Airworthiness Directives; Boeing Model 727 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 727 airplanes. This AD requires repetitive inspections for cracks of the body skin, doubler, and bear strap at the forward edge of the upper and lower hinge cutouts of the forward entry door, related investigative actions, and corrective action if necessary. This AD also requires a preventive modification. This AD results from reports of skin and bear strap cracks at hinge cutouts of the forward entry door. We are issuing this AD to detect and correct cracks in the skin, doubler, and bear strap at the hinge cutouts of the forward entry door, which could result in rapid decompression of the airplane.

DATES:

This AD becomes effective July 16, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of July 16, 2007.

ADDRESSES:

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6577; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 727 airplanes. That NPRM was published in the Federal Register on June 14, 2005 (70 FR 34405). That NPRM proposed to require repetitive inspections for cracks of the body skin, doubler, and bear strap at the forward edge of the upper and lower hinge cutouts of the forward entry door, related investigative actions, and corrective action if necessary. That NPRM also proposed to require a preventive modification.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Request To Refer to Latest Revision of Service Bulletin

Boeing requests that we refer to Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006, in the NPRM (Revision 2, dated October 30, 2003, was the latest version of the service bulletin at the time the NPRM was issued and was referred to as the appropriate source of service information for doing the actions specified in the NPRM). Boeing states that Revision 3 of the service bulletin clarifies details described in the NPRM but does not increase the scope of the final rule. Boeing concludes that use of Revision 3 would necessitate fewer clarifying comments.

We have reviewed Revision 3 of the service bulletin and concur with Boeing's assessment. Revision 3 provides the following information:

• Corrects and clarifies fastener symbols in Figures 2, 4, 5, and 6, and revises the fastener code “F” to “D” where applicable.
• Changes fastener part numbers and quantities in the Materials section to agree with data specified in Figures 2, 4, 5, and 6.
• Adds more data to Paragraph 1.E., “Compliance,” and Table 1 in Appendix A to give more detail about airplane conditions, thresholds, and subsequent work.
• Clarifies inspection and repeat inspection data in paragraph 3.B. of the Work Instructions.

We have revised the final rule to refer to Revision 3 of the service bulletin as the appropriate source of service information for doing the required actions. We have also revised the descriptions of the actions specified in paragraphs (h) and (i) of the final rule to parallel the new descriptions in Revision 3 of the service bulletin. We have also clarified the inspection area specified in paragraph (g) of the final rule.

We also removed paragraph (n) of the NPRM from the final rule (and re-identified subsequent paragraphs accordingly) because the information specified in paragraph (n) of the NPRM is now included in Revision 3 of the service bulletin.

We have also added new paragraph (o) to the final rule to allow credit for actions done in accordance with Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003.

Request To Revise Grace Period in Paragraph (j) of the NPRM

Boeing requests that we revise the grace period specified in paragraph (j) of the NPRM for the preventive modification from “within 3,000 flight cycles after the effective date of this AD” to “within the earlier of 4 years or 7,200 flight cycles after the effective date of this AD.” Boeing states the new grace period would match the grace period specified in AD 90-06-09, amendment 39-6488 (55 FR 8370, March 7, 1990), which mandates airplane modification requirements. Boeing notes that the “preventive modification requirement is based on Structures Task Group (STG) recommendations found in Boeing Document D6-54860 per AD 90-06-09.” Boeing states that the 4-year grace period specified in AD 90-06-09 allows operators to schedule airplane modifications during major maintenance checks.

We agree to revise the grace period. AD 90-06-09 and this final rule require certain airplane modifications at 60,000 flight cycles. Coordinating the grace period allows operators to schedule the airplane modifications at the same time. We have determined that extending the grace period, as recommended by the manufacturer, will not adversely affect safety. We have revised the grace period in paragraph (j) of this final rule from “within 3,000 flight cycles after the effective date of this AD” to “within 48 months or 7,200 flight cycles, after the effective date of this AD, whichever occurs earlier.”

