What happens to the angle of attack when there is less oil pressure in the prop system?

When there is less oil pressure in the propeller system, it affects the pitch of the propeller blades. In most constant-speed propeller systems, lower oil pressure can lead to the blades moving to a higher-pitch setting due to the design of the propeller control mechanism. This higher pitch creates more resistance against the airflow, effectively reducing the RPM of the propeller.

As the propeller blades pitch up, the angle of attack of the blades increases. Additionally, since the aircraft's airspeed may not change immediately, the overall lift produced must be managed through adjustments in the angle of attack of the wings. The pilot may have to compensate for this by increasing the aircraft’s angle of attack through pitch adjustments, which can lead to a further increase in the angle of attack of the wings as they try to maintain lift and control.

Therefore, when oil pressure decreases in the prop system, the result is an increase in angle of attack as the propeller blades pitch up and the overall aerodynamic configuration of the aircraft is affected.