I'm trying to find this information for commercial jets. It is nowhere to be found. Does anyone know typical values?
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$\begingroup$ Do you mean the built in wing twist to adjust for lift distribution across the wing, or the induced twist that can occur when making use of your ailerons? $\endgroup$– NoddleSep 8, 2021 at 15:14
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$\begingroup$ @Noddle Built in wing twist. $\endgroup$– stevederekson555Sep 8, 2021 at 15:30
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2$\begingroup$ This is usually called wing washout or washin (depending on which way it twists), which may help your search $\endgroup$– DanSep 8, 2021 at 20:05
2 Answers
For an A310 we start from the attack of the engines with an angle of attack of the profile of 3 degrees, and we arrive at the wing tip to -3 degrees. In general along the wing the twist angle is around 2-3 degrees, it is near the tip that changes and arrive until a negative value.
Commercial jets are special because they change airfoil shape over span quite dramatically to reduce the effects of sweep on local lift. Also, the lift force on a backward swept wing causes it to twist, so washout in flight is several degrees higher than on the ground.
In order to compensate for the much higher zero-lift angle of attack of the modified root airfoil, its incidence is very high. If you use the fuselage axis as a reference, in case of the A330 and A340 the incidence changes from +4.5° at the root to 0° between 30% and 70% span and -2° at the tip when on the ground and -2° at 70% span and -5° at the tip in flight.