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Proposed Rule

Airworthiness Directives; McDonnell Douglas Model MD-11 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

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Start Preamble

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 Model MD-11 series airplanes, that currently requires deactivation of the forward and center cargo control units (CCU). That AD was prompted by a report of failure of a CCU, which produced overheating of the electrical pins inside the CCU; the subsequent release of hot gases and flames ignited an adjacent insulation blanket. This action would require, among other actions, a general visual inspection to verify that all six external connectors of suspect CCU's have a certain part number stamped on the connector bodies on all CCU assemblies, and follow-on actions, which would constitute terminating action for the deactiviation requirements. The actions specified by the proposed AD are intended to prevent overheating of the electrical pins inside the CCU's and subsequent release of hot gases and flames, which could result in smoke and fire in the cargo compartment.

DATES:

Comments must be received by September 11, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket

No. 2000-NM-38-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-38-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: Technical Publications Business Administration, Dept. C1-L51 (2-60). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Brett Portwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5350; fax (562) 627-5210.

End Further Info End Preamble Start Supplemental Information

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 notice 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-38-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. 2000-NM-38-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On April 12, 2000, the FAA issued AD 2000-08-03, amendment 39-11689 (65 FR 21134, April 20, 2000), applicable to certain McDonnell Douglas Model MD-11 series airplanes, to require deactivation of the forward and center cargo control units (CCU).

That action was prompted by a report of failure of a CCU, which produced overheating of the electrical pins inside the CCU; the subsequent release of hot gases and flames ignited an adjacent insulation blanket. The requirements of that AD are intended to prevent overheating of the electrical pins inside the CCU's and subsequent release of hot gases and flames, which could result in smoke and fire in the cargo compartment.

Actions Since Issuance of Previous Rule

In the preamble of AD 2000-08-03, the FAA indicated that the actions required by that AD were considered “interim action” and that further rulemaking was being considered to require modification of the CCU assembly, which would constitute terminating action for the requirements of AD 2000-08-03. The FAA now has determined that further rulemaking is indeed necessary, and this proposed AD follows from that determination.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin MD11-25A253, dated March 10, 2000. The service bulletin describes procedures for a general visual inspection to verify that all six external connectors of the CCU's have a certain part number stamped on the connector bodies on all TRW Aeronautical Systems, Lucas Aerospace, CCU assemblies; and follow-on actions. The follow-on actions include: Start Printed Page 46224Returning any discrepant connector to the manufacturer; modifying the rear cover (40) of the CCU assembly [including aligning the center hole of the insulator with the center hole on the rear cover (40); ensuring that the top edge of the insulator is parallel to the top edge of the rear cover]; and reidentifying the CCU; as applicable. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Boeing Alert Service Bulletin MD11-25A253 references TRW Aeronautical Systems, Lucas Aerospace Alert Service Bulletin 462650-25-A01, dated March 10, 2000, as an additional source of service information to accomplish the inspection and follow-on actions described above.

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 2000-08-03 to continue to require deactivation of the forward and center CCU's, until accomplishment of the actions specified in Boeing Alert Service Bulletin MD11-25A253 described previously. The proposed AD also would require an inspection to determine the part number of the CCU's, and accomplishment of the actions specified in the Boeing service bulletin described previously, if necessary, except as discussed below.

Differences Between the Proposed AD and Relevant Service Bulletin

Although Boeing Alert Service Bulletin MD11-25A253 recommends accomplishing the general visual inspection within 15 days (from issue date of the service bulletin), the FAA has determined that an interval of 90 days would address the identified unsafe condition in a timely manner. Because operators have already accomplished the interim requirements (i.e., deactivation of the discrepant CCU's) of AD 2000-08-03 (which includes the requirements of AD 2000-05-01), the FAA finds that the safety risk of the affected airplanes has been reduced. Therefore, the FAA has determined that a 90-day compliance time for initiating the required inspection to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Boeing Alert Service Bulletin MD11-25A253 (which, as described previously, references TRW Aeronautical Systems, Lucas Aerospace Alert Service Bulletin 462650-25-A01 as an additional source of service information) recommends that certain discrepant CCU's be returned to the manufacturer; however, it does not describe any further procedures to correct the discrepancy. Therefore, this proposed AD requires replacement of the discrepant CCU with a CCU that has one of the following part numbers (P/N): 462650-21, 462650-22, or 462650-23.

