# AD 2004-20-08: Forward and center thruster control cable assembly connector (connector) - Type: Airworthiness directive - Status: Current - Products: MD Helicopters 500N and 600N - Effective: October 21, 2004 - Published: October 6, 2004, 69 FR 59788–59790 - Issued: September 22, 2004 - Issued as: Final rule; request for comments - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-13813 - Docket: FAA-2004-19223 (https://www.regulations.gov/docket/FAA-2004-19223) - Project: 2004-SW-20-AD - Registered aircraft: 66 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/69/9b/699b0aa975cda40df9d8e919688541c7344cdc46834ee23041174c34075601bf (from https://www.govinfo.gov/content/pkg/FR-2004-10-06/pdf/04-22264.pdf) - Federal Register: https://www.federalregister.gov/documents/2004/10/06/04-22264/airworthiness-directives-md-helicopters-inc-mdhi-model-500n-and-600n-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/984B3ADFA4A1F5ED86256F2500530AEA.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/2004-20-08 ## Summary This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 500N and 600N helicopters. This action requires using a bright light and a 10× or higher magnifying glass to inspect each forward and center thruster control cable assembly connector (connector) for corrosion pitting or cracking. If you find corrosion pitting or cracking, this AD also requires replacing the cable assembly with an airworthy cable assembly before further flight. This amendment is prompted by a report of a failure of the forward thruster cable assembly due to stress corrosion. The actions specified in this AD are intended to detect a corrosion-pitted or cracked connector and prevent failure of the cable assembly and subsequent loss of control of the helicopter. ## The airworthiness directive Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: 2004-20-08 MD Helicopters, Inc.: Amendment 39-13813. Docket No. FAA-2004-19223; Directorate Identifier 2004-SW-20-AD. Applicability: The following model and serial number (S/N) helicopters, with forward thruster cable (cable) assembly and center cable assembly part number (P/N), installed, certificated in any category: | Model | S/N | Forward cable assembly P/N | Center cable assembly P/N | | --- | --- | --- | --- | | 500N | With a prefix of “LN” and 001 through 099 | 500N7201-55 | 500N7201-57 | | 600N | With a prefix of “RN” and 003 through 068 | 500N7201-55 | 500N7201-59 | Compliance: Required as indicated, unless accomplished previously. To detect a corrosion-pitted or cracked forward or center cable assembly connector (connector) and to prevent failure of the cable assembly and subsequent loss of control of the helicopter, accomplish the following: (a) Within the next 10 hours time-in-service or 30 days, whichever comes first, using a bright light and a 10X or higher magnifying glass, inspect each connector for corrosion pitting or cracking by following the Accomplishment Instructions, paragraph 2., of MD Helicopter, Inc. Service Bulletin SB500N-027, SB600N-042, dated May 3, 2004. If you find corrosion pitting or cracking, replace the cable assembly with an airworthy cable assembly before further flight. Replacing the cable assembly with an airworthy cable assembly is terminating action for the requirements of this AD. (b) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Los Angeles Aircraft Certification Office, FAA, for information about previously approved alternative methods of compliance. (c) Do the inspection by following MD Helicopters, Inc. Service Bulletin SB500N-027, SB600N-042, dated May 3, 2004. The Director of the Federal Register approved this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9734, telephone 1-800-388-3378, fax 480-891-6782, or on the Web at http://www.mdhelicopters.com. Copies may be inspected 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/code_of_federal_regulations/ibr_locations.html. (d) This amendment becomes effective on October 21, 2004. ## Rule preamble ### Dates Effective October 21, 2004. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 21, 2004. Comments for inclusion in the Rules Docket must be received on or before December 6, 2004. ### Addresses Use one of the following addresses to submit comments on this AD: • DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically; • Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically; • Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590; • Fax: (202) 493-2251; or • Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. You may get the service information identified in this AD from MD Helicopters, Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9734, telephone 1-800-388-3378, fax 480-891-6782, or on the Web at http://www.mdhelicopters.com. ### For further information contact John Cecil, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5228, fax (562) 627-5210. ### SUPPLEMENTARY INFORMATION This amendment adopts a new AD for the MDHI Model 500N and 600N helicopters. This action requires using a bright light and a 10× or higher magnifying glass to inspect each connector for corrosion pitting or cracking. If corrosion pitting or cracking is found, this AD also requires replacing the cable assembly with an airworthy cable assembly before further flight. This amendment is prompted by a report of a failure of a cable assembly due to a stress corrosion crack. The actions specified in this AD are intended to detect a corrosion-pitted or cracked connector and to prevent failure of a cable assembly and subsequent loss of control of the helicopter. We have reviewed MDHI Service Bulletin SB500N-027, SB600N-042, dated May 3, 2004 (SB). The SB describes procedures for inspecting the connectors on the forward and center cable assemblies for corrosion pitting or cracking. Also, the SB specifies replacing the cable assembly if corrosion pitting or cracking is found on the connectors. This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to detect a corrosion-pitted or cracked connector on a cable assembly and to prevent failure of the cable assembly, and subsequent loss of control of the helicopter. This AD requires a one-time inspection of the connectors on the cable assemblies for corrosion pitting or cracking. If corrosion pitting or cracking is found, this AD also requires replacing the cable assembly with an airworthy cable assembly before further flight. Accomplish the actions by following the SB described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability or structural integrity of the helicopter. Therefore, within the next 10 hours time-in-service or 30 days, whichever comes first, using a bright light and a 10X or higher magnifying glass, inspect each connector for corrosion pitting or cracking. If corrosion pitting or cracking is found, replacing the cable assembly with an airworthy cable assembly is required before further flight and this AD must be issued immediately. Inspecting each connector and replacing the cable assembly if corrosion pitting or cracking is found is terminating action for the requirements of this AD. Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. We estimate that this AD will affect 66 helicopters. The inspections will take about 1 work hour at an average labor rate of $65 per work hour. Required parts will cost about $4520 per helicopter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $4,290 assuming no parts will need to be replaced. ### Comments Invited This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19223; Directorate Identifier 2004-SW-20-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments. We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of our docket web site, you can find and read the comments to any of our dockets, including the name of the individual who sent the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov. We have 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 that the regulation: 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 an economic evaluation of the estimated costs to comply with this AD. See the DMS to examine the economic evaluation. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 2 of 12 models: 600N, 500N ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 66 (66 by airframe model, 0 by engine model) - Makers: Mcdonnell Douglas Helicopter 41, MD Helicopters 25 Models with the most aircraft: - [Mcdonnell Douglas Helicopter 500N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-500n): 27 aircraft (airframe model) - [Mcdonnell Douglas Helicopter 600N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-600n): 14 aircraft (airframe model) - [MD Helicopters 500N](https://openairdocs.org/model/md-helicopters-500n): 13 aircraft (airframe model) - [MD Helicopters 600N](https://openairdocs.org/model/md-helicopters-600n): 12 aircraft (airframe model) All 4 models: https://openairdocs.org/ad/2004-20-08/models.md Every aircraft: https://openairdocs.org/ad/2004-20-08/aircraft.md No proposed rule in this release led to it. Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.