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 good pilots, we're all in this
together.
Aero-Tips 03.18.06
Add power and you need right rudder to track a straight line.
Raise the nose to climb and you need right rudder to maintain
coordinated flight. Why specifically do you need right rudder? Are
there any times when left rudder is required to track a straight
line?
Feel the Force
What’s correctly called the "left-turning tendency" of
propeller-driven airplanes stems from four interrelated forces:
- Torque reaction. For every action there’s an equal
and opposite reaction. As internal engine parts and the propeller
rotate one direction, the airplane tends to roll the other. Many
airplanes have engines mounted slightly off center to help
compensate.
- Corkscrew effect. Air off the propeller corkscrews
around the fuselage and, in most designs, impacts the left side of
the vertical stabilizer, pushing it right and the airplane’s
nose left.
- Gyroscopic loading. A rotating propeller is like a
gyroscope. Spinning gyros exert force at 90? to the plane of
rotation, which in airplanes means a yaw to the left.
- P-factor. Asymmetric loading of the propeller means more
thrust is created on the down-moving, right propeller blade. This
added force drives the airplane’s nose to the left.
Adding power increases all four factors. Raising the nose
increases factors (3) and (4). Add power and raise the nose at the
same time, like in a go-around or missed approach, and it’ll
take careful rudder control to avoid turning to the left.
Left Rudder?
Are there times when it takes left rudder for coordinated
flight? Sure. Reduce power to idle, or put the nose of the airplane
down, and it’ll take left rudder to keep the turn
coordinator’s ball centered. This is obvious in a Cessna 172
in a descent, or any airplane practicing Lazy 8s. Another case when
left rudder is required for coordination is when the airplane out
of rig, not terribly unusual as the fleet ages.
And of course, if the engine and propeller rotates the other
way, as in most European-designed engines like that in an
Australian friend’s Tiger Moth biplane, all the factors drive
the airplane’s nose to the right, requiring left rudder for
coordination.
Aero-tip of the day: Do what it takes to keep
the ball in the center, but you can usually predict which foot will
have to do most of the work.