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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 2000-SW-13-AD] 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

This NPRM proposes the supersedure of an existing airworthiness directive (AD) for Eurocopter France (ECF) Model SA.315B, SA.316B, SA.316C, SE.3160, and SA.319B helicopters. That AD requires initial and recurring inspections of the main rotor blade (blade) spar for cracks. This action would require initial and recurring dye penetrant or eddy current inspections for a cracked blade spar at 100-hour time-in-service (TIS) intervals or 600 cycles, whichever occurs first, rather than the 25-hour TIS intervals currently required. This proposal is prompted by an accident in which a Model SA.315B helicopter blade failed due to fatigue cracking. The proposed actions are intended to prevent separation of a blade and subsequent loss of control of the helicopter. 

# DATES:

Comments must be received on or before January 30, 2001. 

# ADDRESSES:

                        Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-13-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address:                         *9-asw-adcomments@faa.gov.*                         Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.                     

# FOR FURTHER INFORMATION CONTACT:

Jim Grigg, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5490, fax (817) 222-5961. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received. 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. 

                    Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this action must submit a self-addressed,                           ( print page 75199)                        stamped postcard on which the following statement is made: “Comments to Docket No. 2000-SW-13-AD.” The postcard will be date stamped and returned to the commenter.                 

## Availability of NPRMs 

You may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-13-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. 

## Discussion 

On August 21, 1998, the FAA issued AD 98-10-09, Amendment 39-10725 (63 FR 46160, August 31, 1998), to require inspecting the blade spar for cracks at 25-hour TIS intervals. That action was prompted by an accident in which a Model SA.315B helicopter blade spar failed due to fatigue cracking. That condition, if not corrected, could result in blade separation and subsequent loss of control of the helicopter. 

Since the issuance of that AD, we have determined that the initial and recurring inspections for a cracked blade spar should be accomplished by a dye penetrant or eddy current inspection at intervals of 100 hours TIS or 600 cycles, whichever occurs first. Eddy current and dye penetrant inspections are more reliable than visual inspections especially on the lower surface of the rotor blade where the blade's weight may close the crack. ECF has issued Service Bulletins (SB) SA 315 No. 05.39 and SA 316/319 No. 05.98, both dated November 12, 1999, specifying a check of the main rotor blade root spar for cracks. ECF has also issued SB 65.137R1, dated November 17, 1993, specifying running a sealant bead around the spar-to-fitting junction and inspecting for corrosion. After investigating a main rotor blade failure at the first cuff-to-spar assembly bolt, ECF redefined the interval for crack inspections on the spar and added another criterion (sudden occurrence of vibrations) that makes this inspection necessary. A sudden occurrence of a one-per-rev vibration could indicate a cracked blade. 

We have identified an unsafe condition that is likely to exist or develop on other ECF Model SA.315B, SA.316B, SA.316C, SE.3160, and SA.319B helicopters of these same type designs. The proposed AD would supersede the current AD and redefine the recurring inspection interval. The proposed AD will require, within 25 hours TIS and thereafter at intervals not to exceed 100 hours TIS or 600 cycles, whichever occurs first, inspecting each blade spar for a crack, using dye penetrant or eddy current, and inspecting each blade cuff to ensure an adequate sealant bead. A “cycle” is any landing, regardless of whether the main rotor rotation is continued or stopped, or any completion of an external load operation; e.g. load release. If a crack is found, the proposed AD would require replacing the blade with an airworthy blade before further flight. 

The FAA estimates that 93 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 4 hours to inspect and 4 hours to replace a blade, if necessary, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $66,960, assuming three inspections per year and no blade replacement. 

The regulations proposed herein would 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132. 

                    For the reasons discussed above, I certify that this proposed 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) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption                     **ADDRESSES.**

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: 

## The Proposed Amendment 

# 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

2. Section 39.13 is amended by removing Amendment 39-10725 (63 FR 46160), and by adding a new airworthiness directive (AD), to read as follows:

**Eurocopter France:**                                 Docket No. 2000-SW-13-AD. Supersedes AD 98-10-09, Amendment 39-10725, Docket No. 98-SW-23-AD.                            

*Applicability:*                                 Model SA.315B, SA.316B, SA.316C, SE.3160, and SA.319B helicopters with a main rotor blade (blade), with any of the following part numbers (P/N): 3160S11-10000 all dash numbers, 3160S11-30000 all dash numbers, 3160S11-35000 all dash numbers, 3160S11-40000 all dash numbers, 3160S11-45000 all dash numbers, 3160S11-50000 all dash numbers, or 3160S11-55000 all dash numbers, 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 as indicated, unless accomplished previously.                             

To prevent a blade separation and subsequent loss of control of the helicopter, accomplish the following: 

(a) Within 25 hours time-in-service (TIS) or before the next flight following the onset of any one-per-rev vibration, whichever occurs first, and thereafter at intervals not to exceed 100 hours TIS or 600 “cycles” (a “cycle” is any landing, regardless of whether the main rotor rotation is continued or stopped, or any completion of an external load operation; e.g. load release), whichever occurs first, 

(1) Inspect each blade spar for a crack. 

(i) Without removing the blade from the helicopter, clean each blade root area using “Teepol” or an equivalent product. 

(ii) Support the blade tip to eliminate blade droop while inspecting the lower blade surface. 

(iii) By either a dye penetrant or eddy current method, inspect each blade along the hatched area indicated in Figure 1, beginning on the blade lower surface, then on the flat section of the trailing edge (B), on the blade upper surface, and then on the flat section of the leading edge (A). 

# Note 2:

Eurocopter France Service Bulletins (SB) SA 315 No. 05.39 and SA 316/319 No. 05.98, dated November 12, 1999, pertain to the subject of this AD.

(iv) If a crack is found, replace the blade with an airworthy blade before further flight. 
      ( print page 75200)    
(2) Ensure that there is a sealant bead (1) around the edge of each blade cuff. If no sealant bead exists or if a sealant bead shows excessive wear, before further flight, apply a sealant bead in accordance with paragraph 2.2 of the Accomplishment Instructions of Eurocopter France SB 65.137R1, dated November 17, 1993. 

(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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group. 
      ( print page 75201)    

# Note 4:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(c) Special flight permits will not be issued. 

# Note 5:

The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 1998-171-039(A)R2 and 1998-170-056(A)R2, both dated January 12, 2000.

Issued in Fort Worth, Texas, on November 14, 2000. 

Michele M. Owsley, 

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. 

BILLING CODE 4910-13-P

[FR Doc. 00-30653 Filed 11-30-00; 8:45 am] 

BILLING CODE 4910-13-C