Assertion: airfoil's angle | /r/HasProperty | changed
Facets:
Source sentences:
text: Nonsymmetrical airfoils were not used in earlier helicopters because the center of pressure location moved too much when angle of attack was changed.
text: Nonsymmetrical airfoils were not used in earlier helicopters because the center of pressure location moved too much when angle of attack was changed.
text: Non symmetrical airfoils were not used in earlier helicopters because the center of pressure location moved too much when angle of attack was changed.