Propeller Owner's Manual
136
TESTING AND TROUBLESHOOTING
61-00-36
Page 4-12
Rev. 2 Feb/17
G. Beta Range Operation
(1) Propeller refuses to enter beta range from low pitch
blade angle.
(a) Propeller RPM is not below 900 RPM.
1
Beta lockout flyweights in the beta lockout
assembly prevent movement into the beta range
unless the engine/propeller speed is below
900 RPM.
2
Beta lockout flyweights will not disengage from
a groove in the barrel (inside diameter) because
of damage. Propeller must disassembled and
repaired by qualified personnel at a certified
propeller repair station with the appropriate
rating.
(b) Low oil pressure. Oil pressure supplied to the
propeller by the pressure control unit when
commanded by the pilot control is less that required
to move blade angle from low pitch into beta range.
1 Check the output oil pressure increase on the
oil pressure gauge that is connected to the
pressure control unit. Refer to Figure 2-2.
2 Oil pressure increase from the Position 3 oil
pressure valve at low pitch (refer to Figure 3-16)
should be a minimum of 75 PSI to easily enter
beta range.
3 Pressure relief compression spring in the
pressure control unit may be broken. Refer to
Figure 2-2.
4 Relief valve may be jammed or broken. Refer
to Figure 2-2.
(c) Mechanical connection between the pilot control
to the pressure control unit is either jammed or
disconnected.
