Document Headings

                    Document headings vary by document type but may contain                    the following:                  
                -                       the agency or agencies that issued and signed a document                    
                -                       the number of the CFR title and the number of each part                      the document amends, proposes to amend, or is directly                      related to                    
                -                       the agency docket number / agency internal file number                    
                -                       the RIN which identifies each regulatory action listed in                      the Unified Agenda of Federal Regulatory and Deregulatory                      Actions                    

                    See the                                          Document Drafting Handbook                                        for more details.                  

###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2017-1126; Product Identifier 2017-SW-125-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to supersede Airworthiness Directive (AD) 97-26-03 for Eurocopter Deutschland GmbH Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. AD 97-26-03 requires visual inspections for cracks in the ribbed area of the main rotor (M/R) mast flange (flange). Since we issued AD 97-26-03, we have determined that a certain reinforced M/R mast is not affected by the unsafe condition. This proposed AD would retain the requirements of AD 97-26-03 and would remove a certain M/R mast from the applicability. The actions of this proposed AD are intended to address an unsafe condition on these products.

# DATES:

We must receive comments on this proposed AD by November 13, 2018.

# ADDRESSES:

You may send comments by any of the following methods:
      -  Federal eRulemaking Docket:                          Go to                          http://www.regulations.gov.                          Follow the online instructions for sending your comments electronically.                    
      -  Fax:                          202-493-2251.                    
      -  Mail:                          Send comments to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.                    
      -  Hand Delivery:                          Deliver to the “Mail” address between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                    

## Examining the AD Docket

                    You may examine the AD docket on the internet at                     *http://www.regulations.gov*                     by searching for and locating Docket No. FAA-2017-1126; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the European Aviation Safety Agency (EASA) AD, the economic evaluation, any comments received and other information. The street address for Docket Operations (telephone 800-647-5527) is in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                

                    For service information identified in this proposed rule, contact Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at                     *http://www.helicopters.airbus.com/​website/​en/​ref/​Technical-Support_​73.html.*                     You may review this referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.                

# FOR FURTHER INFORMATION CONTACT:

                        Matt Fuller, Senior Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email                         *matthew.fuller@faa.gov.*

# SUPPLEMENTARY INFORMATION:

## Comments Invited

We invite you to participate in this rulemaking by submitting written comments, data, or views. We also invite comments relating to the economic, environmental, energy, or federalism impacts that might result from adopting the proposals in this document. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit only one time.

We will file in the docket all comments that we receive, as well as a report summarizing each substantive public contact with FAA personnel concerning this proposed rulemaking. Before acting on this proposal, we will consider all comments we receive on or before the closing date for comments. We will consider comments filed after the comment period has closed if it is possible to do so without incurring expense or delay. We may change this proposal in light of the comments we receive.

## Discussion

We issued AD 97-26-03, Amendment 39-10246 (62 FR 65750, December 16, 1997) (AD 97-26-03) for Eurocopter Deutschland GmbH (now Airbus Helicopters Deutschland GmbH) Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. AD 97-26-03 requires visual inspections for cracks in the ribbed area of the M/R flange and replacing the M/R mast if a crack is found. AD 97-26-03 was prompted by AD 97-276, effective September 25, 1997, issued by Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, to correct an unsafe condition for Eurocopter Deutschland GmbH Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. The LBA AD required immediate and repetitive inspections for a crack in the flange area after an M/R mast was found to have cracks “of critical magnitude.” When LBA AD 97-276 was issued, the cause of the cracks was under investigation. The actions of AD 97-26-03 are intended to detect cracks in the flange, which could result in failure of the flange and subsequent loss of helicopter control.

## Actions Since AD 97-26-03 Was Issued

Since we issued AD 97-26-03, EASA, which is the Technical Agent for the Member States of the European Union, issued EASA AD No. 2017-0193, dated September 29, 2017, to supersede the LBA AD. EASA advises that reinforced M/R mast part number (P/N) 4639 305 095, which is part of M/R mast assembly P/N 4639 205 016, is not affected by the unsafe condition. The EASA AD retains the repetitive inspection requirements but only for helicopters with M/R mast P/N 4639 305 002.

Also, since we issued AD 97-26-03, Eurocopter Deutschland GmbH Helicopters changed its name to Airbus Helicopters Deutschland GmbH. This proposed AD reflects that change and updates the contact information to obtain service documentation.

                    Additionally, the FAA's Aircraft Certification Service has changed its                           ( print page 46427)                        organizational structure. The new structure replaces product directorates with functional divisions. We have revised some of the office titles and nomenclature throughout this proposed AD to reflect the new organizational changes. Additional information about the new structure can be found in the Notice published on July 25, 2017 (82 FR 34564).                

## FAA's Determination

These helicopters have been approved by the aviation authority of Germany and are approved for operation in the United States. Pursuant to our bilateral agreement with Germany, EASA, its technical representative, has notified us of the unsafe condition described in its AD. We are proposing this AD because we evaluated all known relevant information and determined that an unsafe condition is likely to exist or develop on other products of the same type design.

