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.
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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 04.28.06
I’m fascinated
with helicopters. I even considered joining the National Guard
after my stint in the Air Force, just to qualify in rotary-wing
aircraft (side note: the Guard wanted me to attend Warrant
Officer School even though I was an Air Force captain. I understand
the need for indoctrination, but basic training is something you
should only have to do once in a lifetime).
I don’t know why, but the concept of a helicopter flying a
"fixed-wing" instrument approach procedure struck me as odd.
Couldn’t a helicopter simply park itself over the missed
approach point and descend at a very low rate until breaking out or
(if the MAP was over the prepared surface) until actually touching
down? Such a thought, of course, stems from my ignorance of
rotary-wing aerodynamics.
Helicopter approach procedures
As it turns out, however, the unique attributes of helicopters
do permit lower instrument approach minima than fixed-wing
airplanes flying the same procedure. Aeronautical Information Manual (AIM) section
10-1-2 explains that...
- Helicopters flying conventional (non-Copter) instrument
approach procedures may reduce the visibility minima to not less
than one-half the published Category A landing visibility minima,
or 1/4 statue mile visibility/1200 RVR, whichever is greater.
Why? Because helicopters may not be able to "descend vertically
over the MAP" like I earlier thought, but they can fly much slower
than fixed-wing airplanes, and may be able to pull into an
out-of-ground-effect hover if needed... fixed-wing pilots, imagine
being able to "stop and think about it" inside the outer
marker!
- No reduction in MDA/DA is permitted.
Minimum Descent Altitude (MDA) and Decision Altitude (DA, often
referred to as Decision Height) are not negotiable because they are
obstacle-clearance minima. Even at a helicopter-ishly slow speed
you don’t want to run into the ground or a tower.
Aero-tip of the day: If like me you’re
not a rotary-wing pilot, the most important thing to learn from
special helicopter approach procedures is that a report a
helicopter has landed out of a low-IFR approach does not
necessarily mean conditions are good enough for a fixed-wing
airplane.