Since the issuance of Boeing Alert Service Bulletin MD11-25A253, Lucas has incorporated a design change to the CCU's. Lucas incorporated this design change in CCU's having P/N 462650-21, 462650-22, and 462650-23. The FAA finds that these CCU's are not subject to the identified unsafe condition of this AD. Therefore, in addition to the procedures in the referenced service bulletin, this proposed AD would require a general visual inspection to determine the part number of the CCU's. Depending on the inspection results, the proposed AD would then require a general visual inspection to verify that all six external connectors of the suspect CCU have a certain part number stamped on the connector bodies on all CCU assemblies, as described in the referenced service bulletin, and follow-on actions.

Cost Impact

There are approximately 104 Model MD-11 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 20 airplanes of U.S. registry would be affected by this proposed AD.

The actions that are currently required by AD 2000-08-03 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 the currently required actions on U.S. operators is estimated to be $1,200, or $60 per airplane.

The new inspection that is proposed in this AD action 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 the inspection proposed by this AD on U.S. operators is estimated to be $1,200, or $60 per airplane.

Should an operator be required to accomplish the new modification that is proposed in this AD action, it would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer of the CCU at no cost to the operators. Based on these figures, the cost impact of the modification proposed by this AD on U.S. operators is estimated to be $60 per airplane.

Should an operator be required to accomplish the new replacement that is proposed in this AD action, it would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer of the CCU at no cost to the operators. Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $60 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows: Start Printed Page 46225

Start Authority

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

End Authority
[Amended]

2. Section 39.13 is amended by removing amendment 39-11689 (65 FR 21134, April 20, 2000), and by adding a new airworthiness directive (AD), to read as follows:

McDonnell Doulgas: Docket 2000-NM-38-AD. Supersedes AD 2000-08-03, Amendment 39-11689.

Applicability: Model MD-11 series airplanes, certificated in any category, having the serial numbers listed below.

Group 1 Airplane
485654856648533485494847048406
485044860248603485714843948605
485724847148573486004860148633
485134857448575485424854348576
484154863148544486324857748545
485784854648743487444874748748
487454874648749485794876648768
487674876948754486234877048753
4877348774487554875848775-48779 (inclusive)
48624487564878048532
Group 2 Airplane
485554855648581486304855748539
485584855948616485604861748618
485614862948562485634875748540
4856448634485414879848781-48792 (inclusive)
4879448799488014880048802-48806 (inclusive)

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) 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 prevent overheating of the electrical pins inside the cargo control units (CCU) and subsequent release of hot gases and flames, which could result in smoke and fire in the cargo compartment, accomplish the following:

Restatement of Requirements of AD 2000-05-01: Deactivation

(a) For Group 1 airplanes having serial numbers other than that identified in paragraph (c) of this AD: Within 15 days after March 20, 2000 (the effective date of AD 2000-05-01, amendment 39-11610), deactivate the forward and center CCU's in accordance with the following procedures:

(1) Remove the access panel to the forward cargo compartment CCU circuit breaker panel located at fuselage station 1009.300 (right side looking aft). Pull and collar the following circuit breakers:

B1-506B1-489B1-488B1-487B1-486
B1-485B1-480B1-481B1-498B1-482
B1-500B1-495B1-499B1-490

(2) Remove the access panel to the center cargo compartment CCU circuit breaker panel located at fuselage station 1701.000 (right side looking aft). Pull and collar the following circuit breakers:

