TITLE 14

- AERONAUTICS AND SPACE CHAPTER I - FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (Airworthiness Docket No. 75-SW-64, Amdt. 39-2457) PART 39

- AIRWORTHINESS DIRECTIVES BELL MODELS 204B,205A-~AND 212 HELICOPTERS
Aproposal to amend Part 39 of the Federal AviationRegulations to include an airworthiness directive imposing a periodic inspection, sealing, and refinishing ofmain rotor blades to prevent possible cracks d.ue to corrosionon Bell Models 204B, 205A-l, and 212 helicopters was published in L~O F.R. 46320. Interested persons have been afforded anopportunity to participate j_n themaking of this amendment. Only one conunent was received. An operator stated that stripping and painting would be difficult and unwarranted for certainoperators and might result in additional damage to the blade. Bell Helicopter Company revised their service bulletins to require partial stripping and refinishing only if repair or rework is accomplished. The FAA. agrees with this change to relax the initial requirements and the adopted rule requires compliance with the revised servicebulletins. In considerationof the foregoing, and pursuant to the authority delegated to me by the Administrator (31 F.R. 13697), Section 39.13 of Part 39 of the Feder.al AviationRegulations is amended by adding the following new airworthiness directive: BELL. Applies to Bell Models 204B, 205A-l, and 212 helicopters certificated in all categories.2 (a) Compliance required as follows: (1) For main rotor blades having 12 or more 1ronths• installed time on a helicopter, on the effective date of this AD, conduct inspections within 90 days' time unless already accomplished. (2) For main rotor blades having less than 12 months 1 installed time on a helicopter on the effective date of this AD, conduct inspections prior to attaining 15 months' installed time on a helicopter
. (3) Conduct repetitive inspections at intervals not to exceed 12 months' installed time from the last inspection. (b) To detect possible cracks and corrosion and to prevent further corrosion in the main rotor blade inboard portion, accomplish the following:(1) Remove themain rotor blades from the helicopter and prepare the blades for inspection as noted in Bell Helicopter Company Service BulletinNo
. 205-75-5, revision A, dated October 22, 1975, or later approved revisions, Part III, paragraph A
. (2) Inspect the blades as noted in Service Bulletin No. 205-75-5, revision A, or later approved revisions, Part III, paragraph A. Blades with cracks or adhesive voids exceeding the limits specified in Service BulletinNo. 205-75-5, revisionA, Part III, paragraph A, may not be returned to service. (3) Repair discrepant blades as specified in Service Bulletin No. 205-75-5, revision A, or later approved revisions, Part III, paragraph A, Refinish discrepant blades as specified :i.n Part III, paragraph B,3 (4) Install blades on thehelicopter in accordance with the applicablemodel maintenance and overhaul informationmanual and balance and track the blades. (c) Equivalent means of compliance with paragraph (b) of this AD may be approved by the Chief, Engineering andManufacturing Branch, Flight Standards Division, Southwest Region, Federal AviationAdministration, Fort Worth, Texas. Bell Service Bulletins No. 20l1-75-1, revisionA, dated October 22, 1975, No. 212-75-6, revision A, dated October 22, 1975, or later FAA-DER approved revisions to these bulletins
are approved as equivalent means of compliance with paragraph (b). (d) Upon request of the operator, anFAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, Flight Standards Division, FAA, Southwest
.Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. (e) The manufacturerIs specifications and procedures identified and described inthis directive are incorporated herein and made a part hereof pursuant to 5

## u.s.c. 552(a)(l). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Service Manager, Bell Helicopter Company, P.O. Box 482, Fort Worth, Texas 76101. These documents may also be examined at the Office of the Regional Counsel, Southwest Region, FAA, 4400 nlueMound Road, Fort Worth, Texas, and at FAA headquarters,

### 4 800 Independence Avenue, 

## s.w., Washington, 

## D.c. Ahistorical file on this AD which includes the incorporated material in full is maintained by the FM at its headquarters in Washington, O.C, , and at the Office of the Regional Counsel, Southwest Region, FM, 

### 4L~ oo Blue Mound Road, Fort worth, Texas
. This amendment becomes effective January 19, 1976. This amendment is made under the authority of Sections 313(a), 601, and 603 of the Federal Aviation Act of 1958 (L1

.9

## u.s.c. 1354(a), 1421, and 1L~23) and of Section 6(c) of the Department of Transportation Act (49

## u.s.c. 1655(c)). 

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# ~vv~/\-:.~,.,l'"°(c;: ._ Dir~ Southwest Region Issued in Fort Worth, Texas, on December 3, 1975
. The incorporation by reference provisions in this document were approved by the Director of the Federal Register on June 19, 1967.