Request to Revise References to Fillers and Shims

Boeing requests that we revise paragraph (h)(1) of the NPRM from “if the filler or shim is missing” to “if the filler is not present” and that we revise paragraph (h)(2) of the NPRM from “if the filler and shim are not missing” to “if the filler is present.” Boeing also requests that we make these same changes in two paragraphs of the Relevant Service Information section of the NPRM. Boeing states that the inspection is made to determine if the filler is present or not, which is easier to understand than determining if it is missing or not missing. Boeing also states that references to a shim may be confusing because the service bulletin specifies that a filler is what is to be installed. Boeing notes that local shims may have been installed to allow local fit-up; however, a filler is considerably larger and is required for the quality of the general repair accomplishment.

We agree because of the reasons stated by the commenter. We have revised paragraphs (h)(1) and (h)(2) of the final rule accordingly. We have also revised paragraph (h) of the final rule to remove the reference to the shim. We have also added a clarification in paragraph (h) that airplanes on which the actions specified in Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991, have been done do not need the inspection to determine if a filler was installed.

However, because the Relevant Service Information section of the NPRM is not restated in the final rule, we have not changed the final rule in that regard.

Request To Specify Modification Installation

Boeing requests that we revise paragraphs (h)(1)(i) and (h)(2)(i) of the NPRM to include “install modification” in the description of the action; i.e., “* * * oversize the fastener holes and install modification in accordance with * * *.” Boeing states that it is clearer to complete the information to include the modification installation beyond just inspecting and oversizing the fastener holes.

We partially agree with the commenter. We agree that adding installation information will communicate more completely the requirements of the final rule. However, instead of adding “install modification” to the description in paragraphs (h)(1)(i) and (h)(2)(i) of the final rule, we have added the phrase “and re-install the repair or preventive modification” to those paragraphs to clarify that it could be either a repair or modification that is being re-installed.

Request To Clarify Reason for Modification

Boeing requests that we revise the “FAA's Determination and Requirements of the Proposed AD” section of the NPRM to clarify the reason we are requiring the modification. Boeing suggests that the statement that the preventive modification will be required should be revised to include the following: “[The] preventive modification requirement is based on Structures Task Group (STG) recommendations found in Boeing Document D6-54860 per AD 90-06-09.”

We agree with the commenter that its statement provides a rationale for the preventive modification requirements of the final rule. However, because the “FAA's Determination and Requirements of the Proposed AD” section of the NPRM is not restated in the final rule, we have not changed the final rule in this regard.

Request To Revise Paragraphs (o) and (p) of the NPRM

Boeing requests that paragraph (o) of the NPRM be revised to more clearly state the actions or integrate the thresholds into paragraph (p) of the NPRM. Boeing states that paragraphs (o)(1) and (o)(2) of the NPRM are incomplete and that paragraph (o)(1) of the NPRM includes a sentence that is more of a clarification that belongs in paragraph (o) of the NPRM.

We agree that although paragraphs (o) and (p) of the NPRM are functional, the paragraphs could be revised for clarity. The initial and repetitive inspections that are specified in paragraphs (o) and (p) of the final rule are to be done after a repair or modification has been done.

For clarity, we have added the repetitive inspections to paragraph (i) of the final rule. Paragraph (i) of the final rule specifies to do the initial inspections after a repair or modification is accomplished. As a result of these changes, we have removed paragraphs (o) and (p) of the NPRM from the final rule (and re-identified subsequent paragraphs accordingly).

We have also revised paragraph (p)(4) of the final rule (which we referred to as paragraph (r)(2) in the NPRM) to refer to paragraph (i) of the final rule as the method of compliance to paragraph (g) of AD 98-11-03 R1, amendment 39-10983.

Clarification of Unsafe Condition Statement

We have revised the unsafe condition statement in the summary and in paragraph (d) of this final rule. In addition to detecting and correcting cracks in the skin and bear strap at the hinge cutouts of the forward entry door, this final rule is also issued to detect and correct cracks in the doubler. We have revised the unsafe condition statement accordingly. The actions specified in the NPRM were adequate; however, the unsafe condition did not specify all the areas that were proposed to be inspected. We are not expanding the scope in the final rule.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

We have revised paragraph (p) of this final rule to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

We have also revised paragraph (p) of this final rule to allow any crack in the subject area to be repaired according to data that conform to the airplane's type certificate and that are approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make such findings. We have simplified paragraph (m)(2) of this final rule by referring to paragraph (p) of this final rule for repair methods.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 1,015 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD.

