Is it permissible to cold straighten a damaged aluminum alloy propeller blade to facilitate shipping it to a repair station?

• A. Yes, if it is minor damage.
• B. No, this could cause hidden damage that may render the blade nonrepairable.
• C. Yes, this is standard shipping practice.
• D. Only with manufacturer approval.

Answer: (B)

Cold straighten a damaged aluminum propeller blade is not allowed. Aluminum blades can harbor hidden flaws such as microcracks or subsurface fatigue that aren’t visible on the surface. Forcing a bend or hammering to “straighten” the blade introduces work hardening and residual stresses, which can mask or propagate cracks and potentially render the blade unrepairable. The proper course is to leave the blade in its damaged condition and send it to an approved repair facility where non-destructive testing and manufacturer-approved repair procedures can determine the extent of damage and the appropriate repair or replacement. That’s why this is not permissible to facilitate shipping.