02-22133. Airworthiness Directives; McDonnell Douglas DC-9-10, -20, -30, -40, and -50 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas DC-9-10, -20, -30, -40, and -50 series airplanes. The existing AD requires a one-time visual inspection to determine the modification status of the corners of the forward lower cargo doorjamb; low-frequency eddy current inspections to detect cracks of the fuselage skin and doubler at all corners of the forward lower cargo doorjamb; various follow-on repetitive inspections; and modification, if necessary. This action would retain those requirements but would require certain high-frequency, rather than low-frequency, eddy current inspections for certain conditions. The actions specified by the proposed AD are intended to detect and correct cracking, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by October 15, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-78-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-78-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

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

Other Information: Sandi Carli, Airworthiness Directive Technical Editor/Writer; telephone [phone], fax [phone]. Questions or comments may also be sent via the Internet using the following address: [e-mail]. Questions or comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-78-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-78-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On April 9, 1998, the FAA issued AD 98-08-24, amendment 39-10473 (63 FR 19180, April 17, 1998), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes, and Model C-9 (military) airplanes, to require a one-time visual inspection to determine the modification status of the corners of the forward lower cargo doorjamb; low-frequency eddy current (LFEC) inspections to detect cracks of the fuselage skin and doubler at all corners of the forward lower cargo doorjamb; various follow-on repetitive inspections; and modification, if necessary. That action was prompted by reports of fatigue cracks found in the fuselage skin and doubler at the corners of the forward lower cargo doorjamb. The requirements of that AD are intended to detect and correct such fatigue cracking, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the manufacturer has advised the FAA of an error in the procedures for inspecting the modified or repaired corners of the forward lower cargo doorjamb. The service bulletin identified in AD 98-08-24 refers to the DC-9 Structural Repair Manual (SRM), which specified that those inspections be done using LFEC methods. The FAA and the manufacturer have determined that LFEC inspections would be inadequate to determine the type and extent of the cracking for the modified or repaired corners of the forward lower cargo doorjamb. The manufacturer instead recommends that those inspections be done using high-frequency eddy current (HFEC) methods for those modified or repaired corners. The SRM has been revised to specify use of the new inspection method.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Service Bulletin DC9-53-277, Revision 01, dated June 16, 1999. The original version of this service bulletin, dated September 30, 1996, was cited in AD 98-08-24 as the appropriate source of service information for accomplishment of certain required actions. The revised service bulletin refers to the revised SRM, which specifies HFEC rather than LFEC inspections of the modified or repaired corners. The remaining actions are unchanged. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Related Rulemaking

Accomplishment of the actions required by this AD constitutes terminating action for inspections of Principal Structural Element 53.09.001 (reference McDonnell Douglas Model DC-9 SID) required by AD 96-13-03, amendment 39-9671 (61 FR 31009, June 19, 1996).

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 supersede AD 98-08-24 to continue to require a one-time inspection to determine the modification status of all corners of the forward lower cargo doorjamb, various follow-on repetitive inspections, and modification if necessary; and to require HFEC (rather than the currently required LFEC) inspections to detect cracks of the fuselage skin and doubler at the modified or repaired corners of the forward lower cargo doorjamb. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed in the following section.

Differences Between Proposed AD and Service Bulletin

Although the service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA.

Explanation of Changes to Existing Requirements

Paragraph (d) of AD 98-08-24 has been revised in this proposed AD to provide an additional compliance time variable for operators unable to determine the date of the modification, if accomplished.

The FAA has clarified the inspection requirement contained in the proposed AD. Whereas AD 98-08-24 requires a “visual inspection,” the FAA has revised this proposed AD to clarify that its intent is to require a “general visual inspection.” Additionally, new Note 4 has been added to this proposed AD to define that inspection.

The FAA has revised the applicability of the existing AD to identify model designations as published in the most recent type certificate data sheet for the affected models.

Cost Impact

There are approximately 899 airplanes of the affected design in the worldwide fleet. The FAA estimates that 622 airplanes of U.S. registry would be affected by this proposed AD.

The inspection that is currently required by AD 98-08-24, and retained in this proposed AD, takes approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions is estimated to be $60 per airplane.

Should an operator be required to accomplish an eddy current inspection, it would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of an eddy current inspection proposed by this AD is estimated to be $60 per airplane.

Should an operator be required to accomplish the modification, it would take approximately 14 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $936 or $2,807 per airplane, depending on the service kit purchased. Based on these figures, the cost impact of the modification required by this AD is estimated to be $1,776 or $3,647 per airplane.

No change to the parts cost or work hour estimate is anticipated as a result of the new actions included in this proposed AD.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-10473 (63 FR 19180, April 17, 1998), and by adding a new airworthiness directive (AD), to read as follows:

McDonnell Douglas: Docket 2001-NM-78-AD. Supersedes AD 98-08-24, Amendment 39-10473.

Applicability: Model DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, and DC-9-15F airplanes; DC-9-21 airplanes; DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, and DC-9-32F (C-9A, C-9B) airplanes; DC-9-41 airplanes; and DC-9-51 airplanes; certificated in any category; as listed in McDonnell Douglas Service Bulletin DC9-53-277, Revision 01, dated June 16, 1999.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f)(1) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct cracking in the fuselage skin or doubler at the corner of the forward lower cargo doorjamb, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane, accomplish the following:

Note 2:

Where there are differences between the service bulletin and the AD, the AD prevails.

