Bank Angle In The Circuit
Posted: Mon Jul 30, 2012 5:58 am
Longtime readers of AvCan will cringe now and stop reading.
A pet peeve of mine for many, many years is what horrible
nonsense flight instructors in Canada teach their students
about bank angle in the circuit.
Decades ago, someone (long since retired, or dead) noticed
that as bank angle increased, so did stall speed. So, to avoid
stall/spin in the circuit, it was announced with near-religious
fervor that henceforth minimum bank angle would be used
in the circuit. Great celebrations followed, with banquets
and awards, and not just the cheesy ribbons - I'm talking
metal and wood trophies.
Small detail. It is only true that stall speed goes up with
bank angle if you are pulling more and more G which is
a result of a LEVEL turn with the BALL IN THE CENTER.
For example, I can safely turn base in almost any aircraft
at 60 degrees of bank (ok, 59.99999999 degrees) at
slow speed as long as the G is very light - the wing is
not working, and hence has a low angle of attack) and
especially if I sideslip.
Remember, slips are good. Skids are bad. I will frequently
use 90 degree sideslip on short final to kill energy, and
my aircraft does NOT explode with infinite G as your
ab initio instructor taught you, because the ball is not
centered, and I am not maintaining altitude.
The above is really important to understand.
Anyways, I was flying with another victim of our flight
training establishment yesterday. He would turn base
with a very shallow bank angle as he was taught, but
unconsciously, to speed up the turn, he would hoof
the inside rudder (a skid) and then as the inside wing
dropped due to loss of lift, try to pick it up with aileron
creating more adverse yaw, which of course aggravates
the spin entry.
He really didn't want to enter a spin turning base or final,
he was just doing what generations of unthinking flight
instructors have parrotted down through the decades -
keep the bank angle low.
This is all totally and completely wrong.
What matters in the turns is NOT keeping the bank angle
low, but maintaining airspeed and keeping the ball centered.
I have a mantra for light trainers for maneuvering in
turns after downwind, until wings-level on final:
80 and ball
If you maintain 80 mph with the ball centered, you can
use 60 degrees of bank during turns onto base and final
without stalling or spinning. Check your POH. This is
helped by the fact that you are NOT trying to maintain
altitude during these turns.
Most people are very very uncomfortable with excessive
bank angle in the circuit - they will NOT willingly use 60
degrees.
But the good thing about bank angle is that YOU CAN SEE
IT! You often can't see a nasty skid unconciously caused
by inside rudder - see Illusions Created by Drift.
So please, flight instructors in Canada, break the cycle. Stop
teaching your students to fly dangerously and badly. Bank
angle in the circuit is NOT evil - what's evil are skids!
A pet peeve of mine for many, many years is what horrible
nonsense flight instructors in Canada teach their students
about bank angle in the circuit.
Decades ago, someone (long since retired, or dead) noticed
that as bank angle increased, so did stall speed. So, to avoid
stall/spin in the circuit, it was announced with near-religious
fervor that henceforth minimum bank angle would be used
in the circuit. Great celebrations followed, with banquets
and awards, and not just the cheesy ribbons - I'm talking
metal and wood trophies.
Small detail. It is only true that stall speed goes up with
bank angle if you are pulling more and more G which is
a result of a LEVEL turn with the BALL IN THE CENTER.
For example, I can safely turn base in almost any aircraft
at 60 degrees of bank (ok, 59.99999999 degrees) at
slow speed as long as the G is very light - the wing is
not working, and hence has a low angle of attack) and
especially if I sideslip.
Remember, slips are good. Skids are bad. I will frequently
use 90 degree sideslip on short final to kill energy, and
my aircraft does NOT explode with infinite G as your
ab initio instructor taught you, because the ball is not
centered, and I am not maintaining altitude.
The above is really important to understand.
Anyways, I was flying with another victim of our flight
training establishment yesterday. He would turn base
with a very shallow bank angle as he was taught, but
unconsciously, to speed up the turn, he would hoof
the inside rudder (a skid) and then as the inside wing
dropped due to loss of lift, try to pick it up with aileron
creating more adverse yaw, which of course aggravates
the spin entry.
He really didn't want to enter a spin turning base or final,
he was just doing what generations of unthinking flight
instructors have parrotted down through the decades -
keep the bank angle low.
This is all totally and completely wrong.
What matters in the turns is NOT keeping the bank angle
low, but maintaining airspeed and keeping the ball centered.
I have a mantra for light trainers for maneuvering in
turns after downwind, until wings-level on final:
80 and ball
If you maintain 80 mph with the ball centered, you can
use 60 degrees of bank during turns onto base and final
without stalling or spinning. Check your POH. This is
helped by the fact that you are NOT trying to maintain
altitude during these turns.
Most people are very very uncomfortable with excessive
bank angle in the circuit - they will NOT willingly use 60
degrees.
But the good thing about bank angle is that YOU CAN SEE
IT! You often can't see a nasty skid unconciously caused
by inside rudder - see Illusions Created by Drift.
So please, flight instructors in Canada, break the cycle. Stop
teaching your students to fly dangerously and badly. Bank
angle in the circuit is NOT evil - what's evil are skids!