Induced drag increases as the airplane slows down and the angle at which the wing meets the air increases ... a relatively thick airfoil section, recessed ailerons, and a cantilever structure ...

The twisting caused one end of the wing to have more lift and the other end to have less lift. To produce the same effect, modern planes use ailerons ... cause the aircraft to spin out of control.

“Postaccident examination of the airplane revealed that the left wing extension and the left aileron were substantially damaged,” said the NTSB in the report. “The left wing ...