Archive | August, 2013

Sharpen the Axe

Abraham Lincoln is the source for many variations of the following quote: If I have only a day to cut down a tree, I will spend the first half of it sharpening the axe. Jeff Olson adds to that analogy: How you swing the axe, how hard, in what arc and with what rhythm on […]

What is landing gear shimmy?

What is shimmy? It is an unstable lateral/yaw oscillation in a landing gear. This NASA video shows shimmy testing at Langley, and in it, you can see the lateral movement and twisting modes developing. Here’s what one presentation describes: “Among the various components that make up an aircraft, the landing gear is an important and […]