Airworthiness Directives; McDonnell Douglas Model DC-10-10, and DC-10-10F Airplanes; Model DC-10-15 Airplanes; Model DC-10-30 and DC-10-30F (KC-10A and KDC-10) Airplanes; Model DC-10-40 and DC-10-40F Airplanes; and Model MD-10-10F and MD-10-30F Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for certain McDonnell Douglas transport category airplanes. That AD currently requires implementation of a program of structural inspections 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 would require the 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 is prompted by 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 September 17, 2004.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: (202) 493-2251.
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

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

FOR FURTHER INFORMATION CONTACT:

Ron Atmur, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5224; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2004-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2004-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-18670; Directorate Identifier 2002-NM-83-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of our docket Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

You may examine the AD docket 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 DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

On November 6, 1995, we issued Airworthiness Directive (AD) 95-23-09, amendment 39-9429 (60 FR 61649, December 1, 1995), for certain McDonnell Douglas transport category airplanes. That AD requires implementation of a program of structural inspections 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. That AD was prompted by data submitted by the manufacturer indicating that certain revisions to the program are necessary in order to clarify some principal structural elements (PSE) and some non-destructive inspection (NDI) procedures. We issued that AD to prevent fatigue cracking that could compromise the structural integrity of those airplanes.

Supplemental Inspection Documents (SIDs) ADs

In the early 1980's, 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

As a follow-on from that determination, we issued Advisory Circular (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.

SSID Team

In April 2000 the Transport Airplane Directorate (TAD) chartered a SSID Team to develop recommendations to standardize the SID/SSID ADs regarding the treatment of repairs, alterations, and modifications (RAMs). The report can be accessed at http://www.faa.gov/certification/aircraft/transport.htm.

FAA Responses to AASA

In addition to the SSID Team activity, there are other on-going activities associated with FAA's Aging Aircraft Program. This includes, among other initiatives, our responses to the AASA.

On November 1, 2002, as one of the responses to the AASA, we issued the Aging Airplane Safety Interim Final Rule (AASIFR) (67 FR 72726, December 6, 2002). The applicability of that rule addresses airplanes that are operated under part 121 of the FAR (14 CFR part 121), all U.S. registered multi-engine airplanes operated under part 129 of the FAR (14 CFR part 129), and all multi-engine airplanes used in scheduled operations under part 135 of the FARs (14 CFR part 135). The AASIFR requires the maintenance programs of those airplanes to include damage tolerance-based inspections and procedures that include all major structural RAMs. Currently, the ASSIFR requires that these procedures be established and incorporated within four years after December 8, 2003, the effective date specified by the AASIFR.

Public Technical Meeting

The TAD also held a public meeting regarding standardization of the FAA approach to RAMs in SID/SSID ADs on February 27, 2003, in Seattle, Washington. We presented our views and heard comments from the public concerning issues regarding the standardization of the requirements of ADs for certain transport category airplanes that mandate SSIDs, and that address the treatment of RAMs for those certain transport category airplanes. Our presentation included a plan for the standardization of SID/SSID ADs, the results of the SSID Team findings, and the TAD vision of how SID/SSID ADs may support compliance to the AASIFR. We also asked for input from operators on the issues addressing RAMs in SID/SSID ADs. One of the major comments presented at the public meeting was that operators do not have the capability to accomplish the damage tolerance assessments, and they will have to rely on the manufacturers to perform those assessments. Furthermore, the operators believe that the timeframes to accomplish the damage tolerance assessments will not permit manufacturers to support the operators. Another major comment presented was from the Airworthiness Assurance Working Group (AAWG) of the Aviation Rulemaking Advisory Committee (ARAC). The AAWG requested that we withdraw the damage tolerance requirements from the final rule and task AAWG to develop a new RAM damage tolerance based program with timelines to be developed by ARAC. The public meeting presentations can be accessed at http://www.faa.gov/certification/aircraft/transport.htm.

Explanation of Relevant Service Information

We have reviewed Boeing Report No. L26-012, “DC-10 Supplemental Inspection Document (SID),” Volume I, Revision 6, dated February 2002. The SID provides a description of PSEs and NDI procedures and thresholds with repetitive inspection intervals for inspections of PSEs. 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. Certain planning data (inspection threshold and repetitive inspections) and reporting requirements defined in Section 2 of Volume III-94, of the SID have been removed and are now included in Volume 1 of Revision 6 of the SID. We have determined that accomplishment of the actions specified in the service information will adequately address the unsafe condition.

We also have reviewed McDonnell Douglas Report No. MDC 91K0264, “DC-10/KC-10 Aging Aircraft Repair Assessment Program Document,” Revision 1, dated October 2000, which provides procedures to determine the appropriate inspection or replacement program for certain repairs to the fuselage pressure boundary. These repairs and inspection/replacement programs are acceptable alternative methods of compliance for the repair and repair inspection programs specified in this proposed AD.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the 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.

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. Therefore, we are proposing this AD, which would supersede AD 95-23-09. This proposed AD would continue to require revision of the FAA-approved maintenance program. This proposed AD would also 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. The following paragraphs summarize certain specific actions proposed in this AD.

