AD-47-11-02
Hartzell Propeller

Category: navion, propeller

Applicability: All models equipped with Hartzell HC12x2O-1 propeller hubs and 8628 blades.

Supersedes: Was mandatory note 2 of AD-782-3.

Compliance: To be accomplished not later than May 1, 1947.

Procedure:Vibration tests of the Hartzell HC12x2O-1 propeller with these airplanes indicate that the propeller diameter should be reduced from 86 inches to 84 inches. This is accomplished by cutting 1 inch from the tip of each 8628 blade, and making the shortened blade 18428R. This blade rework must be performed either by the Hartzell factory or by a certified propeller repair agency.

Upon compliance with this AD, the presently required placard against engine operation between 1,950 and 2,150 r.p.m. and over 2,250 r.p.m. may be removed.

Paragraph B of North American Field Service Bulletin No. 20 dated January 28, 1947, covers this rework.


AD-47-11-02