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); and

(3) 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 a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

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

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

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

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

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2007-12-14 Boeing: Amendment 39-15092. Docket No. FAA-2005-21434; Directorate Identifier 2004-NM-75-AD.

Effective Date

(a) This AD becomes effective July 16, 2007.

Affected ADs

(b) None

Applicability

(c) This AD applies to all Boeing Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes, certificated in any category.

Unsafe Condition

(d) This AD was prompted by reports of skin and bear strap cracks at hinge cutouts of the forward entry door. We are issuing this AD to detect and correct cracks in the skin, doubler, and bear strap at the hinge cutouts of the forward entry door, which could result in rapid decompression of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Service Bulletin Reference

(f) The term “the service bulletin,” as used in this AD, means Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006. Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement.

Initial and Repetitive Inspections for Airplanes on Which No Actions Have Been Done

(g) For airplanes on which no repair or preventive modification has been done before the effective date of this AD in accordance with Boeing Service Bulletin 727-53-0198, dated January 11, 1990; Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991; Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003; or Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006: Within 3,000 flight cycles after the effective date of this AD, do detailed and high frequency eddy current (HFEC) inspections for cracks of the skin, doubler, and bear strap at the upper and lower hinge cutout of the forward entry door in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006.

(1) If no crack is found, before further flight, apply finishes in accordance with the Accomplishment Instructions of the service bulletin and repeat the inspections required by paragraph (g) of this AD thereafter at intervals not to exceed 3,000 flight cycles, until the preventive modification required by paragraph (j) of this AD or a repair required by paragraph (m) of this AD is done.

(2) If any crack is found, before further flight, do the repair specified in paragraph (m) of this AD.

Inspections for Airplanes on Which Certain Actions Have Been Done

(h) For airplanes on which any repair or preventive modification has been done before the effective date of this AD in accordance with Boeing Service Bulletin 727-53-0198, dated January 11, 1990; or in accordance with Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991, and on which the existing fastener holes were not HFEC inspected and oversized by 1/16 of an inch in accordance with step 3.B.9. of the Accomplishment Instructions of Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003, or Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006: Within 12,000 flight cycles after the repair or preventive modification was done or within 3,000 flight cycles after the effective date of this AD, whichever is later, do a detailed inspection to determine if a filler was installed below the S-10 lap joint common to the upper hinge cutout, an internal HFEC inspection for cracks of the bear strap, and an external detailed inspection for cracks of the repair or preventive modification and its periphery, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006. Airplanes on which the actions specified in Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991, have been done do not need the inspection to determine if a filler was installed.

(1) For airplanes on which the filler is not present: Before further flight, remove the external doubler, do detailed and HFEC inspections for cracks at the hinge cutout areas specified in Figure 1 of the service bulletin, and do an HFEC inspection of the pre-existing fastener holes for cracks, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006.

(i) If no crack is found, before further flight, oversize the fastener holes and re-install the repair or preventive modification in accordance with the Accomplishment Instructions of the service bulletin.

(ii) If any crack is found, before further flight, do the repair specified in paragraph (m) of this AD.

(2) For airplanes on which the filler is present and for airplanes on which the actions specified in Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991, have been done: Before further flight, do an HFEC inspection of the pre-existing fastener holes for cracks in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006.

(i) If no crack is found, before further flight, oversize the fastener holes and, as applicable, re-install the repair or preventive modification, in accordance with the Accomplishment Instructions of the service bulletin.

(ii) If any crack is found, before further flight, do the repair specified in paragraph (m) of this AD.

Inspections for Airplanes On Which a Repair/Modification Has Been Done

(i) For airplanes identified in paragraphs (i)(1), (i)(2), and (i)(3) of this AD: Within 40,000 flight cycles after the original repair or preventive modification was done or within 3,000 flight cycles after the effective date of this AD, whichever is later, do an internal HFEC inspection of the bear strap and an external detailed inspection for cracks of the repair or preventive modification and its periphery in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006. Repeat the HFEC inspection for cracks of the bear strap thereafter at intervals not to exceed 20,000 flight cycles. Repeat the detailed inspection for cracks of any repair and preventive modification and its periphery thereafter at intervals not to exceed 3,000 flight cycles. If any crack is found, before further flight, do the repair specified in paragraph (m) of this AD.

