Stephens
Akro (Laser 200)
by Budd Davisson, courtesy of
www.airbum.com
People in the know speak
of the Stephens Akro in
hushed and slightly
fearful tones. It looms on
the aerobatic horizon like
the stranger come to town
to teach the Pitts boys a
thing or two about
aerobatics. Is it a Pitts
killer and is Leo
Loudenslager the man to
pull the trigger?
Let's make it clear right
now that I'm not the guy
to answer that question.
My name isn't Soucy,
Herendeen, Hillard or
Poberezny. Around the
airport, I'm known as
"Fumbles," and after an
exciting week when I flew
the Stephens Akro and the
180-hp symmetrical Pitts,
back to. back, I've
decided that I wouldn't
want to be in the ring
with any of the big guys
in either airplane.
America has finally popped
out on top of the
international aerobatic
pyramid for two reasons:
because of our pilots and
because Curtis Pitts
builds airplanes for us
instead of them. If we
didn't have the Pitts, we
probably wouldn't have the
Nestorov Trophy either.
Our team is a happy
combination of superpilots
flying superairplanes. But
nothing stands still in
competition, and since
it's hard to build better
men, improvement will come
in the form of better
machines. And if Clayton
Stephens has anything to
do with it, one of the
machines will be his
Stephens Akro.
According to the legends
filtering out of the San
Fernando basin, the Akro
exists because the late
Margaret Ritchie wanted to
beat Mary Gaffaney.
Actually, Mrs. Ritchie
wanted to beat everybody,
but her clipped-wing,
150-hp Taylorcraft just
couldn't cut the mustard.
Even with its big engine
and symmetrical airfoil,
it rolled too slowly and
had to pull around too
much fabric and tubing.
Clayton Stephens, an
aeronautical engineer
trying to add spice to his
aerospace career, came to
her aid with his slide
rule and drafting machine.
Since Stephens wasn't, and
isn't, an aerobatic pilot,
he had to do the entire
project with numbers and
formulas. He had no
prejudices or preconceived
ideas. He looked at the
maneuvers, studied the
airplanes, and designed an
airplane that broke the
At that point in time,
American aerobatic
tradition dictated using
two wings as the basis for
any aerobatic design. The
Akro, however, is a
monoplane.
Basically, the resulting
design resembled an
underdeveloped Formula One
racer. As a matter of
fact, part of the fuselage
layout is supposed to have
been inspired by Art
Scholl's old Miss San
Bernardino. In racing, the
midwing layout was
conventional, but in
aerobatics, it was
downright radical. If
throwing away one wing
didn't make the machine
unique in the world of
aerobatics, his airfoil
did-it wasn't symmetrical!
The modern development of
superaerobatic airplanes
requires that more and
more attention be paid to
outside manoeuvres. This
means the wing should lift
equally both ways, but the
Stephens' doesn't. The
airfoil is an old
favourite, the 23012. I
hate people who banter
airfoil numbers around,
but this time it's
important. The 23000
series airfoils don't lift
the same upside down as
right side up, so Stephens
climbed out on a limb when
it came to outside, or
negative G, manoeuvres.
The construction is
absolutely conventional
and straightforward. The
wing is plywood
covered-with a 24-foot,
7-ply railroad tie running
wing-tip to wingtip. The
fuselage is miles of
chrome moly and fabric. At
first glance, the
construction looks
deceptively simple, but
it's not. Laminating the
spar requires that the
builder construct a
clamping table, 24 feet
long and perfectly true.
It's not difficult, but
it's certainly not as
simple as whittling out
Pitts ribs and spars and
letting the flying wires
handle the problem of
strength. Since it's a
cantilever wing, you'd
better be right the first
time you build it, because
there's no way to rig out
any basement booboos once
you're finished. Any twist
in the wing is going to
make the airplane fly like
a cork-screw.
Although there are at
least six Stephens flying,
Leo Loudenslager's is by
far the most interesting
and most advanced. Leo is,
by his own admission, a
total airplane freak. "I
guess you'd have to say
somebody is crazy to spend
five years building and
rebuilding an airplane,"
he grins. "I could have
been much farther along if
I'd built a proven
machine, like the Pitts,
but the second I saw the
Akro, I knew this was it
for me."
Since he first started
building his airplane, Leo
has functioned as Clayton
Stephen's eyes and hands.
He has tested and modified
the airplane, advising
Stephens how the changes
affected his manoeuvres,
so plans could be changed
accordingly.
Walking around the
airplane, you are aware
that this is the
embodiment of "form
following function." The
lines are so angular as to
be harsh and the bubble
cockpit really is a
bubble, perched atop the
skinny fuselage as if it
were an afterthought. The
horizontal tail has
Buck-Rogers tip-plates
added only recently to
increase the elevator
effectiveness without
increasing the area.
The things trailing back
from the wingtips are
unnamed, but will probably
be known eventually as
LLLs (Loudenslager Line
Layers). He can squint out
at those weird looking
little mobiles and tell
when he's exactly vertical
or at 45 degrees. Contests
are won and lost on
angles, so it probably
won't be long before
everything from Citabrias
to Pitts start sprouting
these things.
