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Old December 17th 06, 02:08 PM posted to rec.aviation.military.naval
John Carrier
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Posts: 85
Default Landing speeds for naval aircraft?


"Dudley Henriques" wrote in message
...

"Frank Minich" wrote in message
...
Sorry to jump in late.


I always understood the AOA units were somehow calibrated but arbitrary,
so the 139 KIAS was the nominal speed that corresponded to on-speed AOA
with full flaps and 50,000 pounds max-trap weight.


Units should be either a percentage of the lift coefficient curve for the
wing or a percentage of the AOA vane as determined by the OBC depending on
the type if I remember....but I'm getting old :-)).

Dudley Henriques


An often arbitrary measurement of fuselage angle of attack. Sometimes
actual degrees based on the aircraft's ADL/WL (F-18), Sometimes
approximating degrees, sometimes not. The system used either a vane which
fared into the wind or a cylinder or cone with two slots machined into it
(it would rotate into the free stream to equalize the pressure in the two
slots). The angle of rotation is detected by a transducer which sends the
signal to the AOA indicator(s). Usually the front cockpit indicator drives
the cockpit indexers, approach lights (for the LSO) and any stall warning
associated with AOA.

The T-45 AOA formula is Indicated AOA = (Actual AOA + 8.93) / 1.025. No
****. I teach this stuff. One unit AOA deviation from optimum approach AOA
(17 units and approx 8.5 degrees) is 3 knots. A very precise way of
monitoring airspeed and attitude for a carrier landing.

R / John