E8-1989. Airworthiness Directives; McDonnell Douglas Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 Airplanes; Model DC-8-51, DC-8-52, DC-8-53, and DC-8-55 Airplanes; Model DC-8F-54 and DC-8F-55 Airplanes; ...

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to McDonnell Douglas Model DC-8 airplanes. The existing AD currently requires, among other things, revision of an existing program of structural inspections. This proposed AD would require implementation of a program of structural inspections of baseline structure to detect and correct fatigue cracking in order to ensure the continued airworthiness of these airplanes as they approach the manufacturer's original fatigue design life goal. This proposed AD results from a significant number of these airplanes approaching or exceeding the design service goal on which the initial type certification approval was predicated. We are proposing this AD to detect and correct fatigue cracking that could compromise the structural integrity of these airplanes.

DATES:

We must receive comments on this proposed AD by March 21, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; 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 (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Jon Mowery, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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-2008-0123; Directorate Identifier 2007-NM-056-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 will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On January 11, 1993, we issued AD 93-01-15, amendment 39-8469 (58 FR 5576, January 22, 1993), for McDonnell Douglas Model DC-8 airplanes. That AD requires structural inspections to detect fatigue cracking, reporting of the inspection results, and repair, as necessary, to ensure continued airworthiness as these airplanes approach the manufacturer's original fatigue design life goal. That AD resulted from new data submitted by the manufacturer indicating that additional inspections and an expanded sample size are necessary to increase the confidence level of the statistical program to ensure timely detection of cracks in the principal structural elements (PSEs). We issued that AD to prevent fatigue cracking, which could result in a compromise of the structural integrity of these airplanes.

Supplemental Inspection Documents (SIDs) ADs

In the early 1980s, as part of our continuing work to maintain the structural integrity of older transport category airplanes, we concluded that the incidence of fatigue cracking may increase as these airplanes reach or exceed their design service goal (DSG). A significant number of these airplanes were approaching or had exceeded the DSG on which the initial type certification approval was predicated. In light of this, and as a result of increased utilization, longer operational lives, and the high levels of safety expected of the currently operated transport category airplanes, we determined that a supplemental structural inspection program (SSIP) was necessary to ensure a high level of structural integrity for all airplanes in the transport fleet.

Issuance of Advisory Circular (AC)

As a follow-on from that determination, we issued AC No. 91-56, “Supplemental Structural Inspection Program for Large Transport Category Airplanes,” dated May 6, 1981. That AC provides guidance material to manufacturers and operators for use in developing a continuing structural integrity program to ensure safe operation of older airplanes throughout their operational lives. This guidance material applies to transport airplanes that were certified under the fail-safe requirements of part 4b (“Airplane Airworthiness, Transport Categories”) of the Civil Air Regulations of the Federal Aviation Regulations (FAR) (14 CFR part 25), and that have a maximum gross weight greater than 75,000 pounds. The procedures set forth in that AC are applicable to transport category airplanes operated under subpart D (“Special Flight Operations”) of part 91 of the FAR (14 CFR part 91); part 121 (“Operating Requirements: Domestic, Flag, and Supplemental Operations”); part 125 (“Certification and Operations: Airplanes having a Seating Capacity of 20 or More Passengers or a Maximum Payload of 6,000 Pounds or More”); and part 135 (“Operating Requirements: Commuter and On-Demand Operations”) of the FAR (14 CFR parts 121, 125, and 135). The objective of the SSIP was to establish inspection programs to ensure timely detection of fatigue cracking.

Aging Aircraft Safety Act (AASA)

In October 1991, Congress enacted Title IV of Public Law 102-143, the AASA of 1991, to address aging aircraft concerns. That Act instructed the FAA administrator to prescribe regulations that will ensure the continuing airworthiness of aging aircraft.

FAA Responses To AASA

On January 25, 2005, as one of the responses to the AASA, we issued the Aging Airplane Safety; Final Rule (AASFR) (70 FR 5518, February 2, 2005). The AASFR applies to certain transport category, turbine powered airplanes with a type certificate issued after January 1, 1958 (including the airplanes that would be subject to this proposed AD), that are operated under 14 CFR parts 121 or 129, with the exception of airplanes operated within the State of Alaska. Sections 121.370a and 129.16 of the AASFR require the maintenance programs of those airplanes to include damage tolerance-based inspections and procedures for structure that is susceptible to fatigue cracking that could contribute to a catastrophic failure. The inspections and procedures must take into account the adverse affects that RAMs may have on fatigue cracking and the inspection of the structure. The procedures are to be established and incorporated before December 20, 2010. Compliance with this proposed AD also would be compliance with some aspects of the AASFR.

