Its important to highlight again that,
CAPFlyer, you stated,Scott - A2A wrote:The engines in the Connie (and 377) us the Microsoft built-in tech..
Starting with the second statement, the L-049 does not have electric propellers. The A2A manual mentions "Hamilton Standard 3-blade 'Hydromatic' adjustable/constant-speed, full feathering (later reversible)" propellers (p.53). Going beyond this, the FAA TCDS gives two options for propellers... both with the same Hamilton Standard Hydromatic 33E60 Hub.CAPFlyer wrote:on electrically actuated props the prop pitch MAY change when actuated while on the ground and the engine stopped. This is because some electric props directly pump fluid in/out of the prop dome and governor instead of moving the governor control only. The prop on the L-049 and B-29 are this type.
The first issue is that these propellers require oil pressure to move the blades. The first method of obtaining this pressure is the engine driven mechanical oil pump, which requires engine rotation to function. The next method is via the electrically powered feathering pump, but operation of this pump is via the feathering buttons (not the propeller RPM switches) and it bypasses the governor entirely. The engine isn't turning, so we know the mechanical pump is out, which means only the feathering pump is available. With my testing, the blade pitch only changes with the batteries connected, so we must be using the feathering pump. If I was indeed using this pump, then upon activation it would continue to provide pressure until the blade pitch either reached the feathering stop, or the full fine limit. As it currently functions, moving the RPM switch to 'increase' reduces the pitch of the stationary blades. When the switch is immediately released, the change in blade pitch ceases. This behavior is the same for 'decrease' and increasing blade pitch. This suggests that the governor is controlling the feathering pump (or this is default MS engine coding with an RPM switch instead of lever )
The next problem is the workings of a constant speed governor. Governors work by controlling the propeller pitch to change the induced drag acting against the torque of the engine to correct deviations from selected RPM. They do this by detecting either an "Underspeed" or "Overspeed" condition and correcting the error until the RPM returns to an "Onspeed" condition. With the engine stopped, any RPM selection other than 'Feather' will result in the governor detecting and underspeed situation, and the response will always be to drive the propeller blades to fully fine pitch. This is regardless of the selected RPM because all RPM>0.
This excludes Feather operation, but again feather operation excludes the governor anyways.
From some quick research on Curtiss Electric propellers, it does seem that they can be placed into a manual mode where the prop pitch can be changed by the crew, without governor control. So, I fired up my United colors A2A B-377 (The one that I know has Curtiss props). Surprisingly, it has improved governor operation over the Constellation. With an engine stopped, RPM lever (and switch) commands result in no change in visible blade pitch. The blade pitch always stays in full fine, because the governor is always Underspeed.
The only exception is through use of the overhead feather switch, which immediately drives the stationary propeller to Feather. Turning off this switch does the exact opposite.
My next test will be to to try and feather the stationary Hydromatic Constellation propeller with the Feather button. I think that should work, assuming the feathering pump is electric.
This is all purely conversation, now that we know what's going on with the simulation (perhaps I should have moved this out of tech support? Oops)