EN-1320
OPERATION AND INSTALLATION MANUAL
4.2.1. For Pratt
&
Whitney Application
Outside the hub there are check nuts and in the inner part of the hub there are 3 stop nuts.
High pitch/feathering can be set by turning the check nuts. Low pitch can be set by turning the
internal stop nuts The full reverse stop is not adjustable in the field.
4.2.2. For Garrett Application
Outside the hub are two check nuts. High pitch feathering stop can be adjusted by turning the
check nuts. The beta tube is installed in the guide rod. Due to turning the beta tube inside or
outside, the hydraulically low pitch stop can be adjusted.
The beta tube is secured by the screw AN3H-13A and the stop nut MS 20364-1032A.
Put on both sides washers AN 960-10.
4.2.3. For Walter Application
All stops are internal and can not be changed. No adjustment is necessary, because during
manufacturing all pitch settings were made.
4.3.
Propeller Blades
Propeller blades are made from aluminium alloy. They are turning in the ball bearings with one
set of balls in the propeller hub. Connection with the pitch change mechanism is made
through
plastic pitch change blocks installed on the pins in the blade shank (threadless-type blades) or
on the blade bushing face (thread-type blades).
Propeller blades can be designed with counterweights installed on the blade shank.
Leading edges of the blades can be protected with polyurethane guards for mechanical
damages prevention.
4.4. Counterweights
Propellers may by equipped with counterweights on the blade shanks or as the part of the hub.
If governor supplied oil is lost during operation, force from counterweights move the blades to
high pitch and feather to prevent propeller overspeed.
4.5. Spinner
The spinnerdome is made from fiber reinforced composite or spinformed aluminum alloy. The
bulkhead is spinformed or truncated aluminium alloy.
If the spinner dome has no integrated stiffeners, then the front support is installed as part of the
hub. Filler plates increase the stiffness of the dome on the cutouts for the blades. The dome is
mounted on the supports by means of screws.
61-10-20
DESIGN AND OPERATION INFORMATION
Page 4-2
2017-10-06