Editorial Clarification of References

Paragraph (g) of AD 95-23-09 requires, among other things, that the maintenance program be revised to include the inspection threshold and repetitive inspections (planning data) defined in Section 2 of Volume III-94 of the SID. Paragraph (g)(4) of AD 95-23-09 also requires inspection results to be reported per Section 2 of Volume III-94. Those planning and data reporting requirements are now contained in Section 4 of Volume I, Revision 6, dated February 2002. Therefore, this NPRM proposes use of the information in Section 4 of Volume 1 of Revision 6, and reference to Volume III has been removed in the new requirements of this proposed AD.

Revision of the Maintenance Program

Paragraph (i) of the proposed AD would require a revision of the maintenance inspection program that provides for inspection(s) of the PSE per Boeing Report No. L26-012, “DC-10 Supplemental Inspection Document (SID),” Volume 1, Revision 6, dated February 2002. PSEs are also defined and specified in the SID. All references in this proposed AD to the “SID” are to Revision 6, dated February 2002.

Supplemental Inspection Program (SIP)

Paragraph (j) of the proposed AD would specify that the SIP 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-10 SID program is not a sampling program. All airplanes would be inspected once prior to 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 prior to 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 3 of Volume I of the SID. Inspection of each PSE should be accomplished in accordance with the NDI procedures set forth in Section 2 of Volume II, Revision 8, dated November 2003.

Once threshold N_th is passed, the PSE would be inspected at repetitive intervals not to exceed ΔNDI/2 as specified in Section 3 of Volume I of the SID per the NDI procedure, which is specified in Section 2 of 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.

SIP Inspection Requirements

Paragraph (k) of this proposed AD also would require, for airplanes that have exceeded the N_th, that each PSE be inspected prior to reaching the established thresholds (3/4N_th and N_th) or 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. If any PSE is repaired, altered, or modified, it must be reported as “discrepant.” A discrepant report indicates that a PSE 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).

Reporting Requirements

Paragraph (l) of this proposed AD would require that all negative, positive, or discrepant findings of the inspection accomplished in paragraph (b) of the AD be reported to Boeing at the times specified, and in accordance with, the instructions contained in Section 3 of Volume 1 of the SID.

Corrective Action

Paragraph (m) of this proposed AD would require that any cracked structure detected during any inspection required per paragraph (g) of this AD be repaired before further flight. Additionally, paragraph (i) of this AD would require accomplishment of follow-on actions as specified in paragraphs (i)(1), (i)(2), and (i)(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. Prior to 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. Prior to 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.

Transferability of Airplanes

Paragraph (n) 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 (n) 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 accomplished 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 accomplished by the previous operator. After each inspection has been performed once, each subsequent inspection must be performed 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 accomplished either prior to 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 performed 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 SSID.

Inspections Accomplished Previously

Paragraph (o) of this proposed AD merely provides approval of Boeing Report No. L26-012, “DC-10 Supplemental Inspection Document (SID),” Volume I, Revision 4, dated June 1993, and Revision 5, dated October 1994; and Volume II, Revision 6, dated October 1997, and Revision 7, dated August 2002; as acceptable for compliance with the requirements of paragraph (j) of this proposed AD for inspections accomplished prior to the effective date of the proposed AD.

Acceptable for Compliance

Paragraph (p) of this proposed AD also provides approval of McDonnell Douglas Report No. MDC 91K0264, “DC-10/KC-10 Aging Aircraft Repair Assessment Program Document,” Revision 1, dated October 2000, as an acceptable means compliance with the requirements of paragraphs (i) and (m) of this proposed AD for repairs and inspection/replacement for certain repairs to the fuselage pressure shell accomplished prior to the effective date of the proposed AD.

Change to Existing AD

This proposed AD would retain certain requirements of AD 95-23-09. Since AD 95-23-09 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:

Interim Action

This is considered to be interim action. We are currently considering requiring damage tolerance-based inspections and procedures that include all major structural RAMs, which may result in additional rulemaking. That rulemaking may include appropriate recommendations from the previously mentioned FAA team and a public meeting on how to address RAMs.

Costs of Compliance

There are about 419 McDonnell Douglas transport category airplanes worldwide of the affected design. This proposed AD would affect about 249 airplanes of U.S. registry and 13 U.S. operators.

The incorporation of the SID program into an operator's maintenance program, as required by AD 95-23-09, and retained in this proposed AD takes about 1,290 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the cost to the 13 affected U.S. operators to incorporate the SID program is estimated to be $1,090,050.

The recurring inspection costs, as required by AD 95-23-09, are estimated to be 365 work hours per airplane per year, at an average labor rate of $65 per work hour. Based on these figures, the recurring inspection costs required by AD 95-23-09 are estimated to be $23,725 per airplane, or $5,907,525 for the affected U.S. fleet.

Since no new recurring inspection procedures have been added to the program by this new proposed AD action, there is no additional economic burden on affected operators to perform any additional recurrent inspections.

Additionally, the number of required work hours for each proposed inspection (and the SID program), as indicated above, is presented as if the accomplishment of those actions were to be conducted as “stand alone” actions. However, in actual practice, these actions for the most part will be accomplished coincidently or in combination with normally scheduled airplane inspections and other maintenance program tasks. Further, any costs associated with special airplane scheduling are expected to be minimal.

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. 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.