Relevant Service Information

We have reviewed Boeing Report No. L26-011, “DC-8 All Series Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005 (hereafter “Revision 6”). The purpose of Revision 6 is to define the mandatory inspection requirements for the PSEs and to provide specific non-destructive inspection (NDI) techniques and procedures for each PSE. Revision 6 also revises the maintenance program by removing provisions for the sampling inspection program. However, Revision 6 retains the program goal to inspect airplanes in advance of a certain threshold for the possibility of increasing that threshold and using service history to justify delaying inspections on the younger portion of the fleet. As with previous revisions, Revision 6 provides credit for inspections previously accomplished within the required intervals. Revision 6 provides a description of PSEs, NDI locations, planning and reporting procedures, and certain criteria upon which the supplemental inspection program is based.

We also have reviewed McDonnell Douglas Report No. L26-011, “DC-8 Supplemental Inspection Document (SID),” Volume II, Revision 8, dated January 2005. This document describes specific non-destructive testing inspections of the SID, and has been approved as an acceptable alternative method of compliance with corresponding paragraphs of AD 93-01-15.

Accomplishing the actions specified in the service information described above is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. This proposed AD would retain certain requirements of AD 93-01-15. This proposed AD also would require revision of the FAA-approved maintenance program. This proposed AD would require implementation of a structural inspection program of baseline structure to detect and correct fatigue cracking in order to ensure the continued airworthiness of airplanes as they approach the manufacturer's original fatigue design life goal. For the purposes of this proposed AD, a PSE is defined as an element that contributes significantly to the carrying of flight, ground or pressurization loads, and the integrity of that element is essential in maintaining the overall structural integrity of the airplane.

The following paragraphs summarize certain specific actions in this proposed AD:

Paragraph (h) of the proposed AD would require a revision of the maintenance inspection program that provides for inspection(s) of the PSE in accordance with Boeing Report No. L26-011, “DC-8 Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005. PSEs are also defined and specified in the SID.

Paragraph (i) of the proposed AD would specify that the SID be implemented on a PSE-by-PSE basis before structure exceeds its 75% fatigue life threshold (3/4N_TH) and its full fatigue life threshold (N_TH). The threshold value is defined as the life of the structure measured in total landings, when the probability of failure reaches one in a billion. The DC-8 SID program is not a sampling program. Airplanes would be inspected once before reaching both PSE thresholds (once by 3/4N_TH and once by N_TH). In order for the inspection to have value, no PSE would be inspected before half of the fatigue life threshold, 1/2N_TH. The additional 3/4N_TH threshold aids in advancing the threshold for some PSEs as explained in Section 4 of Volume I of the SID. Inspection of each PSE should be done in accordance with the NDI procedures set forth in Volume II of the SID.

For airplanes past the threshold N_TH, the proposed AD would require that the PSE be inspected at repetitive intervals not to exceed ΔNDI/2 as specified in Section 4 of Volume I of the SID per the NDI procedure, which is specified in Volume II of the SID. The definition of ΔNDI/2 is half of the life for a crack to grow from a given NDI detectable crack size to instability.

Paragraph (i) of this proposed AD also would require, for airplanes that have exceeded the N_TH, that each PSE be inspected within 18 months after the effective date of this AD. The entire PSE must be inspected regardless of whether or not it has been repaired, altered, or modified.

Paragraph (j) of this proposed AD would require that, if any PSE is repaired, altered, or modified, it must be considered a “discrepant finding.” A discrepant PSE indicates that it could not be completely inspected because the NDI procedure could not be accomplished due to differences on the airplane from the NDI reference standard (i.e., RAMs). For any discrepancy (e.g., a PSE cannot be inspected as specified in Volume II of the SID or does not match rework, repair, or modification description in Volume I of the SID), this proposed AD would require that the discrepancy be inspected in accordance with a method approved by the FAA.

Paragraph (k) of this proposed AD would require that all negative or positive findings of the inspection done in paragraph (i) of the AD be reported to Boeing at the times specified, and per instructions contained in Section 4 of Volume I of the SID.

