Bulging Biplane Biceps
What do you get when you take any airplane and more
than double the horsepower? For one thing you get much bigger grins every
time you move the throttle forward for takeoff. The 450 Stearman, the
so-called “Super Stearman,” is a classic case in point.
Originally born with a puny 220 hp, W-670 Continental radial in the nose,
when the airplane is given a noseectomy and an R-985 Pratt and Whitney
with 450 fire-breathing horses is grafted on, the airplane develops an
entirely different personality. What had been a leisurely school marm
intent on teaching a military cadet the very basics of aviating, becomes
a belligerent show-off eager to demonstrate what it can do.
The 450 Stearman HAD to happen. Right after World War Two, there were
literally thousands of both Stearmans and BT-13 Vultee trainers sitting
around for bargain basement prices. The Stearmans were ideal for crop
dusting, although underpowered, but the Vultees were not good for much
of anything. The BT-13’s did, however, have a 450 hp P & W and
prop up front that were worth the entire price of the airplane (generally
about $400). The conclusion was obvious, so ag-operators snatched many
of the old BT’s up, the engines were yanked off and the carcasses
pushed off to the side and ignored. For years, cannibalized BT-13’s
littered grassroots airports nationwide.
The airshow guys were right on the heels of the dusters but they went
the ag-operators one better: they wanted to improve the airplane’s
roll performance as well as its ability to climb, so an extra set of ailerons
were installed on the top wings and slaved to the bottom ones. Now, the
old airplane could not only leap off the ground and had a modicum of vertical
performance, but it could actually roll with the best of them. Sort of,
The stodgy old school teacher had been turned into a rock ‘n rollin’
From a pilot’s point of view, you have to have flown a stock Stearman
to appreciate the dramatic improvements airshow types have made to the
airplane. Flying aerobatics in a stock Stearman is a continuous, irritating
cycle—nose down, down, down, wait, wait, now pull. Do one maneuver,
then climb, climb climb to replace the altitude lost.
Where an original 220 hp Stearman spends a lot more time diving to gain
energy and then climbing for altitude than it does doing aerobatics, the
450 hp bird has almost all the energy it needs bolted to its nose. It
needs only a gentle nod down before it’s ready to be pulled up into
whatever maneuver the pilot desires. So, when you see John Mohr doing
his airshow routine in a 220 hp Stearman, you are seeing one of the very
best aerobatic pilots in the world, because his airplane isn’t doing
a single thing to help him.
The extra ailerons do wonders for the airplane in rolls. Not only are
the forces lighter (a stock Stearman is a “manly” airplane),
but the roll rate is such that, although it’s not a Pitts or Extra,
it lets the acrobat do point rolls or anything else around the longitudinal
axis with no danger of separating a rotator cup.
The Super Stearman is known as “super” for a reason. Otherwise,
it’s just another Stearman and the grin factor isn’t nearly
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