This is a little know fact, as they try to keep the whole "bang balance" thing hushed up. During "C" checks, they have several people with little rubber mallets pore over the entire fuselage and wing surfaces to even out "bangs" caused by luggage wheels, hail, mishandled baggage carts... until the plane is in "bang tune" condition. Only properly certified "bang balancers" are used, of course, and that highly demanding ability is an additional specialized skill subset and endorsement to their A&P certifications; you can tell them by the "arm and hammer" logo on their licenses.

Thanks for making it a better, more humerus Friday!