# AD 99-20-12: Bracket P/N 369F5190-1 - Type: Airworthiness directive - Status: Current - Products: MD Helicopters 369D, 369E, 369FF, 500N and 600N - Effective: November 4, 1999 - Published: September 30, 1999, 64 FR 52649–52650 - Issued: September 22, 1999 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-11342 - Docket: 98-SW-80-AD - Registered aircraft: 548 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/83/94/83948920aec0b68b921658c2f94a100d8b26a0318ce3212616327bc97e1eee72 (from https://www.govinfo.gov/content/pkg/FR-1999-09-30/pdf/99-25375.pdf) - Federal Register: https://www.federalregister.gov/documents/1999/09/30/99-25375/airworthiness-directives-md-helicopters-inc-model-369d-d369e-369ff-500n-and-600n-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/245D4310C2B87FDB86256A4D00636615.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/99-20-12 ## Summary This amendment adopts a new airworthiness directive (AD), applicable to MD Helicopters, Inc. Model 369D, 369E, 369FF, 500N, and 600N helicopters, that requires replacing the oil cooler blower bracket (bracket). This amendment is prompted by three reports of cracked brackets. The actions specified by this AD are intended to prevent failure of a bracket, loss of cooling of engine oil and transmission oil, and a subsequent forced landing. ## The airworthiness directive AD 99-20-12 MD HELICOPTERS, INC. (MDHI): Amendment 39-11342. Docket No. 98-SW-80-AD. Applicability: Model 369D, 369E, 369FF, 500N, and 600N helicopters, with oil cooler blower bracket (bracket), part number (P/N) 369F5190-1, installed, certificated in any category. NOTE 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required within 100 hours time-in-service, unless accomplished previously. To prevent failure of a bracket, loss of cooling of engine oil and transmission oil, and a subsequent forced landing, accomplish the following: (a) Remove the bracket, P/N 369F5190-1, and replace it with an airworthy bracket, P/N 369F5194-1. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office. (c) Special flight permits may beissued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. (d) This amendment becomes effective on November 4, 1999. ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to MD Helicopters Inc. Model 369D, 369E, 369FF, 500N, and 600N helicopters was published in the Federal Register on June 23, 1999 (64 FR 33447). That action proposed to require replacing the bracket. Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed. The FAA estimates that 100 helicopters of U.S. registry will be affected by this AD, that it will take approximately 2.5 work hours per helicopter to replace the bracket, and that the average labor rate is $60 per work hour. Required parts will cost approximately $225 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $37,500. The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for thisaction and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. Adoption of the Amendment 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: 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. 39.13 [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: ## 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 5 of 12 models: 369D, 369E, 600N, 369FF, 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: 548 (548 by airframe model, 0 by engine model) - Makers: Hughes Helicopters 241, MD Helicopters 161, Mcdonnell Douglas Helicopter 124, Mcdonnell Douglas Heli 17, Summa 4, Mcdonnell Douglas Mdhs 1 Models with the most aircraft: - [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d): 207 aircraft (airframe model) - [MD Helicopters 369FF](https://openairdocs.org/model/md-helicopters-369ff): 94 aircraft (airframe model) - [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e): 83 aircraft (airframe model) - [MD Helicopters 369E](https://openairdocs.org/model/md-helicopters-369e): 42 aircraft (airframe model) - [Hughes Helicopters 369E](https://openairdocs.org/model/hughes-helicopters-369e): 29 aircraft (airframe model) - [Mcdonnell Douglas Helicopter 500N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-500n): 27 aircraft (airframe model) - [Mcdonnell Douglas Heli 369FF](https://openairdocs.org/model/mcdonnell-douglas-heli-369ff): 17 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) - [Hughes Helicopters 369FF](https://openairdocs.org/model/hughes-helicopters-369ff): 5 aircraft (airframe model) - [Summa 369D](https://openairdocs.org/model/summa-369d): 4 aircraft (airframe model) - [Mcdonnell Douglas Mdhs 369E](https://openairdocs.org/model/mcdonnell-douglas-mdhs-369e): 1 aircraft (airframe model) All 15 models: https://openairdocs.org/ad/99-20-12/models.md Every aircraft: https://openairdocs.org/ad/99-20-12/aircraft.md ## Related documents - [Proposed rule 98-SW-80-AD](https://openairdocs.org/proposed/98-SW-80-AD): Notice of proposed rulemaking (NPRM), published Jun 23, 1999 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.