Technical data

13773-001
61-10
Page 1
PROPELLER ASSEMBLY
1. DESCRIPTION
The propeller assembly consists of a hollow aluminum hub which supports the propeller blades and also
houses the pitch changing mechanism. Movement of propeller blades is controlled by a hydraulic piston/
cylinder combination mounted on the front of the hub. The linear motion of the hydraulic piston is transmit-
ted to each blade through a pitch change rod and fork. A pitch change knob at the base of each blade
intersects with the fork.
Blade pitch is controlled by the governor. The governor supplies oil to the propeller hub to move the blades
toward high pitch position (decreased RPM). Conversely, the propeller blades move toward low pitch posi-
tion (increase RPM) as the governor drains oil away from the propeller hub. A mechanical spring is
installed within the propeller to assist movement of the blades to a lower pitch position as RPM decays
since blade centrifugal twisting moment is only present when the propeller is rotating. The mechanical
spring will insure that blade angel will reach the low pitch stop when the propeller is static. If oil pressure is
lost at any time, the propeller will move to low pitch.
The propeller assembly employes high-strength, aluminum blades. It is essential that the propeller assem-
bly be maintained in accordance with Hartzell Propeller recommended service procedures. These proce-
dures are detailed in the Propeller Owner’s Manual and Log Book listed in the list of publications at the
front of this manual. (List of Publications)
2. MAINTENANCE PRACTICES
A. Propeller (See Figure 61-101)
WARNING:
Ensure magneto is grounded (OFF) and ignition key is removed prior to perform-
ing maintenance.
(1) Removal - Propeller
(a) Acquire necessary tools, equipment, and supplies.
(b) Ensure master and magneto switches are off, and ignition key is removed.
(c) Move fuel selector to OFF position.
(d) Place mixture control in idle cut-off.
(e) Remove engine cowling. (Refer to 71-10)
(f) Remove screws and washer securing spinner dome to spinner bulkhead and remove
spinner.
(g) Position hoist and lifting sling forward of airplane and attach sling to propeller.
(h) Place a drain pan beneath propeller to catch oil spillage.
(i) Loosen and remove nuts and washers attaching propeller to engine flange.
(j) Remove propeller from airplane.
Description P/N or Spec. Supplier Purpose
Hoist - Any Source Hoist propeller.
Sling - Any Source Secure propeller to
hoist.
Drain Pan - Any Source Receive waste oil.
30 Nov 2000