(1) Airplanes on which any repair or preventive modification has been done before the effective date of this AD in accordance with Boeing Service Bulletin 727-53-0198, dated January 11, 1990; or Revision 1, dated July 25, 1991. If a repair/preventative modification has been done in accordance with the original issue or Revision 1 of Boeing Service Bulletin 727-53-0198 and a repair/preventative modification has been done in accordance with Revision 2 of Boeing Alert Service Bulletin 727-53A0198 or Revision 3 of Boeing Service Bulletin 727-53A0198, the flight cycles must be counted from the first repair/preventative modification.

(2) Airplanes on which any repair or preventive modification has been done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003.

(3) Airplanes on which any repair or preventive modification has been done in accordance with Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006.

Preventive Modification

(j) At the later of the times specified in paragraphs (j)(1) and (j)(2) of this AD: Do the preventive modification (including HFEC inspection) in accordance with the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006. Doing the preventive modification terminates the repetitive inspections required by paragraph (g)(1) of this AD.

(1) Before the accumulation of 60,000 total flight cycles.

(2) Within 48 months or 7,200 flight cycles, after the effective date of this AD, whichever occurs earlier.

Note 1:

Repairs or preventive modifications that were done using Boeing Service Bulletin 727-53-0198, dated January 11, 1990; or Revision 1, dated July 25, 1991; are not considered acceptable for complying with the requirements of paragraph (j) of this AD.

(k) In lieu of the preventive modification required by paragraph (j) of this AD, doing the applicable repair specified in paragraph (m) of this AD is acceptable.

(l) In lieu of the preventive modification required by paragraph (j) of this AD, doing the actions specified in paragraph (h) or (i) of this AD is acceptable for the airplanes identified in those paragraphs.

Repair

(m) If any crack is found during any inspection, preventive modification, or repair required by this AD, before further flight, do the applicable repair (including HFEC inspection) specified in paragraph (m)(1) or (m)(2) of this AD, as applicable. Doing the repair terminates the repetitive inspections required by paragraph (g)(1) of this AD. Doing the repair is acceptable for compliance with the requirements of paragraph (j) of this AD provided the repair is done within the time specified in that paragraph.

(1) If the crack does not exceed the limits described in the service bulletin, repair the crack in accordance with the applicable procedures in the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006.

(2) If the crack exceeds the limits described in Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006, and the service bulletin specifies to contact Boeing, or if the service bulletin specifies to repair before further flight and contact Boeing: Repair the crack using a method approved in accordance with the procedures specified in paragraph (p) of this AD.

No Requirement To Contact Boeing

(n) Although paragraphs 3.B.9. and 3.B.10. of the Accomplishment Instructions of Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006, specify to contact Boeing after repairing cracks, this AD does not include that requirement.

Actions Accomplished According to Previous Issue of Service Bulletin

(o) Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003, are considered acceptable for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance (AMOCs)

(p)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(4) The inspections specified in paragraph (i) of this AD are approved as a method of compliance (MOC) to paragraph (g) of AD 98-11-03 R1, amendment 39-10983, for the inspections of Structurally Significant Items (SSI) F-13A and F-14A of Supplemental Structural Inspection Document (SSID), D6-48040-1, affected by the repair or modification. The MOC applies only to the areas inspected in accordance with the service bulletin. All provisions of AD 98-11-03 R1 that are not specifically referenced in paragraphs (p)(4) and (p)(5) of this AD remain fully applicable and must be complied with.

(5) For airplanes on which no repair or preventive modification has been done in accordance with Boeing Service Bulletin 727-53-0198, dated January 11, 1990; Boeing Service Bulletin 727-53-0198, Revision 1, dated July 25, 1991; Boeing Alert Service Bulletin 727-53A0198, Revision 2, dated October 30, 2003; or Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006: The inspections and actions specified in paragraph (g) of this AD are approved as a MOC to paragraph (c) of AD 98-11-03 R1 for the inspections of SSI F-13A and F-14A of SSID, D6-48040-1. This MOC applies only to the areas inspected in accordance with the service bulletin. All other provisions of AD 98-11-03 R1 that are not specifically referenced in paragraphs (p)(4) and (p)(5) of this AD remain fully applicable and must be complied with.

Material Incorporated by Reference

(q) You must use Boeing Service Bulletin 727-53A0198, Revision 3, dated October 2, 2006, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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 .