Propeller Storage & Preservation, Module 17, Certify66

Notes

Main ideas

Corrosion is the chief threat to a stored propeller (and internal corrosion to the hub/pitch-change mechanism), so preservation centres on keeping moisture out and inhibiting exposed metal.
Preservation includes applying corrosion-preventive compounds, fitting blade and hub covers/blanks, and sealing openings; the pitch-change mechanism and bearings are protected against moisture ingress.
The propeller is stored in the manufacturer's specified position, often with the blades horizontal, to prevent oil draining to one side, flat spots on bearings, or fluid pooling.
WOODEN propellers need particular care: stored to avoid warping and moisture absorption (typically hung or laid flat per the manual, in a stable humidity), because uneven moisture distorts the blade and unbalances it.
A stored propeller is DE-PRESERVED before fitting, covers and inhibitors removed, condition and balance re-checked, before return to service.
⚠ Exam trap: corrosion is the main enemy of a stored propeller; follow the manufacturer's storage POSITION (e.g. blades horizontal) to avoid oil draining and flat spots, and store wooden props to prevent warping/moisture, then de-preserve before use.

Solved examples

Why must a wooden propeller be stored in a controlled way, and what happens if it is not?
Wood absorbs and releases moisture unevenly with humidity. If stored badly, leaning, in damp, or with one face exposed, the blade takes up moisture unevenly, warps and changes shape. That distorts the aerofoil and, critically, unbalances the propeller, causing vibration. It is stored per the manufacturer's instructions (position and humidity) to keep it straight and balanced.

Propeller Storage & Preservation