PAGE THREE
Lined up and ready to go, I wrapped one hand around the base of the
throttle lever and moved it smoothly up towards the stop. With 260
horses on tap, the little Italian is more than eager to reward you
with really excellent acceleration. Interestingly enough, it was slightly
less than I was used to in an A model. We racked the airspeed indicator
up to 60 knots almost immediately and a gentle tug on the stick got
the nosewheel off the ground, running on the mains for a short distance
until we reached a speed that made that highly tapered wing happy.
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SF260 gear is sensitive to
rigging and a lot of them have wound up on their noses |
Off the ground, I made a mental note to pull out on the gear handle
before bringing it up. It's easy to tug at the handle, thinking you
have retracted the gear but still have three lights glaring at you.
This is one of the better gear retraction systems I have worked with
because you really have to work to accidentally get the wrong lever
on landing. Takeoff flaps are 15 degrees and once you have airspeed
over 90 knots (which is almost as soon as your gear is up) you can
bring them in with no fear of settling.
Although best rate of climb is somewhere between 90 and 100 knots,
I found it much more comfortable to climb out at 110 knots indicated
because it gave a much flatter nose attitude and better visibility.
Even so, we were going upstairs at well over 1,000 feet per minute.
At max rate of climb, it's not unusual to see climb rates from 1,500
to 1,700 feet per minute.
ONE OF THE FIRST THINGS I NOTICED WHEN taking off in the turboprop
the weeks before was the lightness and quickness of the ailerons, so
I was prepared when flying Sterbutzel's airplane. The original A models
had quick response but fairly stiff ailerons; not enough to be objectionable,
but enough so the breakout forces kept you from doing much meandering
away from dead level flight. The story being circulated in SF.260 circles
is that some air force wanted to fly the SF.260 with hard hats which
required them to lower the seats by several inches. This put the stick
up at nose level so they shortened the stick a corresponding amount
which reduced the mechanical advantage making the ailerons unacceptably
heavy, so the factory designed a set of servo-tabs to lighten the forces.
Whether the story is true or not, the bottom line is the 260 C has
quite light breakout forces and still has the excellent response of
the A model, making for a truly joyous combination. In fact, the combination
is so nice it was all I could do to wait until I reached legal altitude
and airspace before I started rolling left and right.
As with the jet aircraft the 260 is supposed to emulate, the adverse
yaw is absolutely zero. In fact, you can jerk the nose up to 20 degrees
and put your feet flat up on the floor while jamming the aileron
into the corner to produce a perfect aileron roll. I found you could
roll from virtually any speed and the extremely clean
airframe would let the nose up to indecent angles when doing huge
barrel rolls right and left, bleeding one into the other like giant
figure eights.
I had no idea what the proper entry speeds were for loops, but dropping
the nose slightly to get 170 knots indicated seemed to produce a loop
that was a might bit slow on the top although the 260 gave no indication
of unloading on me and half-snapping around right side up. As long
as I didn't put on G when slow, the plane seemed to know exactly where
it was going.
Shepard had crawled alongside of us by this time in his A model, and
we thought we'd see what the C model had given away with a new wing
design. We found that almost regardless of the speed, Shepard would
indicate a full 2 to 21/2 inches less in manifold pressure. The C model
would indicate 160 knots at 23 inches and 2,400 rpm and Shepard was
loping along at a mere 201/2 inches. John Stirling had brought one
of the airplanes across the Atlantic with Mike Moore and he agreed
with Moore that you could flight plan the C models at 165 knots and
be fairly sure of getting it. Shepard, on the other hand, said he'd
flight plan at least 10 knots faster than that.
What did the 260 gain in modifying the wing? The only way to find
that out was to bring the power back and haul the nose up to see how
the airplane performed at the low end of the speed spectrum. Letting
the speed come down to around 75 knots, I continued holding the nose
up until I could feel a sizeable buffet building up. I continued bringing
the stick back and, at some number in the vicinity of 60 knots, the
stick hit the stop and the airplane dropped its nose and rolled gently
off to the left. I tried that several times and then Stirling said, "Let
me show you something." Taking the airplane, he flew straight
ahead into a stall and as the aircraft stalled, he pulled the stick
to the stop and kept it there, keeping the wings level by ailerons
with no difficulty whatsoever. This was an entirely different airplane
from the A model in that regime. In the same situation, the A model
has no ailerons. In fact, a knot or two before the A model stalls,
you can't assume you'll have enough aileron for you to pick up a wing
should it drop. Also, the stall in the A model is much less predictable
and more likely to bite you. I took the C model into accelerated stalls
in turns while sliding the ball inside and outside and the aircraft
performed exactly as you would expect from any other airplane. Although
slower at the top end, the 260 C definitely has much better manners
than its predecessors, something which makes a much better
primary trainer and certainly brings the C closer to being an everyman's
airplane.
The question of which is better, the blood and guts "A" model
or the more refined "C," is a matter of taste and mission.
There's a very slightly different feel on the C model, an indescribable
one, that would possibly only be noticeable to one who has flown the
airplane a few hours: the A model somehow seems a little more solid
and more sure of itself, however, that may be purely a perceptive difference
brought about by the tighter ailerons. The C model definitely has the
A beat all to pieces in the roll department, and of course its low
speed characteristics are so much different it might as well be a different
design.
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