The air was smooth as glass, and I had the traffic pattern to myself. It couldn’t have been better—right up until the time I retracted the landing gear. As soon as the gear was up, the Baron began to violently shake and shudder. I noticed that it wasn’t just the aircraft that was shaking; the control yoke itself was oscillating in my hand, separate from the rest of the aircraft. My attention shifted to the control surfaces, and I swiveled around in my seat to give them a close look. Then I saw it...