Airworthiness directives: McDonnell Douglas,
[Federal Register: May 17, 2006 (Volume 71, Number 95)]
[Proposed Rules]
[Page 28622-28626]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17my06-17]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
[Docket No. FAA-2006-24787; Directorate Identifier 2006-NM-043-AD]
RIN 2120-AA64
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; Model MD-10-10F and MD-10-30F Airplanes; and Model MD-11 and MD-11F Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain McDonnell Douglas transport category airplanes. This proposed AD would require fabrication and installation of a wire harness guard in the right wheel well of the main landing gear (MLG), and related investigative and corrective actions as necessary. For certain airplanes, the proposed AD also would require replacement of the electrical connectors of the auxiliary hydraulic pumps with improved electrical connectors and related investigative and corrective actions. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent damage to the wire support bracket and wiring of the auxiliary hydraulic pump and, for certain airplanes, water intrusion through the electrical connectors of the auxiliary hydraulic pump. These conditions could lead to a potential ignition source in the right wheel well of the MLG around the fuel tank, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
DATES: We must receive comments on this proposed AD by July 3, 2006.
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.
Contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024), for the service information identified in this proposed AD.
FOR FURTHER INFORMATION CONTACT: Ken Sujishi, Aerospace Engineer, Cabin Safety/Mechanical and Environmental Systems Branch, ANM-150L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5353; fax (562) 627-5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number ``FAA-2006- 24787; Directorate Identifier 2006-NM-043-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 that 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 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.
Examining the Docket
You may examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.
Discussion
The FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, we issued a regulation titled ``Transport Airplane Fuel Tank System Design
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Review, Flammability Reduction and Maintenance and Inspection Requirements'' (67 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (``SFAR 88,'' Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the rule, we intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.
In evaluating these design reviews, we have established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: single failures, single failures in combination with a latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.
We have determined that the actions identified in this AD are necessary to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
We have received two reports indicating that the auxiliary hydraulic pump system failed on McDonnell Douglas Model DC-10-30F airplanes. Failure of the hydraulic pump resulted in several feet of burnt electrical wiring between the auxiliary hydraulic pump motor and the right wheel well of the main landing gear (MLG). Operators also found damage to the adjacent structure, control cables, hydraulic pipes, and hoses. Investigation revealed that electrical arcing between damaged wiring and the adjacent structure caused a short in the pump motor, which led to the failure of the hydraulic pump. The damaged wiring was caused by maintenance personnel stepping on the wiring assembly. Damage to the wire support bracket and wiring, if not corrected, could lead to a potential ignition source in the right wheel well of the MLG around the fuel tank, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
We have also received a third report that the auxiliary hydraulic pump failed on a McDonnell Douglas Model DC-10 airplane. Investigation of the third report revealed that water entered into the auxiliary hydraulic pump through the electrical connectors, causing electrical arcing. The electrical arcing led to the failure of the hydraulic pump. Water intrusion through the electrical connectors of the auxiliary hydraulic pump, if not corrected, could lead to a potential ignition source in the right wheel well of the MLG around the fuel tank, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
Other Related Rulemaking
On February 26, 2004, we issued AD 2004-05-20, amendment 39-13515 (69 FR 11504, March 11, 2004). That AD is applicable to certain 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; Model MD-10-10F and MD-10-30F airplanes; and Model MD-11 and MD-11F airplanes. That AD requires modification of the installation wiring for the electric motor operated auxiliary hydraulic pumps in the right wheel well area of the main landing gear, and repetitive inspections of the numbers 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions if necessary. We issued that AD to prevent failure of the electric motors of the hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure. The repetitive inspections of that AD ensure that any damage to the wiring of the auxiliary hydraulic pumps can be detected and corrected.
Relevant Service Information
We have reviewed the following service information:
Airplanes
Service bulletin
Dated
McDonnell Douglas Model DC-10-10 and DC- Boeing Alert Service
April 6, 2005. 10-10F airplanes; Model DC-10-15
Bulletin DC10-29A146, airplanes; Model DC-10-30 and DC-10-30F Revision 1. (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. McDonnell Douglas DC-10 September 8, 1993. Service Bulletin 29-135. McDonnell Douglas Model MD-11 and MD-11F Boeing Alert Service
April 30, 2001. airplanes.
Bulletin MD11-29A060.