Paragraph (l) of this proposed AD would require that any cracked structure detected during any inspection required by paragraph (i) of this proposed AD be repaired before further flight. Additionally, paragraph (l) of this AD would require accomplishment of the actions as specified in paragraphs (l)(1), (l)(2), and (l)(3) of this proposed AD, at the times specified below.

1. Within 18 months after repair, accomplish a damage tolerance assessment (DTA) that defines the threshold for inspection and submit the assessment for approval to the Manager, Los Angeles Aircraft Certification Office (ACO), FAA.

2. Before reaching 75% of the threshold, submit the inspection methods and repetitive inspections intervals for the repair for approval by the Manager of the Los Angeles ACO.

3. Before the threshold, the inspection method and repetitive inspection intervals are to be incorporated into the FAA-approved structural maintenance or inspection program for the airplane.

For the purposes of this proposed AD, the FAA anticipates that submissions of the DTA of the repair, if acceptable, should be approved within six months after submission.

Paragraph (m) of this proposed AD specifies the requirements of the inspection program for transferred airplanes. Before any airplane that is subject to this proposed AD can be added to an air carrier's operations specifications, a program for the accomplishment of the inspections required by this proposed AD must be established. Paragraph (m) of the proposed AD would require accomplishment of the following:

1. For airplanes that have been inspected per this proposed AD: The inspection of each PSE must be done by the new operator per the previous operator's schedule and inspection method, or per the new operator's schedule and inspection method, at whichever time would result in the earlier accomplishment date for that PSE inspection. The compliance time for accomplishment of this inspection must be measured from the last inspection done by the previous operator. After each inspection has been done once, each subsequent inspection must be done per the new operator's schedule and inspection method.

2. For airplanes that have not been inspected per this proposed AD: The inspection of each PSE must be done either before adding the airplane to the air carrier's operations specification, or per a schedule and an inspection method approved by the FAA. After each inspection has been performed once, each subsequent inspection must be done per the new operator's schedule.

Accomplishment of these actions will ensure that: (1) An Operator's newly acquired airplanes comply with its SSIP before being operated; and (2) frequently transferred airplanes are not permitted to operate without accomplishment of the inspections defined in the SID.

Paragraph (n) of this proposed AD specifies that repairs and inspection/replacement programs done before the effective date in accordance with McDonnell Douglas Report No. MDC 91K0262, “DC-8 Aging Aircraft Repair Assessment Program Document,” Revision 1, dated October 2000; are acceptable for compliance with the requirements of paragraphs (g) and (l) of this proposed AD.

Differences Between the Proposed AD and the SID

The SID specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Change to Existing AD

This proposed AD would retain all requirements of AD 93-01-15. Since AD 93-01-15 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:

Revised Paragraph Identifiers

Requirement in AD 93-01-15	Corresponding requirement in this proposed AD
paragraph (b)	paragraph (f).
paragraph (c)	paragraph (g).

Costs of Compliance

There are about 194 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

 Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per operator	Number of U.S.-registered airplanes	Fleet cost
Revision of maintenance inspection program (required by AD 93-01-15)	544 per operator (17 U.S. operators)	$80	$43,520	131	$739,840
Revision of maintenance program and inspections (new proposed actions)	250 per operator (17 U.S. operators)	80	20,000	131	340,000

The number of inspection work hours, as indicated above, is presented as if the accomplishment of the actions in this proposed AD is to be conducted as “stand alone” actions. However, in actual practice, these actions for the most part will be done coincidentally or in combination with normally scheduled airplane inspections and other maintenance program tasks. Therefore, the actual number of necessary additional inspection work hours will be minimal in many instances. Additionally, any costs associated with special airplane scheduling will be minimal.

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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 proposed 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
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-8469 (58 FR 5576, January 22, 1993) and adding the following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2008-0123; Directorate Identifier 2007-NM-056-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by March 21, 2008.

Affected ADs

(b) This AD supersedes AD 93-01-15.

Applicability

(c) This AD applies to all McDonnell Douglas airplanes identified in Table 1 of this AD, certificated in any category.

Model

(1) DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 airplanes.

(2) DC-8-51, DC-8-52, DC-8-53, and DC-8-55 airplanes.

(3) DC-8F-54 and DC-8F-55 airplanes.

(4) DC-8-61, DC-8-62, and DC-8-63 airplanes.

