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Federal Register / Vol. 86, No. 34 / Tuesday, February 23, 2021 / Rules and Regulations apply to all GE GEnx1B64, 1B64/P1, 1B64/P2, 1B67, 1B67/P1, 1B67/P2, 1B70, 1B70/75/P1, 1B70/75/P2, 1B70/P1, 1B70/P2, 1B70C/P1, 1B70C/P2, 1B74/75/P1, 1B74/75/P2, 1B76/P2, and 1B76A/P2 model turbofan engines. The NPRM published in the Federal Register on July 20, 2020
85 FR 43752. The NPRM was prompted by a report of a crack in the outer fuel manifold causing fuel leakage.
In the NPRM, the FAA proposed to require initial and repetitive visual inspections of the p-clamp and, depending on the results of the inspection, a spot FPI of the outer fuel manifold. Depending on the results of the FPI, the NPRM proposed to require replacement of the outer fuel manifold.
The NPRM also proposed to require initial and repetitive replacements of the p-clamp. The FAA is issuing this AD
to address the unsafe condition on these products.

GE GEnx1B Service Bulletin SB 73
0080 R01, dated August 29, 2019, references GE GEnx1B SB 730053 for instructions to replace the outer fuel manifold. GE noted that GE GEnx1B
SB 730053 estimates that two hours are needed to replace the outer fuel manifold. GE stated that the discrepancy between the NPRM and service information could cause confusion or lead operators to opt to remove the engine to perform the outer fuel manifold replacement.
The FAA agrees. The FAA changed the estimated labor hours for replacing the outer fuel manifold in the OnCondition Costs section of this AD from 250 work hours to 2 work hours. The FAA also changed the estimated cost per product for replacing the outer fuel manifold in the On-Condition Costs section of this AD from $39,650 to $18,570, which reflects the reduction in labor hours.

Discussion of Final Airworthiness Directive
Request To Allow Use of Later Revisions of Service Information AAL and UAL requested that the FAA
add the phrase or later when referencing the service information in this AD. AAL stated that the manufacturer indicated that the service information is intended only to be a containment measure. Specifying or later could prevent numerous requests for Alternative Methods of Compliance if the manufacturer revises the service information. UAL stated that the manufacturer is developing a terminating action and, as a result, a revision to the service information is expected.
The FAA disagrees with adding language that allows the use of later revisions of the service information when performing the required actions of this AD. Later revisions of the service information have not been published by the manufacturer or reviewed by the FAA.

Comments The FAA received comments from six commenters. The commenters were Air Lines Pilots Association, International ALPA; American Airlines AAL;
Boeing Commercial Airplanes Boeing;
GE Aviation GE; Ethiopian Airlines;
and United Airlines UAL. One commenter requested changes to paragraph g, Required Actions, of this AD and to On-Condition Costs. Two commenters requested a change to compliance that was not implemented.
Two commenters requested clarification of the AD requirements. Four of the six commenters expressed support for the AD. The following presents the comments received on the NPRM and the FAAs response to each comment.
Request To Add Affected P-Clamp Significant Item Number SIN
GE requested that the FAA update paragraph g, Required Actions, of this AD to include the affected p-clamp SIN
when the p-clamp is referenced. GE
recognized that the p-clamp SIN is defined in paragraph h, Definition, of this AD. However, GE reasoned that as there are multiple p-clamps to be inspected per GEnx1B Engine Manual, 052100, MANDATORY INSPECTION, listing the p-clamp SIN in paragraph g of this AD avoids confusion.
The FAA agrees to include the pclamp SIN in paragraph g of this AD.
Request To Update On-Condition Cost GE requested that the FAA revise the replacement of the outer fuel manifold in On-Condition Costs from 250 work hours to 2 work hours. GE reasoned that
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Request To Clarify Sending the Outer Fuel Manifold for Repair AAL requested that the FAA clarify if the removed outer fuel manifold needs to be sent for repair. AAL cited references within paragraph 3.B.4b of GE GEnx1B SB 730080 R01, dated August 29, 2019, that instructs operators to send removed outer fuel manifolds for repair.
The FAA agrees that sending a removed outer fuel manifold for repair, as stated in paragraph 3.B.4b of GE
GEnx1B SB 730080 R01, dated August 29, 2019, is not mandated by this AD. This AD addresses the unsafe condition by requiring the removal of an outer fuel manifold if a crack or a sign
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of leakage is found and replacing it with a part eligible for installation. This AD
does not require sending an outer fuel manifold removed in accordance with paragraph g2i of this AD for repair.
The FAA clarified this by adding paragraph i, No Repair Requirement, to this AD.
Request To Clarify if Need To Comply Again Ethiopian Airlines asked if operators who inspected and replaced the affected p-clamp using GE GEnx1B SB 730080
R01, dated August 29, 2019, before the effective date of this AD, need to comply again.
If operators performed the initial visual inspection and replacement of the p-clamp as required by paragraphs g1 and 3 of this AD before the effective date of this AD, then these actions meet the initial visual inspection and replacement requirements of this AD. Paragraph f, Compliance, of this AD requires compliance with this AD within the times specified, unless already done. If the initial visual inspection and replacement of the p-clamp was already performed prior to the effective date of this AD, operators must perform the repetitive inspections, follow-onactions, and replacements of the pclamp required by paragraphs g1i, 2, and 3 of this AD using the stated compliance intervals.
Support for the AD
AAL, ALPA, Boeing, and UAL
expressed support for the AD.
Conclusion The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed.
Accordingly, the FAA is issuing this AD
to address the unsafe condition on these products. Except for minor editorial changes and any other changes described previously, this AD is adopted as proposed in the NPRM.
None of the changes will increase the economic burden on any operator.
Related Service Information Under 1
CFR Part 51
The FAA reviewed GE GEnx1B SB
730080 R01, dated August 29, 2019.
This SB describes procedures for replacing the p-clamp located at the signal fuel tube hose, SIN 34200, and instructions for removing the signal fuel tube hose when a p-clamp is found damaged or missing. This service information is reasonably available because the interested parties have access to it through their normal course
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