Clipped-Wing (32' 6" span) versus Standard Version (36' 10" span)
Air Fighting Development Unit at Duxford
The following information comes from flight trial held late in 1942.
Method of test
Two Spitfire VB aircraft were selected with a performance which was
almost identical, the loading and equipment carried were standard
in each, and the propeller, engine and finish of each aircraft were
similar. A test flight was made under maximum cruising conditions
and no differences could be determined. The Wing tips were then
removed from one aircraft and trials were carried out , each trial being
performed twice to enable the pilots to be changed. The wing tips
were then replaced on one aircraft and removed on the other and
similar tests carried out. Differences in speed were taken as relative
increases or decreases owing to possible instrument inaccuracies,
and position error differences with and without tips. Readings for
level speeds were taken at 10,000, 15,000, 20,000 and 25,000 ft;
zoom climbs were made 10,000-15,000 ft. and 20,000-25,000 ft;
dives were made with similar engine settings.
Results of Comparative Tests
10,000 ft. In each case the clipped wing Spitfire proved the faster by
a small margin about 5 mph.
15,000 and 20,000 ft. The average results at these two heights showed
that the difference in speed is not measurable.
25,000 ft. The standard (wing) Spitfire is very slightly faster than the clipped
In all level speed runs the clipped wing Spitfire accelerated faster than
the standard wing Spitfire.
The average difference in time during zoom climbs from 20,000 to
25,000 ft. was 15 seconds in favor of the standard wing Spitfire.
From 10,000 ft. to 15,000 ft. no differences were indicated.
In all diving tests the clipped wing Spitfire drew away from the standard
At all heights to 25,000 ft. the rate of roll is considered improved by the
removal of the wing tips. The response to aileron movements is very
quick and very crisp. Four dog-fights were carried out, starting with
the standard Spitfire on the tail of the clipped wing Spitfire. On two
occasions the clipped wing Spitfire evaded so rapidly in the rolling
plane that it was able to lose the standard Spitfire and reverse the
positions in about 20 seconds. On the third occasion the clipped
wing Spitfire was also able to lose the standard Spitfire. The fourth
occasion was at 25,000 ft. and the standard Spitfire was able to keep
the clipped wing Spitfire in sight.
The minimum turning circle of the clipped wing Spitfire at 20,000 ft.
has been increased by 55 ft. at 1,025 ft. compared with the Fw 190
turning circle of 1,450 ft. (RAE Farnborough figures). This slight
increase does not therefore detract from the fighting qualities of
the aeroplane in any way, since the clipped wing version is unlikely
to be in combat with the standard Spitfire.
No difference was detected.
No difference detected.
The view downwards over the wing tips is improved considerably.
The strengthening of the wing by removal of the wing tips may permit
higher maximum IAS to be used.
Edited by CORSNING, 24 July 2017 - 07:21 PM.