Airworthiness Directive · Amendment 39-15691 · Dowty Propellers R408 Series Propellers
Dowty Propellers R408 Series Propellers
This AD applies to Dowty Propellers model R408/6-123-F/17 propellers with blades, part numbers (P/Ns) 697071200-18, 697071210-18, 697071227-18, 697071240-18, 697071245-18, or 697071257-18, installed. These propellers are installed on, but not limited to, Bombardier, Inc. (formerly de Havilland Canada) models DHC-8-400, DHC-8-401, and DHC-8-402 series airplanes.
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: Three in-service propellers have been found to have blades which have lost the bonded metallic leading edge guard. If the leading edge guard comes off as the propeller turns, it could cause secondary damage to aircraft or injury to personnel. For the reasons described above, EASA issued Emergency AD 2007-0223-E to require repetitive inspections of the blade Leading Edge (L/E) guards for correct bonding until they accumulate more than 1,200 flight hours (FH) time in service. This AD requires actions that are intended to address the unsafe condition described in the MCAI, which could result in the loss of the bonded metallic leading edge guard, and could result in damage to the airplane or injury to personnel.
Unless already done, do the following actions.
(1) Within the next 50 FH or within 1 month after the effective date of this AD, whichever occurs first, inspect all the concerned blade assemblies where the bonded metallic L/E guard has accumulated 1,200 FH or less since installation, in accordance with the instructions of Dowty Propellers ASB No. D8400-61-A69;
(2) Within 50 FH or 1 month after installing a replacement blade, inspect the concerned blade assembly where the bonded metallic L/E guard has accumulated 1,200 FH or less since installation, in accordance with the instructions of Dowty Propellers ASB No. D8400-61-A69;
(3) After the inspection as required by paragraph (1) or (2) of this AD, as applicable, at intervals not to exceed 100 FH, repeat the inspection of the concerned blade assemblies in accordance with the instructions of Dowty Propellers ASB No. D8400-61-A69 until the bonded blade L/E guard has accumulated more than 1,200 FH since installation;
(4) When, during any of the inspections as required by paragraphs (1), (2) or (3) of this AD, disbonding is found, apply the criteria as indicated in Appendix A of Dowty Propellers ASB No. D8400-61-A69 Revision 1 and, within the associated time period, repair or replace the affected blade assembly, as necessary, in accordance with the instructions of Dowty Propellers ASB No. D8400-61-A69 Revision 1.
(f) Blades that have been repaired within the first 101.6 mm (4.0 inches) of the tip of the blade as specified in Appendix D of the referenced ASB are allowed to continue in service for another 500 FH after accomplishment of the repair. Repair does not terminate the repetitive inspection requirements of paragraph (e)(3) of this directive.
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