B1-552B1-762B1-761B1-760B1-759
B1-758B1-518B1-519B1-751B1-520
B1-753B1-764B1-752B1-763

(b) For Group 2 airplanes having serial numbers other than that identified in paragraph (c) of this AD: Within 15 days after March 20, 2000, deactivate the forward and center CCU's in accordance with the following procedures:

(1) Remove the access panel to the forward cargo compartment CCU circuit breaker panel located at fuselage station 1009.300 (right side looking aft). Pull and collar the following circuit breakers:

B1-506B1-489B1-488B1-487B1-486
B1-485B1-480B1-481B1-498B1-482
B1-500B1-495B1-499B1-490

(2) Remove the access panel to the center cargo compartment CCU circuit breaker panel located at fuselage station 1701.000 (right side looking aft). Pull and collar the following circuit breakers:

B1-552B1-762B1-761B1-760B1-759
B1-758B1-518B1-519B1-751B1-520
B1-753B1-764B1-752
Start Printed Page 46226

Restatement of Requirements of AD 2000-08-03: Deactivation

(c) For Group 1 airplane, serial number 48769, and for Group 2 airplane, serial number 48563: Within 15 days after May 5, 2000 (the effective date of AD 2000-08-03, amendment 39-11689), accomplish the actions specified in either paragraph (a) or (b) of this AD, as applicable.

New Requirements of This AD: Inspection and Modification/Reidentification, If Necessary

(d) For Group 1 and Group 2 airplanes: Within 90 days after the effective date of this AD, perform an inspection to determine the part number of the CCU's.

(1) If both CCU's have part number (P/N) 462650-21, 462650-22, or 462650-23, the deactivation specified in paragraphs (a), (b), and (c) of this AD is no longer required, and the CCU's may be reactivated.

(2) If any CCU has a part number (P/N) other than 462650-21, 462650-22, or 462650-23, within 90 days after the effective date of this AD, perform a general visual inspection to verify that all six external connectors of the CCU have P/N M83723/71XXXXXX or P/N M83723/72XXXXXX stamped on the connector bodies on all TRW Aeronautical Systems, Lucas Aerospace, CCU assemblies, in accordance with Boeing Alert Service Bulletin MD11-25A253, dated March 10, 2000.

Note 2:

McDonnell Douglas Service Bulletin MD11-25A253, dated March 10, 2000, references TRW Aeronautical Systems, Lucas Aerospace Alert Service Bulletin 462650-25-A01, dated March 10, 2000, as an additional source of service information to accomplish the inspection described above and corrective actions described below.

(i) If any connector has a P/N other than M83723/71XXXXXX or M83723/72XXXXXX, prior to further flight, replace the CCU with a spare CCU from the operator's stock that has one of the following P/N: 462650-21, 462650-22, or 462650-23. Following accomplishment of the replacement, the deactivation specified in paragraphs (a), (b), and (c) of this AD is no longer required, and the CCU's may be reactivated.

(ii) If any connector has P/N M83723/71XXXXXX or P/N M83723/72XXXXXX, prior to further flight, modify the rear cover (40) of the CCU assembly [including aligning the center hole of the insulator with the center hole on the rear cover (40), and ensuring that the top edge of the insulator is parallel to the top edge of the rear cover), and reidentify the CCU, in accordance with the service bulletin. Following accomplishment of the modification, the deactivation specified in paragraphs (a), (b), and (c) of this AD is no longer required, and the CCU's may be reactivated.

Spares

(e) As of the effective date of this AD, no person shall install on any airplane any part (identified under “Key Word”), having a “Spare Part No.” listed in paragraph 2.D., “Parts Necessary to Change Spares,” of Boeing Alert Service Bulletin MD11-25A253, dated March 10, 2000.

Alternative Methods of Compliance

(f) 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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.

Note 3:

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.

Start Signature

Issued in Renton, Washington, on July 14, 2000.

John J. Hickey,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 00-18402 Filed 7-26-00; 8:45 am]

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