OPERATION AND INSTALLATION MANUAL
EN-1320
7.0. MAINTENANCE
7.1.
There are no frequent maintenance works required on the hub because all moving parts are
inside the hub and not exposed to the environment. Blade bearings and pitch change
mechanism are filled with special lubricants and there is no need to refill between overhauls. A
corrosion protection of the hub with thinned engine oil or anticorrosion spray is recommended.
7.2.
Repair of spinner parts is not permissible. Cracked spinner domes, filler plates and backplates
are to be replaced by airworthy parts.
7.3.
In case of a ground strike with Aluminum blades, refer to Blades Overhaul Manual for
evaluation.
7.4. DYNAMIC BALANCE
NOTE:
All manufactured or overhauled propellers are statically balanced. Dynamic balance is
recommended but not required unless specified by airframe or engine manufacturer.
7.4.1. Overview
7.4.1.1.
Dynamic balance is accomplished by using an accurate means of measuring the amount and
location of the dynamic imbalance. After such a undertake the remaining imbalance should
be below 0,2 ips.
7.4.1.2.
Follow the instructions from the equipment manufacturers for dynamic balance.
7.4.1.3.
If the dynamic imbalance is bigger than 1,2 ips, the propeller must be removed and statically
rebalanced.
7.4.2. INSPECTION PROCEDURES PRIOR TO BALANCING
7.4.2.1.
Visually inspect the propeller assembly after it has been reinstalled on the aircraft prior to
dynamic balancing.
NOTE:
The First run-up of a new or overhauled propeller assembly may leave grease on the blades
and inner surface of the spinner dome. This is normal and do not mean that it will be a
continuing grease leakage.
Use a mild solvent to completely remove any grease on the blades or inner surface of the
spinner dome.
7.4.2.2.
Prior to dynamic balance record the number and location of all balance weights from the static
balance.
7.4.2.3.
It is recommended that placement of balance weights on aluminum spinner bulkheads which
have not been previously drilled be placed in a radial location.
7.4.2.4.
The radial location should be outboard of the slip ring and inboard of the bend at which point
the bulkhead creates a flange to attach the spinner dome.
61-10-20
MAINTENANCE
Page 7-1
2017-10-06