Boeing Alert Service Bulletins DC10-29A146 and MD11-29A060 describe procedures for fabricating a wire harness guard and installing it in the right wheel well of the main landing gear (MLG), and doing related investigative and corrective actions. The related investigative actions are a visual inspection of the wiring installations of the auxiliary hydraulic pump in the right main wheel well at station Y = 1381 for chafing; and verification that the area around the wiring of auxiliary hydraulic pump is clean and free of debris. The corrective action is to repair any damaged or chafed wiring.
McDonnell Douglas DC-10 Service Bulletin 29-135 describes procedures for replacing the electrical connectors, having part number (P/N) FC6DE24-10S or DC62E24-10SN, of the auxiliary hydraulic pumps at the right wheel well of the MLG with improved electrical connectors having P/N DC62F24-10SN, and doing a related investigative action. The related investigative action is a test of the auxiliary hydraulic system.
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Accomplishing the actions specified in the service information 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 airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under ``Differences Between the Proposed AD and Service Bulletins.''
Differences Between the Proposed AD and Service Bulletins
Boeing Alert Service Bulletins DC10-29A146 and MD11-29A060 describe procedures for verifying that the area around the wiring of auxiliary hydraulic pump is clean and free of debris. However, the service bulletins do not specify what corrective action to take if any debris is found in the area around the wiring of the auxiliary hydraulic pump. This NPRM proposes to require cleaning the area of the debris before further flight.
Although Boeing Alert Service Bulletins DC10-29A146 and MD11-29A060 recommend accomplishing the modification within a compliance time of 18 months, this NPRM would require a compliance time of 60 months. Since issuance of those service bulletins, the manufacturer has reviewed the identified unsafe condition in response to SFAR 88. As a result, the manufacturer recommends extending the compliance time to 60 months because the unsafe condition occurs in an area outside of the fuel tank. Also as stated previously, we issued AD 2004-05-20 that in part requires repetitive inspections of the auxiliary hydraulic pumps at intervals of 2,500 flight hours. AD 2004-05-20 ensures that any damage to the wiring of the auxiliary hydraulic pumps can be detected and corrected. For these reasons, we find that a compliance time of 60 months represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety.
This NPRM identifies the correct P/N for a certain rivet that is incorrectly specified in Boeing Alert Service Bulletin MD11-29A060. P/N MS20470AD5-7, shown in the parts and material table in paragraph 2.C.2 of the service bulletin, is not a valid P/N. The correct P/N that must be used is P/N MS20470AD6-7; this P/N is correctly referenced in Figure 2 of the Accomplishment Instructions of the service bulletin. The manufacturer is aware of this discrepancy, concurs with the change, and has issued Information Notice MD11-29A060 IN 01, dated August 15, 2002, to inform operators of the error. We have included this information in paragraph (g) of this NPRM.
McDonnell Douglas DC-10 Service Bulletin 29-135 specifies testing the auxiliary hydraulic system, but does not specify what corrective action to take if the auxiliary hydraulic system fails that test. This NPRM proposes to require, before further flight, repairing the auxiliary hydraulic system according to a method approved by the Manager, Los Angeles Aircraft Certification Office, FAA. Chapter 29-20- 00 of the DC-10 Aircraft Maintenance Manual is one approved method for repairing the auxiliary hydraulic system.
Although McDonnell Douglas DC-10 Service Bulletin 29-135 recommends accomplishing the replacements at the earliest practical maintenance period, we have determined that this imprecise compliance time would not address the identified unsafe condition in a timely manner. In developing an appropriate compliance time for this NPRM, we considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the replacements. In light of all of these factors, we find a compliance time of 60 months for completing the replacements to be warranted, in that it represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety. This difference has been coordinated with the manufacturer.
Clarification of Concurrent Requirements
Boeing Alert Service Bulletin DC10-29A146 recommends accomplishing Boeing Service Bulletins DC10-29A144 and DC10-29A142 concurrently for ease of maintenance and scheduling. Also, Boeing Alert Service Bulletin MD11-29A060 recommends accomplishing Boeing Service Bulletins MD11- 29A059 and MD11-29A057 concurrently for ease of maintenance and scheduling. This NPRM, however, would not require operators to accomplish any of these service bulletins concurrently.
Clarification of Inspection Terminology
The ``visual inspection'' specified in Boeing Alert Service Bulletins DC10-29A146 and MD11-29A060 is referred to as a ``general visual inspection'' in this NPRM. We have included the definition for a general visual inspection in a note in this NPRM.
