(Corey C. Jordan) wrote:

On Tue, 19 Aug 2003 23:09:39 GMT, (Corey
C. Jordan) wrote:

After 20 minutes
of this, at 1,000 ft. altitude, the Spit tried a Spit-S (at a 30-degree
angle, not vertically down). Lowell stayed with the Spit through the
maneuver, although his P-38 almost hit the ground.

After posting this I was a bit troubled by the statement that a Spitfire Mk.XII
attempted a split-S from 1,000 ft. AGL.

So, I jumped into Hitech Creation's WWII combat sim and tried the maneuver
in a Spitfire Mk.Vc, Spitfire Mk.IX, Spitfire Mk.XIV and a P-38L.

As far as I'm concerned, it's improbable at best. Here's the minimum altitude
required to safely execute a split-S in each type beginning at 250 mph TAS,
throttle pulled back to idle.

Spitfire Mk.Vc: 1,300 ft
Spitfire Mk.IX: 1,450 ft
Spitfire Mk.XIV: 1,600 ft
P-38L-1-LO: 1,700 ft.

Note in your original post and again in the lead to this elaboration
the parenthetical notice that the maneuver was "at a 30-degree angle,
not vertically down."

Just as the description of what Lowell was doing isn't technically a
"Cloverleaf", so also this is not a "split-S." It's a descending hard
turn, almost what is referred to in more modern terminology as a
"sliceback". Whenever you use some descending vertical in a turn, you
decrease your turn radius gaining some radial G from gravity.

To return to the original description of Lowell's maneuver, it sounds
as though he was exercising a series of high and low yo-yos. First, to
control overtake and reduce angles, he pulls the nose up to slow and
minimize overshoot of the target's turning circle. Then from high
slightly outside the target flight path in a lag pursuit position, he
rolls over and lowers the nose to take a cut across the target's
circle and gain closer. A high yo-yo, followed by a low yo-yo.


Ed Rasimus
Fighter Pilot (ret)
***"When Thunder Rolled:
*** An F-105 Pilot Over N. Vietnam"
*** from Smithsonian Books
ISBN: 1588341038