engineers or highly experienced LE people as to whether this wing construction is safe or unsafe and by how much.
The wood construction using T-88 is a little sloppy but completely solid. All glue joints appear to be shake-proof, no creaking, cracking or peeling.
