Aero-Tips!

A good pilot is always learning -- how many times have you heard this old standard throughout your flying career? There is no truer statement in all of flying (well, with the possible exception of "there are no old, bold pilots.") It's part of what makes aviation so exciting for all of us... just when you think you've seen it all, along comes a scenario you've never imagined.

Aero-News has called upon the expertise of Thomas P. Turner, master CFI and all-around-good-guy, to bring our readers -- and us -- daily tips to improve our skills as aviators, and as representatives of the flying community. Some of them, you may have heard before... but for each of us, there will also be something we might never have considered before, or something that didn't "stick" the way it should have the first time we memorized it for the practical test.

It is our unabashed goal that "Aero-Tips" will help our readers become better, safer pilots -- as well as introducing our ground-bound readers to the concepts and principles that keep those strange aluminum-and-composite contraptions in the air... and allow them to soar magnificently through it.

Look for our daily Aero-Tips segments, coming each day to you through the Aero-News Network. Suggestions for future Aero-Tips are always welcome, as are additions or discussion of each day's tips. Remember... when it comes to being better pilots, we're all in this together.

Aero-Tips 04.07.06

You know about the Bernoulli principle and how Newton's laws apply to lift.  But have you ever heard of the Magnus Effect?

The Magnus Effect can best be visualized by looking at a cylinder rotating in an airstream.  The local air velocity near the cylinder is composed of the airstream velocity plus the cylinder's rotational velocity -- a boundary layer of air means local velocity is lower the farther air is from the cylinder.  If the top of the cylinder is rotating in the same direction as the airflow, local velocity on the top is higher than local velocity on the bottom.

There's a stagnation point at the level where air flows either up or down around the cylinder.  A second stagnation point exists behind the cylinder where air paths rejoin.  There's an upward flow ahead of the cylinder and downward behind it.

Under (and over) pressure

This difference in flow results in lower pressure on the top of the cylinder than on the bottom.  This in turn causes an upward force called…the Magnus Effect.  It's the same force that causes a baseball to curve, or a golf ball to slice.

An airfoil with a positive angle of attack creates airflow circulation as the wing's sharp trailing edge forces the aft stagnation point aft of the wing, while rebounding from the leading edge forces the forward stagnation point ahead of the wing. 

Aero-tip of the day:  Next time someone asks you to explain how a wing develops lift, remember Bernoulli, remember Newton…and don't forget Magnus.

FMI: Aero-Tips