Black 6 Thu 19th Apr update re Spit II

[41Sqn_Banks]

Originally Posted by camber

Excellent! Two references which really clarify the Spit II boost operation:



This is a great explanation of the "take off boost" gate. Because the gate represents not an automatically controlled boost level, but an ability to reach a given throttle valve opening without boost control, this override throttle valve opening % must be calibrated for a typical atmospheric pressure at sea level (to give +12.5). So the boost level of +12.5 psi is approximate, under sea level it would get higher

My interpretation is that it is calibrated to +12 but on some days would rise to +12.5 and on other only to +11. So there is a 0.5 safety mentioned in the manual so the pilot doesn't panic if boost is higher than +12 on one day.

Lane:

Those are very useful combat reports. Even though it contradicts my idea that the +12psi was delivered through main throttle operation Clearly the Spit II red tab IS used in combat, logically it was to deliver +12psi as per Banks post (although this is not stated explicitly).

Although the gate can only give any benefit at low level, the second report re-inforces my idea that pilots might use it "just in case" at any level. In this case the pilot pulled his boost tab, gated the throttle at maximum rpm, and felt re-assured that he was getting maximum performance!

We should have a closer took to the mechanic of the boost control to understand what happens if gate and cut-out are activate at the same time. I'd suspect that the gate has the upper hand.