AD 99-20-12

Airworthiness directive · Bracket P/N 369F5190-1 · MD Helicopters 369D, 369E, 369FF and 2 more

Effective
November 4, 1999
Published
September 30, 1999 · 64 FR 52649–52650
Issued
September 22, 1999
Models
369D, 369E, 369FF, 500N, 600N
Data sheet
TCDSH3WE
Registered aircraft
548 matched by model
Product
Aircraft · Rotorcraft
Amendment
39-11342
Docket
98-SW-80-AD
Issued as
Final rule

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. Only the govinfo PDF is the legal edition. DRS record last changed May 30, 2024.

On this page

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

The FAA’s background, reasoning and cost estimate, published with the AD.

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 TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 548

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Hughes Helicopters241 aircraft
  • MD Helicopters161 aircraft
  • Mcdonnell Douglas Helicopter124 aircraft
  • Mcdonnell Douglas Heli17 aircraft
  • Summa4 aircraft
  • Mcdonnell Douglas Mdhs1 aircraft
By year built
19762026
Registered aircraft by year built: 428 aircraft
19763
197727
197831
197927
198031
198137
198215
19837
19845
19857
19864
19878
19889
198914
199015
199111
199216
19937
19948
19952
19965
19976
19989
19992
200015
20014
20023
20031
20051
20065
20076
200816
200913
20104
20111
20127
20134
20144
20155
20161
20172
20182
20194
20204
20211
20223
20236
20248
20251
20261

120 with no year recorded

By model

Aircraft

See all 548 aircraft