(5) DC-8-61F, DC-8-62F, and DC-8-63F airplanes.

(6) DC-8-71, DC-8-72, and DC-8-73 airplanes.

(7) DC-8-71F, DC-8-72F, and DC-8-73F airplanes.

Unsafe Condition

(d) This AD results from a significant number of these airplanes approaching or exceeding the design service goal on which the initial type certification approval was predicated. We are issuing this AD to detect and correct fatigue cracking that could compromise the structural integrity of these airplanes.

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.

Certain Requirements of AD 93-01-15

Revise the FAA-Approved Maintenance Inspection Program

(f) Within 6 months after February 26, 1993 (the effective date of AD 93-01-15), incorporate a revision of the FAA-approved maintenance inspection program that provides no less than the required inspection of the Principal Structural Elements (PSE's) defined in Sections 2 and 3 of Volume I of McDonnell Douglas Report No. L26-011, “DC-8 Supplemental Inspection Document (SID),” dated March 1991, in accordance with Section 2 of Volume III-91, dated April 1991, of that document. The non-destructive inspection techniques set forth in Sections 2 and 3 of Volume II, dated March 1991, of that SID provide acceptable methods for accomplishing the inspections required by this AD. All inspection results, negative or positive, must be reported to McDonnell Douglas, in accordance with the instructions of Section 2 of Volume III-91 of the SID. Information collection requirements contained in this regulation have been approved by the OMB under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

Corrective Action

(g) Cracked structure detected during the inspections required by paragraph (f) of this AD must be repaired before further flight, in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.

New Requirements of This AD

Revision of the Maintenance Inspection Program

(h) Within 12 months after the effective date of this AD, incorporate a revision of the FAA-approved maintenance inspection program that provides for inspection(s) of the PSEs, in accordance with Boeing Report No. L26-011, “DC-8 All Series Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005. Incorporation of this revision ends the requirements of paragraphs (f) and (g) of this AD.

Non-Destructive Inspections (NDIs)

(i) For all PSEs listed in Section 2 of Boeing Report No. L26-011, “DC-8 All Series Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005, perform an NDI for fatigue cracking of each PSE, in accordance with the NDI procedures specified in Section 2 of McDonnell Douglas Report No. L26-011, “DC-8 Supplemental Inspection Document (SID),” Volume II, Revision 8, dated January 2005, at the times specified in paragraph (i)(1), (i)(2), or (i)(3) of this AD, as applicable.

(1) For airplanes that have less than three quarters of the fatigue life threshold (3/4N_TH) as of the effective date of this AD: Perform the NDI for fatigue cracking at the times specified in paragraphs (i)(1)(i) and (i)(1)(ii) of this AD. After reaching the threshold (N_TH), repeat the inspection for that PSE at intervals not to exceed ΔNDI/2.

(i) Perform an initial NDI no earlier than one-half of the threshold (1/2N_TH) but before reaching three-quarters of the threshold (3/4N_TH), or within 60 months after the effective date of this AD, whichever occurs later.

(ii) Repeat the NDI no earlier than 3/4N_TH but before reaching the threshold (N_TH), or within 18 months after the inspection required by paragraph (i)(1)(i) of this AD, whichever occurs later.

Note 1:

The DC-8 SID and this AD refer to the repetitive inspection interval as ΔNDI/2. However, the headings of the tables in Section 4 of Volume I of the DC-8 SID refer to the repetitive inspection interval of NDI/2. The values listed under NDI/2 in the tables in Section 4 of Volume I of the DC-8 SID are the repetitive inspection intervals, ΔNDI/2.

(2) For airplanes that have reached or exceeded three-quarters of the fatigue life threshold (3/4N_TH), but less than the threshold (N_TH), as of the effective date of this AD: Perform an NDI before reaching the threshold (N_TH), or within 18 months after the effective date of this AD, whichever occurs later. Thereafter, after passing the threshold (N_TH), repeat the inspection for that PSE at intervals not to exceed ΔNDI/2.

(3) For airplanes that have reached or exceeded the fatigue life threshold (N_TH) as of the effective date of this AD: Perform an NDI within 18 months after the effective date of this AD. Thereafter, repeat the inspection for that PSE at intervals not to exceed ΔNDI/2.

