Airworthiness Directive · Amendment 39-16807 · Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies
Dowty Propellers Type R212/4-30-4/22 and R251/4-30-4/49 Propeller Assemblies
This AD applies to Dowty Propellers type R212/4-30-4/22 propeller assemblies with hub and driving center assembly part number (P/N) 601022105, 601022211, 601022294, 601021426, 601021858, or 601021859 installed, and type R251/4-30-4/49 propeller assemblies with hub and driving center assembly P/N 660207202 or P/N 660207203 installed.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Unless already done, do the following:
(1) Within 500 flight hours after the effective date of this AD, and thereafter at intervals not exceeding 500 flight hours, inspect the buttress threads in the propeller hub and driving center assembly for cracks.
(2) Use paragraphs 2.A.(1) through 2.A.(4)(a) of Accomplishment Instructions of Dowty Propellers Alert Service Bulletin No. 61-1043, Revision 7, dated March 1, 2011, and NDT Technique NDT 175U (Appendix A of Dowty Propellers Alert Service Bulletin No. 61-1043, Revision 7, dated March 1, 2011), to do the inspection.
(3) If a crack is found, remove the propeller assembly from service before further flight.
(4) After the effective date of this AD, do not install this propeller on any airplane unless the propeller hub and driving center has passed the inspections required by this AD.
This AD differs from the service information as follows:
(1) Although the service bulletin tells you to return the affected parts to the manufacturer, this AD does not require that action.
(2) Although the service bulletin tells you to submit information to the manufacturer, this AD does not require that action.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Propellers
