COMBAT AND COMPETITION.pdf - Lakes Gliding Club

CHAPTER ELEVEN A TESTING TIME
of petrol rationing. When the time came all was well. The weather gave
us seven good days and a hard fought contest between Tony D2 who
eventually won, Nick Goodhart who was second, his brother in the 403
and myself third and fourth respectively.
Soon afterwards the 403 returned to Twinwood, where its
manoeuvrability and the big fin and rudder assembly really came into
their own, as I worked up a routine for the National Acrobatic Contest
at Dunstable. But slow rolls required considerable care and plenty of
practice. Even an experienced acrobatic pilot needed his wits about
him.
So it was with something akin to horror that I watched Harry
Midwood release from a high aerotow one morning and observed, from
the nature of his subsequent manoeuvres, that he was attempting to
teach himself how to slow roll!
We had talked it through enough, and he certainly knew the
theory, but at the very least he would have been wise to opt for a dual
session on the Tiger Moth, before trying his luck on the 403. However
Harry is a determined chap and his careful, step by step, approach got
him there in the end with relatively little drama.
At Dunstable, where Sandy Powell chief test flying instructor from
my ETPS days was secretary to the Lockheed acrobatic judges, they
seemed to approve of slow rolls and inverted flying. Although
penalised for failing to include a spin I came second to Dan Smith
whose immaculate display in a standard Olympia brought him a well
deserved win.
Back at Twinwood once more - where we were working on the 403
to reduce the stick free stability and the stick force per 'G 1 - the
pressure was on again. The stalling speed was higher than the 402,
there was a suspicion of a premature airflow breakaway over the wing
root at high angles of attack, and Tony Goodhart had been unhappy
with the low speed performance.
Harry ran some tests and soon established that the thicker wing
root (20% compared with the 402's 18%) - introduced for structural
reasons - was the main culprit. Reverting to an 18% root section was
the first step - and reducing the tailplane mass balance as much as
possible, in favour of a bobweight well forward in the elevator circuit,
would mean a substantial saving in ballast. Sufficient in total to make
good the 403's performance shortfall at low speed.
However by the time we had flown a fully modified tailplane
Horace had the bit properly between his teeth. He wanted more
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