Flight Training - May 2021 - 32

JARGON

Critical angle
of attack

Knowing your airplane's
straight-and-level " stall speed "
for training flights is all well and
good, but aerobatic training will
drive home an important point:
Stalls can happen at any airspeed
and any pitch attitude. What's
important is the wing's angle of
attack, the angle between the
wing's chord and the relative
wind. Once it exceeds its critical angle of attack-whether
in slow level flight or pulling up
from a high-speed dive-the wing
loses lift and stalls.
aopa.org/ft/attitude

Spin recoveries can be jarring since
the airplane is typically in a steep dive
of about 70 degrees. At this point, the
student should neutralize the rudder, pull
out of the dive, and add engine power to
maintain flight.
Spins are inherently nauseating, so
instructors have to be careful not to overdo
them. Also, students need time to process
the novel sights and sensations, so they
should be given a break. But the downtime
is invaluable. Students bewildered by spins
on their first flight often perform them
with precision and ease the next day.
Spins have always had a fearsome
reputation. They're the schoolyard bully
of aviation. But once confronted, aerobatic
students realize that, just like bullies,
spins aren't so tough after all.

Common student errors:

* Failing to apply and hold full pro-spin
inputs throughout the maneuver.
* Losing orientation as the spin
accelerates.
* Holding recovery rudder too long after
the spin rotation stops.
ROLLER COASTER RIDE

The loop introduces aerobatic students to
high-G forces, and it teaches them to look
around for the horizon to maintain their
orientation.
A loop typically begins at a relatively
high speed and full engine power with
wings level. A firm pull on the stick (ideally about 3.5 Gs) starts the initial climb.
As the nose rises well above the horizon,
the pilot must look left or right for the
horizon to stay oriented. And as airspeed
diminishes near the top of the loop, the
pilot must ease back-pressure on the stick
and " float " over the top at or near zero Gs.
At the apex of a loop, the pilot should
look overhead to reacquire the horizon,
then straight ahead on the back side of the
32  FLIGHT TRAINING MAY 2021

loop as the airplane builds
speed in the dive. A firm
pull on the stick (3.5 Gs
again) brings the airplane
back to level flight-ideally at the same speed and
altitude that the maneuver
began.
The combination of high
Gs at the bottom of the maneuver and weightlessness at the top
makes the loop feel like a roller coaster
ride. The lessons it imparts are the ability
to maintain orientation throughout 360
degrees of pitch and a wide range of airspeeds and angles of attack.
The loop begins at high speed-typically in or near the yellow arc on the
airspeed indicator. At the top of the
maneuver, the airspeed drops to near
(and sometimes well below) the power-off
stall speed.

Common student errors:

" Too many cadets before you have
come to grief because they were 'carried
away' by their enjoyment of aerobatics
and a desire to become aerobatic experts.
The Navy does not expect them to become
skilled stunt pilots. "
Then, as now, the benefits of aerobatic
knowledge were well known.
" Aerobatics are part of the primary
syllabus for only three reasons: 1) to teach
a pilot to remain oriented in any attitude which the airplane may assume. 2)
Because they require more elaborate and
speedier manipulation of the controls,
they greatly improve coordination. 3)
To increase a pilot's confidence both in
himself and in the airplane-only after
he is once convinced that he can put
the airplane in any possible attitude and
recover to normal flight will he lose his
last lingering fear of flying. " FT
dave.hirschman@aopa.org

* Losing orientation during the initial
climb as the horizon disappears under the
nose.
* Pulling too hard at the top of the loop
when airspeed is critically low.
* Pulling too soon in the dive and exceeding the critical angle of attack.
TAKEAWAYS

Aerobatic training allows pilots to think
and fly in all three dimensions. The use of
full control deflection is no longer taboo,
and aerobatic pilots don't hesitate to use
it during crosswind landings, unusual
attitude recoveries, or other situations
that call for it.
Practicing spins and accelerated
stalls gives aerobatic students an appreciation of where the critical angle of
attack resides. They recognize it, and can
come close to it without exceeding it.
That's a big help when making shortfield approaches and landings, or flying
heavy airplanes at high density altitudes.
In instrument conditions or turbulence, a momentary aircraft upset isn't a
life-threatening emergency to a pilot with
aerobatic training. It's just an unusual
attitude that they've seen before, recognize, and know how to recover from.
The downside of aerobatic flight
training was pointed out long ago. In a
1945 U.S. Navy flight training manual, the
author pointed out that pilots tend to like
aerobatic flying so much that it's the only
kind of flying they want to do.

GameBird designer Philipp Steinbach shows
off the unlimited aerobatic airplane's ability
to maintain inverted flight. A fuel-injected
engine and a specialized oil system allow
the Lycoming engine to keep producing
power during sustained inverted flight.
http://www.aopa.org/ft/attitude
Flight Training - May 2021

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