Infographic

I’ll be honest. Writing this month’s column about engine data as thousands continue to die from the virus seemed – trivial. Then two things came to mind. First, you’re probably reading this to get a short break from the news. Second, so much of...

Hot Seat

Is it legal to install uncertified equipment in a certificated aircraft? I receive and answer hundreds of emails each week from aircraft owners, pilots and mechanics who have maintenance-related questions. One I received several weeks ago seems worth sharing: Mike, I...

Magnetude

If you can have latitude in your attitude, then a properly-timed set of mags can have – magnetude. I guess it can have magnitude, too, but this column’s about the good, bad and ugly of mags and ignition spark. The EGT pattern of a perfect mag check can be...

Risky Business

Why it’s nearly impossible to install a cylinder properly when the engine is on the airplane. Cylinder replacement is a highly invasive and risky procedure with a long history of causing catastrophic in-flight engine failures that cause airplanes to fall out of the...

Untold Riches

The flip side of a cylinder running too lean is one that runs too rich. If it’s too lean the usual suspect is an injector clog for those with injectors or an induction leak for carbureted engines. When it’s too rich it’s often because of something...

Shear Joints

When using fasteners loaded in shear, things can get interesting. The wing of the B-17 is attached to the fuselage by three bolted shear joints. Last month, I wrote about joints involving threaded fasteners loaded in tension—that is, along the bolt’s longitudinal...

Tense Bolts

When using threaded fasteners in tension, it’s all about the preload. Tightening a cylinder hold-down nut is an extraordinarily critical task. Failure to do it exactly right can result in catastrophic engine failure. Threaded fasteners are ubiquitous in aviation. Look...

The Seebeck Effect

The Estonian physicist Thomas Johann Seebeck died a couple of generations before the Wright Brothers demonstrated powered flight. Each December I remember to thank the brothers from Dayton for their courage and persistence that eventually led to the gift of aviation...