The first part of my
checkout was aimed at
getting me in the cockpit.
I didn't want to walk on
the wing, so I had to
stand tiptoe on the step
and stretch my other leg
into the cockpit. Once I
was inside, Leo explained
things and mentioned that
the cockpit was tailored
for him, so I might find
things not exactly where I
wanted them. I saw what he
meant when I tried the
brakes. Because of a
previous modification that
lengthened the rudder
pedals, the brakes were
right up against the
bottom of the tank. I was
wearing a, pair of
square-toed boots and I
really had trouble with
the pedals.
I must've scared the pants
off Leo when I taxied to
the far end of the runway
and then disappeared for
10 minutes. On the way
down the taxi-way, that
big 200-hp Lycoming
dragged me along at 20
mph, even at idle. I'd try
for the brakes, but the
tailwheel was so sensitive
that giant stabs at the
brakes caused me to weave
all over the place.
Figuring fear was the
better part of valour, I
pulled the mixture and
coasted to the end of the
taxiway. I yanked my boots
off, sat them on the wing
and waited. Pretty soon
Leo came around the bend;
he was much calmer than I
would have been in the
same situation. With a
couple flips of the prop,
I was on my way again in
my stocking feet.
Visibility during run-up
and while checking for
traffic is fantastic. It
was as though I were
sitting on a bar stool on
top of the wing. The
cockpit isn't large enough
to do a lot of romping
around in, but it is far
from tight, and I didn't
even notice the main spar
passing over my legs. A
guy with longer legs or
more girth might find the
spar hitting him just
below the knees, though.
Leo had said not to worry
about torque on takeoff,
so I rammed the power in
fairly rapidly. He was
right. It tore down the
white stripe with very
little help from me. My
feet didn't even get into
the act, and I had barely
gotten the tail off the
ground when those long
wings reached out and
hoisted me up off the
runway. The acceleration
was fast, lightning fast,
compared to most
lightplanes, but it didn't
have the heart-stopping
surge of a Pitts. That
could be because I was up
and away in the Stephens
at something like 65 to 70
mph, while a Pitts usually
stays on the runway longer
than that.
And was I ever going up!
At 100 to 110 mph
indicated, the runway and
surrounding hills dropped
away so fast it was almost
frightening. On later
takeoffs, I tried to hold
90 mph and time the
climbs. They came out
around 2,700 to 2,800 fpm,
for at least a 30- to
40-degree angle. People on
the ground said they could
easily see the tops of the
wings as I climbed---it
climbs even faster than a
Pitts.
Except for the climbout,
so far I felt as if I were
strapped into a wildly
hopped-up Citabria. It had
been extremely stable and
had an unusually familiar
feeling. There was no
strange-airplane syndrome,
where everything is
unfamiliar and hard to get
used to. I felt as though
I'd had 1,000 hours in it
from the beginning.
In cruise, it hops along
at around 140 mph
indicated (150 mph true)
and handles like I'd hoped
it would. There isn't
anything among normal
airplanes that favourably
compares with it in
straight-and-level flight,
except possibly a Swift.
The control pressures are
light, lighter than a
Pitts when fully
deflected, but the stick
travel is much greater. A
little aileron calls for a
little stick, and a lot of
aileron demands a lot of
stick. It feels as if the
stick and the control
surfaces are directly
connected, without
linkage, because the
slightest movement of the
stick provokes an
instantaneous reaction.
Since the wing is nothing
more than an airfoiled
slab with little or no
dihedral, the airplane has
no particular reason to
stay in level flight, so
it gimbals effortlessly
about its centre of
gravity.
My total time in level
flight consisted of two
tight clearing turns in
either direction, before I
tucked the stick to one
side and watched the
horizon curl across the
top of the canopy in a
sensuous roll. From that
point on, I must have
looked like an aerial
otter; I'd flop through a
frantic series of
manoeuvres, stop for a
second, look quickly
around for traffic, then
start writhing around the
sky again.
In normal aerobatics, the
Stephens Akro is a damned
boring airplane. Loops,
rolls and the mundane
normal manoeuvres happen
with the precision of a
push-button machine. Pull,
and you loop. Stick to one
side, and you roll. Simple
as that. Leo has a grease
pencil X on the windshield
that you can fly like a
gun sight, and to keep
that exactly where you
want it demands only a
little more technique. It
makes sport aerobatics
almost too easy.
The second I pointed the
nose straight up, I could
see that the Stephens was
going to be a mean
airplane to beat in
competition. It seemed to
go uphill forever, and
vertical rolls were a
simple matter of putting
one of the LLL attitude
indicators on the horizon
and slamming the aileron
in. A little rudder and
stick action was all that
was needed to make the
wingtips rip around the
horizon. At first I was
banging the stick hard
against one leg, but I was
whizzing around so fast
that I would pass my
starting point, do a 1'/4
vertical and end up with
too much speed. I found I
could casually pull up
from 180 mph and do a
leisurely roll and still
have plenty of speed to
fly away inverted. From
around 200 mph, I was
trying to do vertical
four-points, not one of my
best
manoeuvres,
and I was amazed at how
easy it was to come
banging to a halt every 90
degrees, then start
rolling just as quickly,
heading for the next
point. Boy, does this
thing do vertical rolls!
