for the prop
A combination of nitrogen or air pressure, a spring, blade counterweights and governor-regulated oil pressure is utilized to change the pitch of the propeller blades.
The nitrogen charge, spring, and counterweights are all acting to "feather" the propeller while your governor forces pressurized oil into the prop hub assembly to decrease blade angle and increase engine/prop RPM.
ex.
As the propeller lever is pushed forward, increasing the propeller RPM, a valve in the governor allows increased oil pressure to enter the propeller hub and move the blades to the low pitch (increased RPM) position.
Basically the oil pressure from the governor is counteracting the spring/nitrogen & counterweights.
for the gear
If my memory serves correct, the gear system on the Seminole is the same as the Piper Arrow. Anytime the gear is in transit, you will have a red gear unsafe light. You can verify the hydraulic pump's operation by sight, sound, and feel. You can see/feel the plane pitch when the gear is in transit and also hear it sometime. Also watch the ammeter gague when you raise or lower the gear. Should see a significant jump in amerage being put through the system. The unsafe light will also sound when the gear is not down and locked with the selector in the down position (really?) and when you have the flaps in the approach position without the gear down. Might be some others but I cant remember for the seminole. MP below ___ inches of Hg....?
best of luck
au
A combination of nitrogen or air pressure, a spring, blade counterweights and governor-regulated oil pressure is utilized to change the pitch of the propeller blades.
The nitrogen charge, spring, and counterweights are all acting to "feather" the propeller while your governor forces pressurized oil into the prop hub assembly to decrease blade angle and increase engine/prop RPM.
ex.
As the propeller lever is pushed forward, increasing the propeller RPM, a valve in the governor allows increased oil pressure to enter the propeller hub and move the blades to the low pitch (increased RPM) position.
Basically the oil pressure from the governor is counteracting the spring/nitrogen & counterweights.
for the gear
If my memory serves correct, the gear system on the Seminole is the same as the Piper Arrow. Anytime the gear is in transit, you will have a red gear unsafe light. You can verify the hydraulic pump's operation by sight, sound, and feel. You can see/feel the plane pitch when the gear is in transit and also hear it sometime. Also watch the ammeter gague when you raise or lower the gear. Should see a significant jump in amerage being put through the system. The unsafe light will also sound when the gear is not down and locked with the selector in the down position (really?) and when you have the flaps in the approach position without the gear down. Might be some others but I cant remember for the seminole. MP below ___ inches of Hg....?
best of luck
au