## Related Service Information Under 1 CFR Part 51

We reviewed Airbus Helicopters Alert Service Bulletin No. ASB MBB-BK117-10-114, Revision 1, dated July 28, 2017. This service information specifies visually inspecting the area of the holes on the underside of the flange for cracks, especially in the ribbed area between the holes, and if cracks are found, contacting Airbus Helicopters Deutschland GmbH before further flight for advice on how to proceed. This service information applies to helicopters with M/R mast assembly P/N 4639205011.

                    This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the                     **ADDRESSES**                     section.                

## Other Related Service Information

We also reviewed Eurocopter Alert Service Bulletin No. ASB MBB-BK117-10-114, dated August 27, 1997, which specifies visually inspecting the area of the holes on the underside of the flange for cracks, especially in the ribbed area between the holes, and if cracks are found, contacting Eurocopter Helicopter Deutschland GmbH before further flight for advice on how to proceed. This service information applies to helicopters with M/R mast assembly P/N 4639205011 or 4639205016.

## Proposed AD Requirements

This proposed AD would require before further flight and thereafter at intervals not to exceed 100 hours time-in-service, visually inspecting the flange in the ribbed area for a crack using a 5-power or higher magnifying glass. If a crack exists, this proposed AD would require removing the M/R mast before further flight and replacing it with an airworthy M/R mast.

## Differences Between This Proposed AD and the EASA AD

The EASA AD requires contacting Airbus Helicopters if a crack is found on the flange for applicable instructions, whereas this proposed AD would require replacing the M/R mast with an airworthy M/R mast before further flight.

## Costs of Compliance

We estimate that this proposed AD would affect 62 helicopters of U.S. Registry and that labor costs average $85 per work-hour. Based on these estimates, we expect the following costs:
    - Visually inspecting the flange for a crack would require .25 work-hour and no parts for a cost of about $21 per helicopter and $1,302 for the U.S. fleet per inspection cycle.
    - Replacing the M/R mast would require 10 work-hours and parts would cost $50,000 for a cost of $50,850 per helicopter.

## Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

## Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed, I certify 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);

3. Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction; and

4. 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 proposed AD and placed it in the AD docket.

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Incorporation by reference
      - Safety

## The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 97-26-03, Amendment 39-10246 ( 62 FR 65750, December 16, 1997), and adding the following new AD:

**Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GmbH):**                         Docket No. FAA-2017-1126; Product Identifier 2017-SW-125-AD.                    

## (a) Applicability

This AD applies to Airbus Helicopters Deutschland GmbH (previously Eurocopter Deutschland GmbH) Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters, certificated any category, with a main rotor (M/R) mast assembly part number (P/N) 4639 205 011 installed.

## (b) Unsafe Condition

This AD defines the unsafe condition as a crack in a M/R mast flange. This condition could result in failure of the mast flange and subsequent loss of helicopter control.

## (c) Affected ADs

                        This AD replaces AD 97-26-03, Amendment 39-10246 (62 FR 65750, December 16, 1997).                              ( print page 46428)    

## (d) Comments Due Date

We must receive comments by November 13, 2018.

## (e) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.

## (f) Required Actions

(1) Before further flight, and thereafter at intervals not to exceed 100 hours time-in-service, visually inspect the flange in the ribbed area for cracks using a 5-power or higher magnifying glass in accordance with paragraphs 2.A.1 and 2.A.2 of the Accomplishment Instructions in Airbus Helicopters Alert Service Bulletin No. ASB-MBB-BK 117-10-114, Revision 1, dated July 28, 2017.

(2) If a crack is found as a result of the inspections specified in paragraph (f)(1) of this AD, remove the cracked M/R mast and replace it with an airworthy M/R mast.

## (g) Credit for Previous Actions

Actions accomplished before the effective date of this AD in accordance with the procedures specified in AD 97-26-03, dated December 16, 1997, are acceptable for compliance with the corresponding actions specified in paragraphs (f)(1) and (f)(2) of this AD.

## (h) Special Flight Permit

A special flight permit will not be permitted.

## (i) Alternative Methods of Compliance (AMOCs)

                        (1) The Manager, Safety Management Section, Rotorcraft Standards Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Matt Fuller, Senior Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email                         *9-ASW-FTW-AMOC-Requests@faa.gov.*

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

## (j) Additional Information

                        (1) Airbus Helicopters Alert Service Bulletin No. ASB MBB-BK 117-10-114, dated August 27, 1997, which is not incorporated by reference, contains additional information about the subject of this AD. For service information identified in this AD, contact Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at                         *http://www.helicopters.airbus.com/​website/​en/​ref/​Technical-Support_​73.html.*                         You may review a copy of the service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.                    

                        (2) The subject of this AD is addressed in European Aviation Safety Agency (EASA) AD No. 2017-0193, dated September 29, 2017. You may view the EASA AD on the internet at                         *http://www.regulations.gov*                         in the AD Docket.                    

## (k) Subject

Joint Aircraft Service Component (JASC) Code: 6300, Main Rotor Drive System.

Issued in Fort Worth, Texas, on August 29, 2018.

Scott A. Horn,

Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2018-19737 Filed 9-12-18; 8:45 am]

 BILLING CODE 4910-13-P