Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all GE GEnx-1B64/P2, -1B67/ P2, -1B70/P2, -1B70C/P2, -1B70/75/P2, and -1B74/75/P2 turbofan engines with engine assembly, P/N 2447M10G01 or P/N 2447M10G02, installed. The NPRM published in the Federal Register on May 10, 2016 (81 FR 28777). The NPRM was prompted by a report of a significant fan rub event. The NPRM proposed to require rework of the engine fan stator module assembly. We are issuing this AD to prevent failure of the fan blades and the load reduction device, loss of power to one or more engines, loss of thrust control, and loss of the airplane.
Request To Add Terminating Action
Japan Airlines and United Airlines requested that the airplane flight manual (AFM) limitations mandated by AD 2016-08-12, Amendment 39-18488 (81 FR 23581, April 22, 2016) (``AD 2016-08-12''), be removed from an aircraft that has complied with the fan case grind procedure mandated in this AD. They reason that once the fan case grind is completed on both engines installed on an airplane, there is no longer an unsafe condition.
We agree. Once the fan case grind has been completed on both engines installed on an airplane, the unsafe condition no longer exists. With agreement from the Transport Airplane Directorate (TAD), we added a terminating action paragraph to this AD.
Request To Add Compliance Methods
Japan Airlines requested that alternate service documents be approved as compliance to AD 2016-06-08, Amendment 39-18439 (81 FR 14704, March 18, 2016) (``AD 2016-06-08''). They reason that the service documents provide the same procedure and the same post-rework configuration.
We disagree. AD 2016-06-08 is a separate AD issued by the TAD, which includes aircraft-level corrective actions. The commenter must contact the TAD to request a change to AD 2016-06-08. We did not change this AD.
Request ToChange Applicability
GE requested that the applicability explicitly state that engine assembly, P/N 2447M10G03, is not applicable to this AD. They reason that engine assembly, P/N 2447M10G03, is a new production part that does not contain the unsafe condition.
We disagree. Since engine assembly, P/N 2447M10G03, is not listed in the applicability of this AD, it is not applicable to this AD. We did not change this AD.
Request To Change Compliance Method
GE requested that another procedure included within a new service bulletin, GE GEnx-1B Service Bulletin (SB) 72-0317 R00, dated June 29, 2016, be added as a means of compliance to this AD. They reason that this new procedure achieves the same configuration as the proposed procedure.
We agree. The new procedure in GE GEnx-1B SB 72-0317 R00, dated June 29, 2016, also corrects the unsafe condition addressed in this AD. We added GE GEnx-1B SB 72-0317 R00, dated June 29, 2016, as a means of compliance in this AD.
Request To Change Compliance Time
GE requested that we move the action specified in paragraph (f) Credit for Previous Action, to compliance paragraph (e) of this AD. They reason that this action is an equivalent method of performing the fan case rework.
We agree. The action is equivalent to the current compliance, but located within a different service document. We revised paragraph (f) and paragraph (e) of this AD accordingly.
Request To Change Affected ADs
United Airlines requested that we list AD 2016-06-08 and AD 2016- 08-12 in this AD. They reason that AD 2016-06-08 and AD 2016-08-12 address the same unsafe condition as this AD and also mandate a fan case rework.
We agree. AD 2016-06-08 and AD 2016-08-12 address the same unsafe condition as this AD. We list AD 2016-06-08 and AD 2016-08-12 in paragraph (h) of this AD.
Request To Change Affected ADs
United Airlines requested that we supersede AD 2016-08-12 with this AD. They reason that AD 2016-06-08and AD 2016-08-12 address the same unsafe condition of the engine and mandate a fan case rework procedure.
We disagree. An AD that mandates engine-level corrective actions, ``this AD'', cannot supersede an AD, ``AD 2016-08-12'' that mandates aircraft-level corrective actions. AD 2016-08-12 mandates aircraft limitations in addition to the engine rework procedure that can only be mandated at the aircraft level, not the engine level. We did not change this AD.
Request To Change Operating Procedures
United Airlines requested that we revise the operating procedures that require the ice removal procedure to be done every 5 minutes, rather than the preferred every 5 minutes or less, allowing the pilot to do the procedure prior to 5 minutes after Engine Indication and Crew Alerting System (EICAS) notification. United Airlines suggests the 5 minute requirement does not allow pilots to effectively manage the cockpit within reasonable parameters or room to operate.
We disagree.The AFM operating procedures are mandated by aircraft- level AD 2016-06-08 and AD 2016-08-12, which were issued by the TAD. The commenter must contact the TAD to request a change to AD 2016-06-08 or AD 2016-08-12. We did not change this AD.
Request To Change Compliance Time
United Airlines requested that we allow installation of engine assembly, P/N 2477M10G03, by using GE GEnx-1B SB 72-0317 to modify the engine instead of using the fan grind rework procedure as compliance to AD 2016-08-12. They reason that the procedure in GE GEnx-1B SB 72-0317 achieves the same engine outcome as the currently mandated compliance.
We disagree. AD 2016-08-12 was issued by the TAD. The commenter must contact the TAD to request a change to AD 2016-08-12. We did not change this AD.
Conclusion
We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously. We havedetermined that these minor changes:
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.
We also determined that these changes will not increase the economic
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burden on any operator or increase the scope of this AD.
Related Service Information Under 1 CFR Part 51
We reviewed GE GEnx-1B SB 72-0314 R00, dated April 1, 2016. The SB describes procedures for increasing the clearance of the fan stator module assembly. We also reviewed GE GEnx-1B SB 72-0309 R00, dated March 11, 2016. That SB describes procedures for increasing the clearance of the fan stator module assembly. We also reviewed GE GEnx- 1B SB 72-0317 R00, dated June 29, 2016. That SB releases a new fan stator module assembly. 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.
Costs of Compliance
We estimate that this AD affects 89 engines installed on airplanes of U.S. registry. We also estimate that it will take about 40 hours per engine to comply with this AD. The average labor rate is $85 per hour. Based on these figures, we estimate the total cost of this AD to U.S. operators to be $302,600.
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
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 it justifies making a regulatory distinction, and
(4) Will not have asignificant 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.