PPRuNe Forums - View Single Post - Boost (Hurricane 1 and Merlin II/III)
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Old 17th Feb 2012, 09:43
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Genghis the Engineer
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So in a nutshell - Boost, normally expressed in in.Hg, is MAP minus (MAP at a nominal cruise power setting). So idle is something like -8 Boost, and combat power was around +10 boost, expressed in in.Hg.

It was used, as MAP is, for setting power in general preference to using RPM. The Hurricane 1 did not have a constant speed prop - the earliest models had a fixed pitch prop, the later models had a variable-fixed pitch prop with a choice of two or three pitch settings. So a pitch setting was made, then the powerplant was controlled on the throttle, primarily by reference to boost pressure, rather than RPM.

Have I got that right?

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