AD 2019-05-05

We are superseding 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 required 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 new AD retains the requirements of AD 97-26-03 and removes a certain M/R mast from the applicability. The actions of this AD are intended to address an unsafe condition on these products.

Final rule.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

0 2. The FAA amends Sec. 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:

2019-05-05 Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GmbH): Amendment 39-19587; 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 4639 205 011 installed.

(b) Unsafe Condition

This AD defines the unsafe condition as a crack in an 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).

(d) Effective Date

This AD becomes effective April 17, 2019.

[[Page 8965]]

(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, Amendment 39-10246 (62 FR 65750, 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 Docket No. FAA-2017-1126.

(k) Subject

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

(l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(i) Airbus Helicopters Alert Service Bulletin No. ASB MBB-BK117- 10-114, Revision 1, dated July 28, 2017.
(ii) [Reserved]
(3) For Airbus Helicopters service information identified in this AD, contact Airbus Helicopters, 2701N 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.
(4) You may view this service information at FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N- 321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.
(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to remove AD 97-26-03, Amendment 39-10246 (62 FR 65750, December 16, 1997) (AD 97-26-03) and add a new AD. AD 97-26-03 applied to 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 required visual inspections for cracks in the ribbed area of the M/R flange and replacing the M/R mast if a crack is found.
The NPRM published in the Federal Register on September 13, 2018 (83 FR 46426). The NPRM was prompted by EASA AD No. 2017-0193, dated September 29, 2017 (EASA AD 2017-0193), issued by EASA, which is the Technical Agent for the member States of the European Union. EASA AD 2017-0193 superseded 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. 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. EASA AD 2017-0193 retains the repetitive inspection requirements of the LBA AD but only for helicopters with M/R mast P/N 4639 305 002.
Since we issued AD 97-26-03, Eurocopter Deutschland GmbH Helicopters changed its name to Airbus

[[Page 8964]]

Helicopters Deutschland GmbH. This AD reflects that change and updates the contact information to obtain service documentation. Additionally, the FAA's Aircraft Certification Service has changed its organizational structure. The new structure replaces product directorates with functional divisions. We have revised some of the office titles and nomenclature throughout this AD to reflect the neworganizational changes. Additional information about the new structure can be found in the Notice published on July 25, 2017 (82 FR 34564).

Comments

We gave the public the opportunity to participate in developing this AD, but we did not receive any comments on the NPRM.

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 have reviewed the relevant information and determined that an unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

Differences Between This 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 AD requires replacing the M/R mast with an airworthy M/R mast before further flight.

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 4639 205 011.
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 4639 205 011 or 4639 205 016.

Costs of Compliance

We estimate that this AD affects 62 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD. Labor costs are estimated at $85 per work-hour.
Visually inspecting the flange for a crack requires 0.25 work-hour for an estimated cost of about $21 per helicopter and $1,302 for the U.S. fleet per inspection cycle. Replacing the M/R mast requires 10 work-hours and parts cost $50,000 for an estimated 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 have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 above, I certify that this AD:
(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),
(3) Will not affect intrastate aviation in Alaska to the extent that a regulatory distinction is required, 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.