Costs of Compliance
There are about 627 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 303 airplanes of U.S. registry. The following table provides the estimated costs, at an average labor rate of $80 per hour, for U.S. operators to comply with this proposed AD.
Estimated Costs
Number of U.S.- Models
Action
Work Parts Cost per registered Fleet cost hours
airplane
airplanes
DC-10-10, DC-10-10F, DC-10- Fabrication and
3 $889
$1,129
206
$232,574 15, DC-10-30, DC-10-30F (KC- Installation. 10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, and MD- 10-30F airplanes. Replacement....
2 290
450
206
92,700 MD-11 and MD-11F airplanes... Fabrication and
3 866
1,106
97
107,282 installation.
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.
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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:
-
Is not a ``significant regulatory action'' under Executive Order 12866;
-
Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
-
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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):
McDonnell Douglas: Docket No. FAA-2006-24787; Directorate Identifier 2006-NM-043-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by July 3, 2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the McDonnell Douglas airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category.
(1) 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; fuselage numbers (FNs) 1 through 446 inclusive.
(2) Model MD-11 and MD-11F airplanes; F/Ns 0447, 0448, 0449, 0451 through 0464 inclusive, 0466 through 0489 inclusive, 0491 through 0517 inclusive, 0519 through 0552 inclusive, and 0554 through 0646 inclusive.
Unsafe Condition
(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent damage to the wire support bracket and wiring of the auxiliary hydraulic pump and, for certain airplanes, water intrusion through the electrical connectors of the auxiliary hydraulic pump. These conditions could lead to a potential ignition source in the right wheel well of the main landing gear (MLG) around the fuel tank, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.
Compliance
(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Installation and Replacement for Certain Airplanes
(f) For 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: Within 60 months after the effective date of this AD, do the actions specified in paragraph (f)(1) and (f)(2) of this AD.
(1) Fabricate a wire harness guard and install it in the right wheel well of the MLG, and do all related investigative and applicable corrective actions, by accomplishing all of the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin DC10-29A146, Revision 1, dated April 6, 2005; except as provided by paragraph (h) of this AD. Do all applicable corrective actions before further flight. If any debris is found in the area around the wiring of the auxiliary hydraulic pump, before further flight, clean the area of the debris.
(2) Replace any electrical connector having part number (P/N) DC62E24-10SN or FC6DE24-10S of the auxiliary hydraulic pumps at the right wheel well of the MLG with improved electrical connectors having P/N DC62F24-10SN, and do the related investigative action before further flight, by accomplishing all of actions specified in the Accomplishment Instructions of McDonnell Douglas DC-10 Service Bulletin 29-135, dated September 8, 1993. If the auxiliary hydraulic system fails the test, before further flight, repair the auxiliary hydraulic system according to a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Chapter 29-20-00 of the DC-10 Aircraft Maintenance Manual is one approved method.
Installation for Other Certain Airplanes
(g) For Model MD-11 and MD-11F airplanes: Within 60 months after the effective date of this AD, fabricate and install a wire harness guard in the right wheel well of the MLG, and do all related investigative and applicable corrective actions, by accomplishing all of the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin MD11-29A060, dated April 30, 2001; except as provided by paragraph (h) of this AD. Do all applicable corrective actions before further flight. If any debris is found in the area around the wiring of the auxiliary hydraulic pump, before further flight, clean the area of the debris. Rivet P/N MS20470AD5- 7, shown in the parts and material table in paragraph 2.C.2 of the service bulletin, is not a valid P/N; the correct P/N that must be used is P/N MS20470AD6-7.
Exception to Service Bulletins
(h) Where Accomplishment Instructions of Boeing Alert Service Bulletin DC10-29A146, Revision 1, dated April 6, 2005; and Boeing Alert Service Bulletin MD11-29A060, dated April 30, 2001, specify doing a visual inspection of the wiring installations of the auxiliary hydraulic pump in the right main wheel well at station Y=1381 for chafing, do a general visual inspection.
Note 1: For the purposes of this AD, a general visual inspection is: ``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 ensure visual access to all 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.''
Credit for Original Issue of Service Bulletin
(i) For 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: Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin DC10- 29A146, dated April 30, 2001,
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are acceptable for compliance with the corresponding requirements of this AD.
Alternative Methods of Compliance (AMOCs)
(j)(1) The Manager, Los Angeles ACO, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in accordance with Sec. 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.
Issued in Renton, Washington, on May 9, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E6-7475 Filed 5-16-06; 8:45 am]
BILLING CODE 4910-13-P
