AD 76-14-09

76-14-09 CURTISS-WRIGHT: Amendment 39-2672. Applies to C632S type propeller equipped with 744-6C2-() series hollow steel blades installed on but not limited to Douglas DC-6 aircraft.

Compliance required within 300 hours in service after the effective date of this AD, unless previously accomplished within 1700 hours in service prior to the effective date of this AD, and every 2000 hours in service thereafter.

To preclude the possibility of blade failure due to an undetected crack, accomplish the following in accordance with the propeller manufacturer's instructions contained in FAA approved Curtiss-Wright Corporation Service Publications S-242A-550 dated December 1, 1961, S-3B3-550 dated March 1, 1962, Chapter 63.2-2 as revised to May 1, 1962, and Chapter 63.2-4 as revised to November 1, 1964, or equivalent procedures and methods for inspection approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region:

(a) Remove propeller from aircraft and remove blades from hub.

(b) Remove the electrical de-icing heating elements or fluid anti-icing shoes.

(c) Inspect the entire blade surface and the entire internal blade shank area for cracks using the magnetic particle inspection method. When inspecting the internal blade area, visually examine the entire accessible bondline for cracks or separations using a borescope device or a mirror and light combination.

(d) Reject blades with "Indications" as defined in Curtiss-Wright Corporation Service Publication Chapter 63.2-4, paragraph 6. Replace with blades which have been inspected pursuant to this airworthiness directive.

(e) Reassemble acceptable blades and return to service.

Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection interval specified in this AD. This amendment is effective July 23, 1976.