Spitfire IIa prop pitch

[TomcatViP]

Originally Posted by Crumpp

NO...You have confused automatic devices.

The VDM hydraulic electric propellers are CSP in hydraulic mode and variable pitch in electric mode.

Schwarz-man, whom I know and he is correct in his explanation of how the SYSTEM works.

He is describing the interaction of the CSP PROPELLER with MANIFOLD PRESSURE of the ENGINE!!

This eliminated the pilot from having to adjust PROPELLER RPM as with ANY CSP and then have to adjust ENGINE MANIFOLD PRESSURE. It reduced his workload when compared to a using a CSP on regular aircraft engine with manual controls.

+1

I hve eard of that also since long.

Two set of pitch ctrl mechanisms from early design : hydro and elec (that's why the pitch adjust itself slower when eng is off).

The manual pitch crtl was selected only at T.O and landing (11h45 and 11h30 are the value standing in my memory)

The system auto adjust the best pitch value in fonction of eng boost, speed (my guess - not sure ) and barometric alt leading to a given rpm.

It's a primitive version of the system found in the 190 but seemingly working fine as it was installed even on latte war versions.

That wld be interesting to dig into that .

Regarding the Merlin CSP, it was a demanding arrangement. You can found trace of this in the Merlin's mustang evaluation report that clearly say that despite increased workload for the pilot the new perfs achievable was a fair price to pay.