Source: https://www.federalregister.gov/documents/2017/05/05/2017-07938/airworthiness-directives-the-boeing-company-airplanes
Timestamp: 2017-11-21 07:20:56
Document Index: 263101816

Matched Legal Cases: ['art 39', 'arts 1', 'art 1', 'art 2', 'art 1', 'art 2', 'art 4', 'art 5', 'art 4', 'art 5', 'art 6', 'art 7', 'art 6', 'art 7', 'art 6', 'art 7', '§\u200939', 'art 1', 'art 2', 'art 1', 'art 2', 'art 4', 'art 5', 'art 4', 'art 5', 'art 6', 'art 7', 'art 6', 'art 7', 'art 3', 'art 3']

We must receive comments on this SNPRM by June 19, 2017.
21146-21153 (8 pages)
Docket No. FAA-2016-3697
Directorate Identifier 2015-NM-143-AD
FAA-2016-3697
2015-NM-143-AD The Boeing Company Model 757-200, -200CB, and -300 series airplanes
SB-757-53-0097-03--BOEING
U.S. DOT/FAA - Cross Reference AD 2011-01-15
Request To Reduce the Compliance Threshold for Zone 1 Inspections
Request To Remove Certain Duplicate Language
Request To Clarify Zone 1 Inspection Language
Request To Clarify Optional Terminating Action
Request To Address the Possibility That Cracking May Have Been Found During Inspections Required by AD 2011-01-15
Request To Include Credit for Previous Inspections
Request To Clarify Certain Inspection Areas
Request To Clarify Sections in Service Information With Inspection Instructions
Request To Clarify Inspection Language
Request To Clarify the Repair Area
Request To Clarify the Description of the Preventative Modification
Request To Clarify Exceptions
Request To Clarify Certain AMOC Language
Concerns About Correcting Unsafe Condition
(h) Initial Compliance Time for Inspection Required by Paragraph (g)(1) of This AD
(i) Post-Preventive Modification Supplemental Inspections
(l) Exceptions to Service Information Specifications and Preventative Modification
https://www.federalregister.gov/d/2017-07938 https://www.federalregister.gov/d/2017-07938
We are revising an earlier proposed airworthiness directive (AD) that proposed to supersede AD 2011-01-15, which applies to certain The Boeing Company Model 757-200, -200CB, and -300 series airplanes. AD 2011-01-15 requires repetitive inspections for cracking of the fuselage skin of the crown skin panel along the chem-milled step at certain stringers, and repair, if necessary. This action revises the notice of proposed rulemaking (NPRM) by reducing the compliance time for certain inspections. We are proposing this AD to address the unsafe condition on these products. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.Start Printed Page 21147
For service information identified in this SNPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone 562-797-1717; Internet https://www.myboeingfleet.com. You may view this referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-3697.
You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-3697; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2016-3697; Directorate Identifier 2015-NM-143-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.
We issued an NPRM to amend 14 CFR part 39 to supersede AD 2011-01-15, Amendment 39-16572 (76 FR 1351, January 10, 2011) (“AD 2011-01-15”). AD 2011-01-15 applies to certain The Boeing Company Model 757-200, -200CB, and -300 series airplanes. AD 2011-01-15 requires repetitive inspections for cracking of the fuselage skin of the crown skin panel along the chem-milled step at stringers S-4L and S-4R, from station (STA) 297 through STA 439, and repair if necessary. AD 2011-01-15 also includes terminating action for the repetitive inspections of the repaired areas only. AD 2011-01-15 resulted from reports of cracking in the fuselage skin of the crown skin panel. The NPRM published in the Federal Register on February 18, 2016 (81 FR 8157) (“The NPRM”). The NPRM was prompted by reports of the initiation of new fatigue cracking in the fuselage skin of the crown skin panel along locally thinned channels adjacent to the chem-milled steps. The NPRM proposed to add repetitive inspections for cracking in additional areas and repair if necessary. The NPRM also proposed to remove airplanes from the applicability in AD 2011-01-15. The NPRM also proposed to add an optional skin panel replacement which would terminate all inspections and an optional preventative modification that would terminate certain inspections.
Since we issued the NPRM, we have received a report that cracking was found earlier than the compliance time specified for the Zone 1 inspections identified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015 (referenced in the NPRM as the appropriate source of service information for accomplishing the specified actions). Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, has been issued to reduce the compliance time for the Zone 1 inspections.
