Maneuvering Va

Everywhere I “go,” there’s a lot of talk among student pilots about Maneuvering Speed: what it means, why it’s necessary to know what it is, why it doesn’t appear on the airspeed indicator, and why it reduces in value with reduced weight.

I’ve heard (and read) explanations aplenty utilizing such ideas as angle-of-attack, the increasing or decreasing distance between “flying aoa” and “critical aoa,” wing-loading, designed load-limits, and even manufacturer-imposed limits on elevation travel!

All these have contributed more to confusion than comprehension and I can just imagine what combination of bizarre answers given over the years when asking the student pilot the natural follow-up question (after definition) about why Va reduces with reduced weight. It serves to show, I think, how unnecessarily complicated we make things. No two texts seem to have the same answer beyond the nominal definition of the speed, although they are all correct! The ultimate dilemma (trilemma, quadrilemma?)

Here it is, simple and easy, once and for all:

Maneuvering speed is the stall speed of the aircraft at design load limit and just as with any other stall speed, it is reduced at reduced weight.

This beautiful explanation is courtesy of Rich Stowell’s book—and a few forum posts here and there:

in which he quite effectively tackles all of this in terms of the V-n (or V-g) diagram.

(This post is in honor of my recently departed cat, Cessna. Clear skies and tailwinds, dear girl!)

Excelsior

Florida Atlantic University, Boca Raton, FL.

A rather disappointing college—if you wanted to study Aeronautical Engineering—seeing as they didn’t have such a department. For some reason, they did have a department of Ocean Engineering. Why, I have no idea! It’s not like the school was less than a mile from the Atlantic ocean or anything and that it had the actual word ‘Atlantic’ in its name. Whatever.

So I didn’t end up studying my first love and so, I never got to fulfill a childhood dream: designing, building, and flying an aircraft of my own design. Maybe I’d have been this guy, Dave Rose:

Dave-Rose-RP4

That’s a machine he calls the RP-4. Jeff Wise writes up a pretty entertaining article in Popular Mechanics about him and others who fly aircraft of their own designs. The RP-4 is being built to either kill Dave Rose or catapult him into aviation glory for the fastest piston-power aircraft (something around 529mph)

Rules of Thumb?

I wonder how precisely it is possible to calculate this little rule of thumb: “10–25° flap add more lift that drag. 25–40° flaps add more drag than lift.”

I once read that when the flaps are at the same degree of deflection as the aileron is when also deflected, the pilot gets the highest amount of left from the flaps. I think my batty instructor told me that before slamming home his shot of tequila (eight hours before he flew again, of course).