The really surprising
thing about its vertical
performance is that it
doesn't pick up speed too
fast going down-hill. I
guess gravity works the
same for all airplanes,
biplanes or other-wise,
until aerodynamic drag
raises its fuzzy head and
.slows down the bi-planes
as they go past 100-120
mph.
On my first inverted
recovery out of a
hammerhead, I banged the
throttle a little too
hard, and the added
slipstream over the tail
made it so effective that
it felt as if the airplane
stood still while the tail
moved down. That was
probably one of the
squarest outside corners
I've ever made.
I don't know who said
semi-symmetrical wings
aren't supposed to work
inverted, but he was wrong
because the Stephens
doesn't know right side up
from upside down. The nose
attitude inverted is as
flat as a fritter, and I
had to really work to make
inverted turns without
gaining attitude.
As far as that goes, I
gained altitude no matter
what I did. I tried six or
seven outside loops before
I got one to come out at
the same altitude. I kept
gaining 300 to 500 feet in
each. The controls are so
incredibly effective at
slow speeds that I could
do half-outside,
half-inside square loops
with half rolls on each
leg, and still not be
going much over cruise
speed on the way down. I
tried to push up into a
full vertical roll from
inverted, but the top of
my head started to come
off so I chickened out.
The snap rolls are
blinding, blurring,
whirling affairs that
squeak to. a halt in an
instant. Basically, they
are simple: yank, stomp
and hold onto your hat. I
was snapping going up,
down, across, everyway.
The notes that come with
the Stephens plans say it
rolls at 180 degrees per
second, which is exactly
the same as a symmetrical
"round-wing" Pitts, but I
find that figure hard to
believe. The Pitts seems
faster than the Stephens.
Of course, once you're
rolling faster than about
150 degrees a second (most
aircraft are in the 60- to
90-degree range),
everything is a blur,
anyway.
Even though it was
unintentional, I did a
wild stall series in the
Stephens: straight up,
straight down, inside and
outside, as I fell out of
muffed
manoeuvres.
Whenever it stalled, I
felt as if I were standing
on a four-foot square of
plywood balanced on a
bowling ball. When the
wing unloaded, I never
knew for sure in which
direction it was going to
go. It has a sharp break,
but then mushes with one
wing dropping. Kicked into
a spin, it goes around
like a Fourth of July
pinwheel-faster, it seems,
than a Pitts and harder to
stop.
On the way down, I timed
the rate of descent at
approach speed (80 mph)
and found it to be around
800 to 900 fpm, about like
a Cherokee. What I
couldn't measure, and
didn't even notice until I
got into the pattern, was
the glide ratio. The
airplane is so clean that
it goes and goes. I shot
three or four landings,
making each pattern bigger
and bigger, and even with
no power, I ended up
slipping to get the thing
down. That's an area where
the Pitts definitely loses
out. A Pitts comes down
like a manhole cover with
a drag chute.
Landings are absolutely
beautiful, whether on the
mains or in a three-point.
The gear is exactly as
stiff as it should be, and
the tailwheel and rudder
are effective enough to
control, but not so
sensitive that they get
you in trouble. Since it
stalls at around 50 mph,
you can be on the ground
at a near walk, with a
clear view in front of you
at all times. It's almost
like landing a Cessna 150.
On my last landing, I
still doubted my ability
to get the brakes on
without damaging my
bunions, so I cut the
mixture as soon as I
touched and rolled to a
halt. As I pulled the
canopy open, Leo trotted
up grinning. All I could
say was "Doesn't this
thing do anything wrong?"
You're probably begging me
now to say, "Yes, it's
better than a Pitts," or
"No, the Pitts is still
king." But I'm not going
to say either, and I'm not
copping out. The Stephens
and the Pitts each has its
own character and
manoeuvres at which it
excels. In the Pitts, for
instance, it takes some
work to figure out how to
hammerhead properly, but
once you get the hang of
it, it pivots as it you've
driven a nail through the
rudder post. The Stephens
won't pivot that way. It's
an easier airplane for the
new pilot (me) to control
because the control ratios
are longer, requiring more
input per
manoeuvre,
which makes it less
twitchy looking. They are
two different airplanes,
so they are bound to fly
differently.
When all is said and done,
it comes back down the
pilot. There aren't 20
pilots in the U.S. who
would be able to
capitalize on the
difference between the two
airplanes-they are so
closely matched. I think,
though, that the two would
make pilots develop
different styles; the
Pitts encourages a quick,
zippy sequence, while the
Stephens evokes a smooth
and ballet-like
performance. But, either
airplane is capable of
doing everything the other
can, and either will eat
the European machines
alive. Put a champion in
either airplane and he
would still be a champion.
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