We reviewed Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. The service information describes procedures for repetitive external sliding probe eddy current (EC) and external spot-probe-medium-frequency EC inspections for cracking of the crown skin panel, repair, a preventive modification, and replacement of the crown skin panel. 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.
FedEx provided comments that support the intent of the NPRM. FedEx also stated that the inspection area is within the affected area of its passenger-to-freighter modification per supplemental type certificate (STC) ST03562AT. FedEx noted that ST Aerospace will apply for an alternative method of compliance (AMOC).
Boeing asked that we change paragraph (g)(1) of the proposed AD to reduce the compliance threshold for the Zone 1 inspections from 18,000 to 15,000 total flight cycles. Boeing stated that a grace period could be provided for airplanes that have exceeded 15,000 total flight cycles. Boeing noted that an operator reported a crack finding in Zone 1 that occurred on an airplane with 15,722 total flight cycles. Boeing added that previous data supported the threshold of 18,000 flight cycles, but this new finding supports the 15,000 total flight cycle threshold. Boeing stated that since FAA letter 120S14-181, dated March 26, 2014 (which extends the compliance times specified in AD 2011-01-15), and Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015 (which specifies the 18,000 flight-cycle compliance time), were released, some operators may have suspended or delayed inspections beyond 15,000 total flight cycles and up to 18,000 total flight cycles. Boeing added that a short grace period of 200 flight cycles or 90 days (which is similar to the grace period in AD 2011-01-15) should be applied for Start Printed Page 21148the initial inspection for airplanes on which the 15,000 total flight cycle threshold has been exceeded.
We agree with the commenter's request to reduce the compliance threshold for the Zone 1 inspections from 18,000 to 15,000 total flight cycles, for the reasons provided. Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, has been issued to reduce the compliance time for the Zone 1 inspections. We have changed the compliance time specified in paragraph (g)(1) of this proposed AD and added a new paragraph (h) to this proposed AD to specify the reduced compliance times.
We agree with the commenter. We have redesignated paragraph (c) of the proposed AD (in the NPRM) as (c)(1) and added a new paragraph (c)(2) to this proposed AD to state that installation of STC ST01518SE does not affect the ability to accomplish the proposed actions. Therefore, for airplanes on which STC ST01518SE is installed, a “change in product” AMOC approval request is not necessary to comply with the requirements of 14 CFR 39.17.
European Air Transport Leipzig GmbH and DHL Air Ltd. asked that we remove all duplicated data from the NPRM, and only refer to the compliance tables specified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. The commenters stated that the compliance information is contained in detail in the referenced service information, and is repeated in the NPRM without benefit of clarification. The commenters added that the stringers identified for inspection in paragraphs (g)(3)(i) and (g)(3)(ii) of the proposed AD are incorrect, and should refer to inspection Zone 3 containing stringers S-3L, S-2L, S-1, S-2R, andS-3R.
We partially agree with the commenters' request. We agree to revise this proposed AD for clarity but we do not agree to remove all of the details for the required actions in this proposed AD. The stringers identified for inspection in paragraphs (g)(3)(i) and (g)(3)(ii) of the proposed AD are correct, as specified in the referenced service information. However, paragraphs (g)(3)(i) and (g)(3)(ii) of the proposed AD (in the NPRM) should have specified between stringers S-3L to S-3R instead of “at stringers S-3L and S-3R.” Since the stringer location is clear in the service information, we have removed the reference to the stringers in paragraphs (g)(3)(i) and (g)(3)(ii) of this proposed AD. Instead, we have added a reference to the Zone 3 areas of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
Boeing and United Airlines (UA) asked that we clarify the inspection language specified in paragraphs (g)(1)(i) and (g)(1)(ii) of the proposed AD. Boeing asked that we include “Zone 1 areas” and “as applicable” in the description. UA stated that it appears that the inspections are for “Zone 1 areas.” Boeing stated that the Zone 1 areas are clearly delineated in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015.
We agree with the commenters' request for the reason provided. As stated previously, this proposed AD cites Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. We have clarified the inspection language in paragraph (g)(1) of this proposed AD. We have also clarified similar inspection language in paragraph (g)(2) of this proposed AD.