Discrepant Findings

(j) If any discrepancy (e.g., differences on the airplane from the NDI reference standard, such as PSEs that cannot be inspected as specified in McDonnell Douglas Report No. L26-011, “DC-8 Supplemental Inspection Document (SID),” Volume II, Revision 8, dated January 2005, or do not match rework, repair, or modification descriptions in Boeing Report No. L26-011, “DC-8 All Series Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005) is detected during any inspection required by paragraph (i) of this AD, do the action specified in paragraph (j)(1) or (j)(2) of this AD, as applicable.

(1) If a discrepancy is detected during any inspection done before 3/4N_TH or N_TH: The area of the PSE affected by the discrepancy must be inspected before N_TH or within 18 months after the discovery of the discrepancy, whichever occurs later, in accordance with a method approved by the Manager, Los Angeles ACO.

(2) If a discrepancy is detected during any inspection done after N_TH: The area of the PSE affected by the discrepancy must be inspected before the accumulation of an additional ΔNDI/2 or within 18 months after the discovery of the discrepancy, whichever occurs later, in accordance with a method approved by the Manager, Los Angeles ACO.

Reporting Requirements

(k) All negative or positive findings of the inspections done in accordance with paragraph (i) of this AD must be reported to Boeing at the times specified in, and in accordance with, the instructions contained in Section 4 of Boeing Report No. L26-011, “DC-8 All Series Supplemental Inspection Document (SID),” Volume I, Revision 6, dated July 2005. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

Corrective Actions

(l) Any cracked structure of a PSE detected during any inspection required by paragraph (i) of this AD must be repaired before further flight using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Accomplish the actions described in paragraphs (l)(1), (l)(2), and (l)(3) of this AD, at the times specified.

(1) Within 18 months after repair, do a damage tolerance assessment (DTA) that defines the threshold for inspection of the repair and submit the assessment for approval.

(2) Before reaching 75% of the repair threshold as determined in paragraph (l)(1) of this AD, submit the inspection methods and repetitive inspection intervals for the repair for approval.

(3) Before the repair threshold, as determined in paragraph (l)(1) of this AD, incorporate the inspection method and repetitive inspection intervals into the FAA-approved structural maintenance or inspection program for the airplane.

Note 2:

For the purposes of this AD, we anticipate that submissions of the DTA of the repair, if acceptable, should be approved within 6 months after submission.

Note 3:

FAA Order 8110.54, “Instructions for Continued Airworthiness,” dated July 1, 2005, provides additional guidance about the approval of repairs to PSEs.

Inspection for Transferred Airplanes

(m) Before any airplane that has exceeded the fatigue life threshold (N_TH) can be added to an air carrier's operations specifications, a program for the accomplishment of the inspections required by this AD must be established as specified in paragraph (m)(1) or (m)(2) of this AD, as applicable.

(1) For airplanes that have been inspected in accordance with this AD: The inspection of each PSE must be done by the new operator in accordance with the previous operator's schedule and inspection method, or the new operator's schedule and inspection method, at whichever time would result in the earlier accomplishment date for that PSE inspection. The compliance time for accomplishing this inspection must be measured from the last inspection done by the previous operator. After each inspection has been done once, each subsequent inspection must be done in accordance with the new operator's schedule and inspection method.

(2) For airplanes that have not been inspected in accordance with this AD: The inspection of each PSE required by this AD must be done either before adding the airplane to the air carrier's operations specification, or in accordance with a schedule and an inspection method approved by the Manager, Los Angeles ACO. After each inspection has been done once, each subsequent inspection must be done in accordance with the new operator's schedule.

Acceptable for Compliance

(n) McDonnell Douglas Report No. MDC 91K0262, “DC-8 Aging Aircraft Repair Assessment Program Document,” Revision 1, dated October 2000, provides inspection/replacement programs for certain repairs to the fuselage pressure shell. Accomplishing these repairs and inspection/replacement programs before the effective date of this AD is considered acceptable for compliance with the requirements of paragraphs (g) and (l) of this AD for repairs subject to that document.

Alternative Methods of Compliance (AMOCs)

(o)(1) The Manager, Los Angeles ACO, has the authority to approve AMOCs for this AD, if requested in accordance with 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, Los Angeles ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane and 14 CFR 25.571, Amendment 45, and the approval must specifically refer to this AD.

(4) AMOCs approved previously in accordance with AD 93-01-15 are approved as AMOCs for the corresponding provisions of this AD.

Issued in Renton, Washington, on January 24, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.