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 02.12.06
Most Instrument Flight Rules (IFR) procedures are built around
what’s called a "Standard Rate Turn." Standard Rate (SR) is
also an easy turn for pilots wanting to give passengers a smooth
ride. SR is three degrees of turn per second, which requires two
minutes to complete a full circle (Note: some old-timers refer to
Standard Rate as a "two minute turn.")
Since this is a rate of turn, SR is a function of bank angle and
True Air Speed (TAS). You can approximate the bank angle (in
degrees) required for SR as 15% of the TAS (in knots). If your TAS
is 90 knots (a common IFR approach and holding speed) it’ll
take about a 14 degree bank to result in SR (90 ÷ 10 = 9 +
half of 9 = about 14). At 120 knots TAS SR requires about 18
degrees bank (120 ÷ 10 = 12 + 6 = 18); at 180 KTAS standard
rate requires about 27 degrees of bank.
You don’t have to do the math every time -- your airplane
will have two main SR bank angles, one at cruise speed, the other
at approach (which is also close to climb speed).
Why is this important, especially when turn coordinators and
turn-and-bank indicators have a marker that shows a standard-rate
turn? Fixation on this secondary instrument, especially when
rolling into a turn, may result in an altitude excursion if the
pilot is distracted from pitch control. I teach watching the
attitude indicator when rolling into a SR turn, establishing the
required bank angle while simultaneously maintaining pitch for
altitude control. Only after establishing bank do I cross-check the
turn indicator, and fine-tune bank as necessary.
This knowledge is extremely helpful in partial-panel flight
also. Knowing that SR turns require a very slight bank reminds
pilots to avoid big control movements if primary attitude guidance
fails.
(ABOVE: Turn Coordinator with "Standard Rate"
Markings)
Aero-tip of the day: Know the bank angle required to obtain a
Standard Rate turn, for precision and the ability to better control
a "partial panel" airplane.