UA asked that we clarify the optional terminating action in paragraph (j)(2) of the proposed AD, to eliminate the need for a new AMOC as terminating action for the inspections after replacing the crown skin panel using a method approved in accordance with paragraph (m) of the proposed AD. UA noted that Note (c) of Table 1, Note (b) of Table 2, and Note (b) of Table 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015, stipulate that the skin replacement itself is considered terminating action to all inspections done in accordance with the referenced service information. UA added that this is based on the fact that the skin chem-mill process defect should not be present in the new skin. UA noted that this method of skin replacement is not part of the safety consideration, and should not require a new AMOC.
We agree with the commenter's request. We have clarified paragraph (k)(2) of this proposed AD (which was referred to as paragraph (j)(2) of the proposed AD (in the NPRM)) to add replacing the crown skin panel in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, or using a method approved in accordance with the procedures specified in paragraph (n) of this proposed AD (which was referred to as paragraph (m) of the proposed AD (in the NPRM)), terminates the inspections.
Boeing asked that we include the possibility that cracking may have been found during the inspections required by paragraph (g) of AD 2011-01-15 in the provisional requirements of paragraphs (g)(2) and (g)(3) of the proposed AD (in the NPRM). Boeing recommended including a reference to paragraph (g) of AD 2011-01-15 as follows: “For airplanes on which any crack is found during any inspections required by Paragraph (g)(1) of this AD or previously per AD 2011-01-15, Paragraph (g); or any repair . . . .” Boeing added that to exclude this language could lead operators to infer that it precludes previous findings from inclusion in the provisional statement.
We acknowledge the commenter's concerns. As of the effective date of the final rule following this SNPRM, AD 2011-01-15 will no longer exist since it will be superseded by the new AD. For this reason, we do not typically refer to a superseded AD in a new AD requirement. However, paragraphs (g)(2) and (g)(3) of this proposed AD do include findings from paragraph (g) of AD 2011-01-15. Paragraph (h) of AD 2011-01-15 states that a repair must be done before further flight if any crack is found. Therefore, for any crack found before the effective date of the final rule, the crack should already have been repaired. Paragraph (g)(2) of this proposed AD states “. . . or any repair is installed that covers any portion of the Zone 1 inspection area . . .” and that statement covers the crack findings in AD 2011-01-15.
In addition, paragraph (m) of this proposed AD provides credit for Zone 1 inspections required by paragraph (g)(1) of this proposed AD, if those actions were performed before the effective date of the final rule using Boeing Special Attention Service Bulletin 757-53-0097, dated November 22, 2010; Revision 1, dated January 6, 2011; or Revision 2, dated July 28, 2015. We Start Printed Page 21149have not changed this proposed AD in this regard.
Boeing and UA asked that a new paragraph (l)(3) be added to the proposed AD to provide credit for previous inspections done using previous revisions of the referenced service information to accomplish the inspections in paragraph (g)(1) of this AD. Those inspections were approved as an AMOC to AD 2011-01-15.
We do not agree with the commenter's request. It is not necessary to include credit for inspections that were done using previous revisions of the referenced service information, because credit for those inspections is already provided in paragraph (m) of this proposed AD. Therefore, we have not changed this proposed AD in this regard.
UA asked that we include credit language in this proposed AD for inspecting previously approved repairs, as specified in Note (a) of Table 1, Note (c) of Table 2, and Note (c) of Table 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. UA stated that including this credit would avoid unnecessary work stoppage and minimize future AMOC requests for repairs which meet these criteria.
We agree that operators are allowed credit for inspecting previously approved repairs, as specified in the notes in Tables 1, 2, and 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. However, we do not agree that the language in those notes should be added to this proposed AD because Parts 1, 2, and 3 of the Work Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, also include those credit notes. This proposed AD requires accomplishing the specified actions in accordance with the Accomplishment Instructions, which includes those notes in the Work Instructions; therefore, operators are given credit. We have not changed this proposed AD in this regard.
Boeing and UA asked that we clarify the inspection area in paragraphs (g)(2)(i) and (g)(2)(ii) of the proposed AD to include the Zone 2 areas, and also that we clarify the inspection area in paragraphs (g)(3)(i) and (g)(3)(ii) of the proposed AD to include the Zone 3 areas. Boeing and UA stated that the zones are identified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015.
We agree with the commenters' requests for the reason provided. As stated previously, this proposed AD cites Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. We have clarified the inspection language in paragraphs (g)(2)(i) and (g)(2)(ii), and (g)(3)(i) and (g)(3)(ii), of this proposed AD to include the Zone 2 and Zone 3 areas, respectively.
Boeing asked that we change paragraph (g)(1) of the proposed AD to clarify that the inspections should be done using the instructions specified in Part 1 or Part 2 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. Boeing stated that this clarification would avoid confusion.
We agree with the commenter's request for the reason provided. We have clarified paragraphs (g)(1), (g)(1)(i), and (g)(1)(ii) of this proposed AD to include doing the inspection as specified in Part 1 or Part 2 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
Boeing and UA asked that we change paragraph (g)(2) of the proposed AD to clarify that the Zone 2 inspections should be done using the instructions specified in Part 4 or Part 5 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. Boeing stated that those areas are clearly identified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015, and should be included for clarity.
We agree with the commenter's request for the reason provided. We have clarified paragraphs (g)(2), (g)(2)(i), and (g)(2)(ii) of this proposed AD to include doing the Zone 2 inspections as specified in Part 4 or Part 5 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
Boeing and UA asked that we change paragraph (g)(3) of the proposed AD to clarify that the Zone 3 inspections should be done using the instructions specified in Part 6 or Part 7 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. Boeing and UA stated that those areas are clearly identified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015, and should be included for clarity.
We agree with the commenters' request for the reason provided. We have clarified paragraphs (g)(3), (g)(3)(i), and (g)(3)(ii) of this proposed AD to include doing the Zone 3 inspections as specified in Part 6 or Part 7 of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. The reference to Part 6 and Part 7 also applies to the repetitive inspections.
Boeing asked that we clarify the inspection language in paragraph (j)(1) of the proposed AD to better describe the inspections required when doing the preventative modification. Boeing stated that it should specify doing high frequency eddy current open-hole inspections for cracking in existing fastener holes. Boeing noted that Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015, clearly specifies using an open-hole inspection, and added that if this inspection is not defined it would permit operators to do a surface inspection around the fasteners, which is not sufficient to ensure there is no cracking in the fastener holes.
Boeing also asked that we change the paragraph identifier at the end of paragraph (j)(1) of the proposed AD from (g) to (g)(1) since the referenced inspection is actually required by paragraph (g)(1) of the proposed AD. Boeing also asked that we change that paragraph identifier in paragraphs (l)(1) and (l)(2) of the proposed AD. Boeing stated that paragraph (g) of the proposed AD merely refers to the inspection paragraphs.
We agree with the commenter's requests for the reasons provided. We have clarified the inspection language in paragraph (k)(1) of this proposed AD (which was referred to as paragraph (j)(1) of the proposed AD (in the NPRM)) to include “. . . open-hole inspections for cracking in existing fastener holes.”
We have also changed the paragraph identifiers in paragraphs (k)(1) and (m) of this proposed AD (which were referred to as paragraphs (j)(1), (l)(1), and (l)(2) of the proposed AD (in the NPRM)) to specify paragraph (g)(1) of this proposed AD accordingly.
Boeing asked that we change paragraphs (g)(2) and (g)(3) of the proposed AD to clarify that the repair can cover “any portion” of the Zone 1 Start Printed Page 21150area, and asked that the description be changed to include those words. Boeing stated that currently the inspection area specified in those paragraphs could be interpreted as a repair that would need to cover the entire Zone 1 inspection area; however, operators typically install local repairs in areas where cracks are found.
We agree with the commenter's request for the reason provided. We have clarified paragraphs (g)(2) and (g)(3) of this proposed AD to include the words “any portion” of the Zone 1 repair area to be inspected.
Boeing asked that we change paragraphs (g)(2) and (g)(3) of the proposed AD to clarify that “any preventative modification” is actually “the optional Zone 1 preventative modification specified in paragraph (j)(1) of the NPRM.” Boeing stated that there is only one specific preventative modification specified in the referenced service information that necessitates the inspections in paragraphs (g)(2) and (g)(3) of the proposed AD.
We agree with the commenter's request for the reason provided. We have clarified paragraphs (g)(2) and (g)(3) of this proposed AD to include the language provided by the commenter.
Boeing asked that we change paragraph (k)(3) of the proposed AD to clarify that the exception covers cracking found during any inspection required by paragraph (h) or (j)(1) of the proposed AD (in the NPRM). Boeing stated repairing any crack found during the inspection before installation of the preventative modification in paragraph (h) of the proposed AD (in the NPRM) should also be an exception.
We do not agree with the commenter's request. Paragraph (j) of this proposed AD (which was referred to as paragraph (i) of the proposed AD (in the NPRM)) already specifies repairing any cracking found during any inspection required by paragraph (i) of this proposed AD (which was referred to as paragraph (h) of the proposed AD (in the NPRM)), as well as inspections required by paragraphs (g)(1), (g)(2), and (g)(3) of this proposed AD. Paragraph (k)(3) of the proposed AD (in the NPRM) was intended to address cracking found during the preventative modification specified in paragraph (j)(1) of the proposed AD (in the NPRM). For clarity in this proposed AD, we have added the corrective action for cracking found during the inspection specified in paragraph (k)(1) of this proposed AD (which was referred to as paragraph (j)(1) of the proposed AD (in the NPRM)) into paragraph (k)(1) of this proposed AD. We have also removed paragraph (k)(3) of the proposed AD (in the NPRM) from this proposed AD.
Two commenters requested that we clarify whether existing AMOCs are approved. UA asked that paragraph (m)(4) of the proposed AD (in the NPRM) be changed to clarify that repairs approved previously as AMOCs to AD 2011-01-15 require no further evaluation or approval. UA stated that operators were required to repair any finding with a repair that included an AMOC to AD 2011-01-15. UA stated that the current language in paragraph (m)(4) of the proposed AD (in the NPRM) would invalidate all such AMOCs, forcing operators to submit new requests for approval for each previously approved repair. In addition, UA asked that we include a new paragraph (l)(3) to provide credit for inspections required by paragraph (g)(1) of the proposed AD (in the NPRM) that were approved as an AMOC to AD 2011-01-15.
Boeing asked if paragraph (m)(4) of the proposed AD (in the NPRM) meant that new AMOCs are needed for all AMOCs to AD 2011-01-15. Boeing asked that credit be given for inspections required by paragraph (g)(1) of the proposed AD (in the NPRM) that were approved as an AMOC to AD 2011-01-15 in Boeing Alternative Method of Compliance Notice 757-53-0097-AMOC-01, dated March 28, 2011, and stated in FAA letter 120S-11-13, dated January 19, 2011. Boeing stated that the AMOC allowed a longer interval for the inspections that are now incorporated in Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015. Boeing also noted that Boeing Alternative Method of Compliance Notice 757-53-0097 AMOC 03, dated March 28, 2014, should be rescinded since new data shows that a 15,000 total flight cycle threshold is appropriate instead of 18,000 total flight cycles.
We agree that clarification is necessary. Although paragraph (m)(4) of the proposed AD (in the NPRM) specified that AMOCs approved for AD 2011-01-15, are not approved as AMOCs for the corresponding provisions of paragraph (g) of the proposed AD (in the NPRM); after further review we have determined those AMOCs should continue to be approved, except as of the effective date of this proposed AD, AMOCs that extend the initial compliance times specified in AD 2011-01-15 are no longer approved for the compliance time extension and instead, the compliance times required by this proposed AD must be complied with. Boeing Alternative Method of Compliance Notice 757-53-0097 AMOC 03, dated March 28, 2014, extended the initial compliance times specified in AD 2011-01-15, and as stated previously, we have received new data that does not justify the extended compliance times. We have changed paragraph (n)(4) of this proposed AD (which was referred to as paragraph (m)(4) of the proposed AD (in the NPRM)) accordingly.
Boeing asked that paragraph (m)(3) of the proposed AD (in the NPRM) be changed from “For a repair method to be approved the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane and the approval must specifically refer to this AD” to “For a repair method, modification deviation, or alteration deviation to be approved the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane and the approval must specifically refer to this AD.” Boeing stated that this approval needs to specify not only for a repair method to be approved, but also for modification and alteration deviations to be approved, they must meet type certification.
We agree that some clarification is necessary. We have clarified paragraph (n)(3) of this proposed AD (which was referred to as paragraph (m)(3) of the proposed AD (in the NPRM)) as follows: “An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.”
Boeing asked that we change the punctuation following the word “repair” in the first sentence of paragraph (m)(3) of the proposed AD (in the NPRM) from a period to a comma. Boeing noted that this is a punctuation error.
We agree with the commenter's request and have corrected the Start Printed Page 21151punctuation in paragraph (n)(3) of this proposed AD (which was referred to as paragraph (m)(3) of the proposed AD (in the NPRM)) accordingly.
A commenter, Jonathan Fortune, stated that it is imperative that any potentially catastrophic structural issues identified in any airplanes be promptly corrected. Mr. Fortune added that repair costs are greatly outweighed by the potential marketing and industry disaster that would occur if these airplanes crashed. Mr. Fortune noted that Boeing should not be able to operate these airplanes without addressing these issues. Mr. Fortune stated that he is willing to pay for increased air travel costs in order to get the sense of safety established through compliance with this regulation.
We acknowledge and appreciate the commenter's concerns. The FAA works to ensure that all unsafe conditions are addressed in a timely manner in accordance with FAA risk management policies that are designed to promote aviation safety.
This SNPRM would require accomplishing the actions specified in the service information described previously. For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-3697.
We estimate that this proposed AD affects 652 airplanes of U.S. registry.
Inspections (Zone 1) [Retained actions from AD 2011-01-15] 2 work-hour × $85 per hour = $170 per inspection cycle $0 $170 per inspection cycle $110,840 per inspection cycle.
Inspections (Zones 2 and 3) [new proposed action] Up to 4 work-hours × $85 per hour = Up to $340 per inspection cycle $0 Up to $340 per inspection cycle Up to $221,680 per inspection cycle.
Optional modification Up to 615 work-hours × $85 per hour = Up to $52,275 Up to $26,496 Up to $78,771 Up to $51,358,692.
We have received no definitive data that would enable us to provide a cost estimate for the optional replacement specified in this proposed AD.
2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2011-01-15, Amendment 39-16572 ( 76 FR 1351, January 10, 2011), and adding the following new AD.
The Boeing Company: Docket No. FAA-2016-3697; Directorate Identifier 2015-NM-143-AD.
We must receive comments by June 19, 2017.Start Printed Page 21152
This AD replaces AD 2011-01-15, Amendment 39-16572 (76 FR 1351, January 10, 2011) (“AD 2011-01-15”).
(1) This AD applies to The Boeing Company Model 757-200 and -300 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
This AD was prompted by reports of the initiation of fatigue cracking in the fuselage skin of the crown skin panel along locally thinned channels adjacent to the chem-milled steps. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin of the crown skin panel, which could result in pressure venting and consequent rapid decompression of the airplane.
Do the applicable inspections required by paragraphs (g)(1), (g)(2), and (g)(3) of this AD.
(1) For all airplanes: Within the compliance time specified in paragraph (h) of this AD, do the Zone 1 inspection specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD. Repeat the applicable Part 1 or Part 2 inspection thereafter at the applicable times specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. Accomplishing the preventative modification specified in paragraph (k)(1) of this AD or the replacement specified in paragraph (k)(2) of this AD terminates the inspections required by this paragraph.
(i) Do an external sliding probe eddy current (EC) inspection for cracking of the crown skin panel in the applicable Zone 1 areas specified in, and in accordance with, Part 1 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
(ii) Do an external spot-probe-medium-frequency EC inspection for cracking of the crown skin panel in the applicable Zone 1 areas specified in, and in accordance with Part 2 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
(2) For airplanes on which any crack is found during any inspection required by paragraph (g)(1) of this AD; or any repair is installed that covers any portion of the Zone 1 inspection area specified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016; or the optional Zone 1 preventative modification specified in paragraph (k)(1) of this AD is installed: At the applicable time specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, except as required by paragraph (l)(1) of this AD: Do the Zone 2 inspection specified in paragraph (g)(2)(i) or (g)(2)(ii) of this AD. Repeat the applicable Part 4 or Part 5 inspection thereafter at the applicable times specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. Accomplishing the replacement specified in paragraph (k)(2) of this AD terminates the inspections required by this paragraph.
