AD 2008-21-07

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.

Final rule; request for comments.

2008-21-07 Dowty Propellers (Formerly Dowty Aerospace Propellers): Amendment 39-15691; Docket No. FAA-2008-1088; Directorate Identifier 2008-NE-15-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective October 31, 2008.

Affected ADs

(b) None.

Applicability

(c) 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.

Reason

(d) 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, which could result in damage to the airplane or injury to personnel.

Actions and Compliance

(e) 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 sinceinstallation, 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 areallowed 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.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, Boston Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.
(2) Special Flight Permits: We are prohibiting special flight permits.

Related Information

(h) Refer to MCAI Airworthiness Directive 2007-0223, Revision 2, dated October 26, 2007, and Dowty Propellers Alert Service Bulletin (ASB) D8400-61-A69, dated August 15, 2007 or Revision 1, dated September 18, 2007, for related information.
(i) Contact Terry Fahr, Aerospace Engineer, Boston Aircraft Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: terry.fahr@faa.gov; telephone (781) 238-7155; fax (781) 238-7170, for more information about this AD.

Material Incorporated by Reference

(j) You must use the service information specified in Table 1 of this AD to do the actions required by this AD, unless the AD specifies otherwise.
(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this AD, contact Dowty Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL2 9QN, UK; Telephone 44 (0) 1452 716000; fax 44 (0) 1452 716001.
(3) You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http:// www.archives.gov/federal-register/cfr/ibr-locations.html.

Table1--Material Incorporated by Reference

Alert Service Bulletin No.
Page
Revision
Date

1
1
September 18, 2007.

2
Original
August 15, 2007.

3
1
September 18, 2007.
D8400-61-A69, Total Pages--4.
4
Original
August 15, 2007.

1
1
September 18, 2007.
D8400-61-A69, Appendix A, Total Pages--4.
2 to 4
Original
August 15, 2007.
D8400-61-A69, Appendix B, Total Pages--1.
All
Original
August 15, 2007.
D8400-61-A69, Appendix C, Total Pages--3.
All
Original
August 15, 2007.
D8400-61-A69, Appendix D, Total Pages--2
All
1
September 18, 2007.

Discussion

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2007-0223 R2, dated October 26, 2007, (referred to after this as "the MCAI''), to correct an unsafe condition for the specified products. The MCAI states:

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 FH time in service. Revision 1 of this AD was issued to clarify the required inspections and follow-up actions depending on findings and to make reference to the latest Dowty AlertService Bulletin (ASB) revision.

This AD has been further revised for clarification, specifying that blades repaired at the tip are only allowed to continue up to 500 hours in service after repair. This limitation was already in the Dowty ASB and the Note is added to the AD to avoid the impression that the AD does not require the same limitation.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Dowty Propellers has issued Alert Service Bulletins D8400-61-A69, dated August 15, 2007; and Revision 1, dated September 18, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This AD

This product has been approved by the aviation authority of the United Kingdom, and is approved for operation in the United States. Pursuant to our bilateral agreement with the United Kingdom, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all information provided by the United Kingdom and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because the required compliance time to detect the unsafe condition is too short for public comment. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2008-1088; Directorate Identifier 2008-NE-15-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority.We are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this AD:
1. Is not a "significant regulatory action'' under Executive Order 12866;
2. Is not a "significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new AD: