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| One of the most
satisfying maneouvres, the Hammerhead needs tons
of practice and involves climbing at exactly 90
degrees, then yawing to the left or right and
turning the aircraft as though the inner wing was
the pivot point. The knack is to change from 90
degrees up to 90 degrees down within a
wing’s length. It is the most elegant
maneouvre and deeply rewarding when you know
it’s right. The key (in Fly II) is to
GRADUALLY introduce the rudder at the top of the
climb, and WELL before the speed decays. Start
with similar airspeed to the loop, then climb
exactly perpendicular to the ground, keeping dead
straight all the way up. |
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| Just before
airspeed decays less than 60 knots, and with
plenty of power on to assist airflow over the
rudder, we apply GRADUAL (in this case) right
rudder. You may need a little opposite aileron to
counteract roll, even at this slow speed. If the
aircraft is not exactly pointing straight up, you
will probably either collapse the move into a
sort of back flip, or the nose will drop
forwards. The key is to know when to apply that
rudder. In this example, luckily I was pretty
straight all the way up and I was rewarded with a
nice pivoting “hammerhead” turn to the
right. You need plenty of power to keep
sufficient airflow over the rudder. Once the turn
has established and the maneouvre assured, reduce
power. |
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| Once we reach this
point there is little we can do except wait, for
there is no dynamic flow sufficient for us to
intervene until the nose has dropped down. It’s
pretty satisfying to know that the preparation up
to this point was good. By the way I recommend
practicing these tricks in spot view as well as
from the cockpit. (the best one is the THIRD spot
view which fixes the view point and gives the
best idea of aircraft movement). You can also use
the instant replay in Fly II to see where you
went wrong. The advantage is that you can replay
several times over all with different views from
inside and outside the cockpit.
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| The recovery - not
perfect in this case as the nose has wandered up
a little from 90 degrees, but then as you see
I’m doing this a little too near the ground
for comfort. As the Citabria
flips itself from parallel to perpendicular you
will notice a tendency to oscillate in yaw whilst
the nose and tail adjust to the airflow - you can
damp this out with rudder opposite to the
direction of yaw.
As
with the loop, ease out of the dive with idle
thrust then establish cruise thrust and level
attitude. By the way,the Hammerhead is often
erroneously called the “stall turn”. In
fact throughout this maneouvre the aircraft never
stalls because the wing angle of attack is never
high enough.
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