(i) Do an external sliding probe EC inspection for cracking of the crown skin panel in the applicable Zone 2 areas specified in, and in accordance with, Part 4 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
(ii) Do an external spot-probe-medium-frequency EC inspection for cracking of the crown skin panel in the applicable Zone 2 areas specified in, and in accordance with, Part 5 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
(3) For airplanes on which any crack is found during any inspection required by paragraph (g)(1) of this AD; or any repair is installed that covers any portion of the Zone 1 inspection area specified in Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016; or the optional Zone 1 preventative modification specified in paragraph (k)(1) of this AD is installed: At the applicable time specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, except as required by paragraph (l)(1) of this AD, do the Zone 3 inspection specified in paragraph (g)(3)(i) or (g)(3)(ii) of this AD. Repeat the applicable Part 6 or Part 7 inspection thereafter at the applicable times specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. Accomplishing the replacement specified in paragraph (k)(2) of this AD terminates the inspections required by this paragraph.
(i) Do an external sliding probe EC inspection for cracking of the crown skin panel in the applicable Zone 3 areas specified in, and in accordance with, Part 6 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
(ii) Do an external spot-probe-medium-frequency EC inspection for cracking of the crown skin panel in the applicable Zone 3 areas, specified in, and in accordance with, Part 7 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
Within the applicable compliance times specified in paragraphs (h)(1), (h)(2), (h)(3), and (h)(4) of this AD, whichever occurs latest: Do the initial inspection required by paragraph (g)(1) of this AD.
(1) For all airplanes: Before the accumulation of 15,000 total flight cycles.
(2) For airplanes on which an external sliding probe EC inspection for Zone 1, as specified in Boeing Special Attention Service Bulletin 757-53-0097, has been done as of the effective date of this AD: Within 620 flight cycles after accomplishing the most recent external sliding probe EC inspection for Zone 1.
(3) For airplanes on which an external spot-probe-medium-frequency EC inspection for Zone 1, as specified in Boeing Special Attention Service Bulletin 757-53-0097, has been done as of the effective date of this AD: Within 200 flight cycles after accomplishing the most recent external spot-probe-medium-frequency EC inspection for Zone 1.
(4) For all airplanes: Within 200 flight cycles or 90 days after the effective date of this AD, whichever occurs first.
For airplanes on which a preventive modification has been installed as specified in Part 3 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016: At the applicable time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016; do eddy current and detailed inspections for cracking of the applicable areas of the fuselage skin of the doublers, triplers, and fillers of the preventive modification, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016. Repeat the inspection thereafter at the applicable times specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016.
If any cracking is found during any inspection required by paragraph (g)(1), (g)(2), (g)(3), or (i) of this AD, repair before further flight using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Doing the repair ends the repetitive inspections for the repaired area only.Start Printed Page 21153
(1) Accomplishing the preventative modification, including doing high frequency EC open-hole inspections for cracking in the existing fastener holes, in accordance with Part 3 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, except as required by paragraph (l)(2) of this AD, terminates the inspections required by paragraph (g)(1) of this AD, provided the preventative modification is done before further flight after accomplishing an inspection required by paragraph (g)(1) of this AD. If any cracking is found during any high frequency EC open-hole inspection, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(2) Replacing the crown skin panel between station (STA) 297 and STA 439, and stringers S-4L and S-4R, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, or using a method approved in accordance with the procedures specified in paragraph (n) of this AD, terminates the inspections required by paragraphs (g)(1), (g)(2), and (g)(3) of this AD.
(1) Where Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, specifies a compliance time “after the Revision 2 date of this service bulletin,” or “after the Revision 3 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Special Attention Service Bulletin 757-53-0097, Revision 3, dated December 2, 2016, specifies to contact Boeing for repair instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
This paragraph provides credit for Zone 1 inspections required by paragraph (g)(1) of this AD, if those actions were performed before the effective date of this AD using Boeing Special Attention Service Bulletin 757-53-0097, dated November 22, 2010 (which was incorporated by reference in AD 2011-01-15); Boeing Special Attention Service Bulletin 757-53-0097, Revision 1, dated January 6, 2011; or Boeing Special Attention Service Bulletin 757-53-0097, Revision 2, dated July 28, 2015.
(4) AMOCs approved for AD 2011-01-15 are approved as AMOCs for the corresponding provisions of paragraph (g) of this AD; except, as of the effective date of this AD, AMOCs that extend the initial compliance times specified in AD 2011-01-15 are no longer approved for the compliance time extension and the compliance times required by this AD must be complied with.
(5) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (n)(5)(i) and (n)(5)(ii) apply.
[FR Doc. 2017-07938 Filed 5-4-17; 8:45 am]