I'm not an expert, and don't play one on TV, but here goes with some stuff I
remember about aquaplaning from 42 years experience as a pilot. (R.A.F.,
testing for Short Bros, BEA, and American Airlines for 27 years).
Back in about '54, USAF did extensive trials on F86 (Sabres), T33 (T-Birds)
and F84 (Thunderbirds?). The RAF did the same on Canberras (later the B57).
They created various standing water situations on concrete and tarmacadam
surfaces with armored glass inserts with cameras mounted underneath. The main
features I remember about the report are as follows:
1. Tread pattern had little or limited effect. Smooth tires reacted pretty
much the same as treaded ones. (Golf ball spin tests produced similar
results, until square grooves came along.)
2. Vehicle/aircraft weight also made little difference.
3. A constant, however, emerged. In nearly all circumstances, aquaplaning
occurred at approximately nine times the square root of the tire pressure.
Airliners maintain main wheel pressures of about 150 psi, and nose wheels at
about 100 psi, producing AP speeds of about 110 nmph 100 nmph. This
corresponds pretty closely to typical touchdown speeds at low landing
weights.
Auto tires at 25 psi would result in AP speeds of 45 nmph, (52 mph), and 36
psi pressures would give an AP speed of 54 nmph, (62 mph). Of course, such
high pressures would be disadvantageous in other respects!
Sorry if I bored everyone to death. It just proves "a little knowledge is a
dangerous thing", and retired folks have too much spare time.
Mike Noad
CC75088L Post-restoration road test tomorrow. Wish me luck.
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