Regarding the Mi-24 wing symmetry:
The Mi-24 wing is assymmetrical in that there is typically a 1.5 to 2.0 deg difference in wing incidence, with the higher incidence on the right wing, as I recall. So, that would yield 17.0 deg on the left & 18.5 to 19.0 deg on the right, for example. Reference to this wing assymmetry can be found in Practical Aerodynamics of the Mi-6 Helicopter, by M. S. Yatsunovich, Moscow Transport, 1969. Also, in Helicopters - Calculation & Design Vol 1. Aerodynamics, by Dr. Mikhail L. Mil, et al, Moscow 1966.
While there may be some deviation in wing incidence from Mi-24 variant to variant, due to minor design changes, or mission requirements, the general rule still applies. In some cases, I would expect, the incidence could be as high as 21.5 deg, or so. Therefore, I cannot say that all Mi-24 variants necessarily have the same wing incidence, only that the Soviet design practice of employing 2 deg, or so, of differential incidence on their winged helicopters was typical & documented.
