What is the difference between buffeting and fluttering?
The vernacular meaning is...

1) Flutter is un-commanded self perpetuating (positive feedback) destructive &amp; adverse cyclic movement of any part of an aircraft. It most commonly occurs on a control surface but may be an entire wing, tail surface, or more rarely fuselage or other part or device. Flutter may be induced either mechanically or aerodynamically and may be sustained mechanically (i.e. engine or prop, landing gear or ground resonance of a helicopter skid) or aerodynamically by self perpetuating (positive feedback) force. Mechanical inception can be (but not limited to) brisk or pilot induced oscillation, weak, unsupported, or flimsy structures. Aerodynamic inception can be (but not limited to) undesirable cg, or aerodynamic forces on parts. Flutter is always undesirable, dangerous and a destructive force.

2) Buffeting is a turbulent stream of air striking any part of the airframe. The turbulent air may be completely external (weather) or created by the aircraft it self (prop, wing,etc). The most common form of buffeting is turbulent airflow over a wing (i.e. during a stall or wind gusts) striking the wing or horizontal tail. Buffeting is not usually considered self perpetuating with positive feedback, nor is it considered to be precisely cyclic or harmonic - though it may be repetitive. Buffeting is usually considered undesirable but benign and not a destructive force.