Note 3:

This AD is related to AD 96-13-03, amendment 39-9671; and AD 94-03-01, amendment 39-8807. This AD will affect Principal Structural Element (PSE) 53.09.001 of the DC-9 Supplemental Inspection Document (SID).

One-time Inspection

(a) Prior to the accumulation of 48,000 total landings, or within 3,500 landings after May 22, 1998 (the effective date of AD 98-08-24, amendment 39-10473), whichever occurs later: Perform a one-time general visual inspection to determine if the corners of the forward lower cargo doorjamb have been modified.

Note 4:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Follow-On Actions: Unmodified Doorjamb

(b) If the general visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb have NOT been modified: Before further flight, perform a low-frequency eddy current (LFEC) or X-ray inspection to detect cracks of the fuselage skin and doubler at all corners of the forward lower cargo doorjamb, in accordance with McDonnell Douglas Service Bulletin DC9-53-277, dated September 30, 1996; or Revision 01, dated June 16, 1999. After the effective date of this AD, Revision 1 of the service bulletin must be used.

(1) If no cracking is detected during the LFEC or X-ray inspection required by this paragraph, accomplish the requirements of either paragraph (b)(1)(i) or (b)(1)(ii) of this AD.

(i) Option 1. Repeat the inspections as follows until the actions specified in paragraph (b)(1)(ii) of this AD is accomplished:

(A) If the immediately preceding inspection was conducted using LFEC techniques, conduct the next inspection within 3,500 landings; or

(B) If the immediately preceding inspection was conducted using X-ray techniques, conduct the next inspection within 2,850 landings.

(ii) Option 2. Before further flight, modify the corners of the forward lower cargo doorjamb, in accordance with the service bulletin. Within 28,000 landings after accomplishment of that modification, perform a high-frequency eddy current inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin. Repeat the HFEC inspection thereafter at intervals not to exceed 20,000 landings.

(A) If no crack is detected on the skin adjacent to the modification during any HFEC inspection required by this paragraph: Repeat the HFEC inspection thereafter at intervals not to exceed 20,000 landings.

(B) If any crack is detected on the skin adjacent to the modification during any HFEC inspection required by this paragraph: Before further flight, repair it in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA.

(2) If any crack is found during any LFEC or X-ray inspection required by this paragraph and the crack is 2 inches or less in length: Before further flight, modify it in accordance with the service bulletin. Within 28,000 landings after accomplishment of the modification, perform an HFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with the service bulletin.

(i) If no crack is detected during the HFEC inspection required by this paragraph: Repeat the HFEC inspection thereafter at intervals not to exceed 20,000 landings.

(ii) If any crack is detected during the HFEC inspection required by this paragraph: Before further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO.

(3) If any crack is found during any LFEC or X-ray inspection required by this paragraph and the crack is greater than 2 inches in length: Before further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO.

Follow-On Actions: Doorjamb Modified per Other Than SRM/Drawing

(c) If the general visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb HAVE been modified, but not in accordance with the DC-9 Structural Repair Manual (SRM) or Service Rework Drawing: Before further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO.

Follow-On Actions: Doorjamb Modified per SRM/Drawing

(d) If the general visual inspection required by paragraph (a) of this AD reveals that the corners of the forward lower cargo doorjamb HAVE been modified in accordance with the DC-9 SRM or Service Rework Drawing: Within 28,000 landings since accomplishment of that modification, or within 3,500 landings after May 22, 1998, or before the accumulation of 48,000 total landings, whichever occurs latest, perform an HFEC inspection to detect cracks on the skin adjacent to the modification, in accordance with McDonnell Douglas Service Bulletin DC9-53-277, dated September 30, 1996; or Revision 01, dated June 16, 1999. After the effective date of this AD, Revision 01 of the service bulletin must be used. Repeat the HFEC inspection thereafter at intervals not to exceed 20,000 landings.

(1) If no crack is detected during any HFEC inspection required by this paragraph: Repeat the HFEC inspection thereafter at intervals not to exceed 20,000 landings.

(2) If any crack is detected during any HFEC inspection required by this paragraph: Before further flight, repair it in accordance with a method approved by the Manager, Los Angeles ACO.

(e) Accomplishment of the actions required by this AD constitutes terminating action for inspections of PSE 53.09.001 (reference McDonnell Douglas Model DC-9 SID) required by AD 96-13-03, amendment 39-9671.

Alternative Methods of Compliance

(f)(1) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles ACO, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

(2) Alternative methods of compliance approved in accordance with AD 98-08-24; AD 94-03-01, amendment 39-8807; or AD 96-13-03, amendment 39-9671; are acceptable for compliance with the applicable requirements of this AD.

(3) An alternative method of compliance for any inspection or repair required by this AD that provides an acceptable level of safety may be used in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Los Angeles ACO, to make such findings.

Note 5:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permits

(g) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on August 20, 2002.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.