We took over a project and are concerned about airfoil twist.
Measured from 3 points: LE root, LE tip, TE root all on the same plane,
the TE tip is 0.60 inch elevated (twist)
Based on the info in Don Dykins' book (constant 1.5 degree twist) and
the formula:
Twist (inches)=chordx(sin 1.5deg)
We get a spec of 1.0 in twist@40in chord. This gives us about 0.9deg
twist.
This spec gives me pause and may indeed be dangerous at stall.
Remember, we are talking about a classic wing here.
What have other classic builders discovered as their actual twist
values?
What has been done to compensate/remedy the situation?
I would hate to have to throw these wings away.
Creighton Smith
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