AD 98-14-17

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AD Number:
98-14-17
Document Type:
AD Final Rules
Docket Number:
98-NM-145-AD
Subject Heading:
Airworthiness Directives; Boeing Model 747 Series Airplanes
Subject:
Scavenge Pump Motor-Impeller Unit
Status:
Current
Citation:
(Federal Register: July 08, 1998 (Volume 63, Number 130))
Citation Publish Date:
07/08/1998
Effective Date:
07/23/1998
Make:
The Boeing Company
Model:
747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 (63 FR 36836 NO. 130 07/08/98)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 98-14-17
CITATION:   [Federal Register: July 08, 1998 (Volume 63, Number 130)]

PAGE NUMBER:   [Page 36836]

DOCKET NUMBER:   98-NM-145-AD

AMENDMENT:   39-10650

AD NUMBER:   98-14-17

SUBJECT HEADING:   Airworthiness Directives; Boeing Model 747 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:  
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires disconnection of the electrical connector to the scavenge pump of the center wing tank. That AD also requires a one-time inspection to identify the part number of the electrical connector; and replacement of the pump with a new or serviceable pump, if necessary. This amendment requires a one-time inspection to identify the part number of the scavenge pump motor-impeller unit; and corrective action, if necessary. This amendment is prompted by a report of damage to the internal wiring of a scavenge pump that had been replaced in accordance with the existing AD. The actions specified in this AD are intended to prevent potential failures within the electrical motor assembly of the scavenge pump, which could result in leakage of fuel from the electrical connector into the main landing gear wheel well, or electrical arcing within the scavenge pump motor; these conditions could result in a fuel fire in the wheel well.

DATES:   Effective July 23, 1998. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of July 23, 1998. Comments for inclusion in the Rules Docket must be received on or before September 8, 1998.

ADDRESSES:  
Submit comments in triplicate to the Federal Aviation Administration (FAA),
Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-145-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:  
Chris Hartonas, Aerospace Engineer, Systems & Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2864; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:  
On November 26, 1997, the FAA issued AD 97-25-06, amendment 39-10230 (62 FR 63622, December 1, 1997), applicable to certain Boeing Model 747 series airplanes. [A correction of the rule was published in the Federal Register on January 2, 1998 (63 FR 4).] That action requires disconnection of the electrical connector to the scavenge pump of the center wing tank; a one-time inspection to identify the part number of the electrical connector; and replacement of the pump with a new or serviceable pump, if necessary. That action was prompted by findings from a design review and analysis of scavenge pumps installed on certain Boeing Model 747 series airplanes that was undertaken as part of an accident investigation. The actions required by that AD are intended to prevent potential failures within the electrical motor assembly of the scavenge pump, which could result in leakage of fuel from the electrical connector into the main landing gear wheel well, or electrical arcing within the scavenge pump motor; these conditions could result in a fuel fire in the wheel well.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the FAA has received a report of damage to the internal wiring of a scavenge pump; the connector of that scavenge pump had been replaced with a Lear Romec- supplied connector, in accordance with the requirements of the existing AD. The damage to the wiring has been attributed to that replacement connector's longer backshell, which provides insufficient clearance for the attachment screw of the internal ground wire of the scavenge pump motor, and can cause interference between the screw and the connector. Such wiring damage, if not corrected, could cause short circuiting and failures within the electrical motor assembly; such failures could result in leakage of fuel from the electrical connector into the main landing gear wheel well, or electrical arcing within the scavenge pump motor, and consequent fuel fire in the wheel well.

Explanation of Relevant Service Information

As a result of this recent finding, Boeing has issued Alert Service Bulletin 747-28A2215, dated May 14, 1998, which describes procedures for a one-time inspection to identify the part number for the installed scavenge pump motor-impeller unit; and corrective action, if necessary. The alert service bulletin provides operators a choice of three corrective actions. First, operators may replace the scavenge pump with a different model scavenge pump. Second, operators may replace the scavenge pump with a scavenge pump that has been modified in accordance with Lear Romec Service Bulletin RR24680 28-002, dated May 4, 1998. (Lear Romec is the manufacturer of the subject scavenge pump.) This modification involves removal of the connector ground jumper lead wire and its attachment screw. Accomplishment of the modification will provide additional room for, and will prevent short circuit damage to, the wires inside the scavenge pump motor. Third, operators may deactivate the scavenge pump. The FAA has reviewed and approved the Boeing and Lear Romec service bulletins.

Explanation of Requirements of Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 97-25-06 to require a one-time inspection to identify the part number for the installed scavenge pump motor-impeller unit; and corrective action, if necessary.

Differences Between this AD and the Relevant Service Information

This AD differs from Boeing Alert Service Bulletin 747-28A2215, dated May 14, 1998. The alert service bulletin specifies that the scavenge pump may be replaced with a scavenge pump having "a different part number." However, this AD specifically requires that the replacement scavenge pump be either a scavenge pump having part number 60B92403-12, -13, or -18 (Intertechnique); or a scavenge pump that has been modified in accordance with Lear Romec Service Bulletin RR24680 28-002, dated May 4, 1998.

Also, the Boeing alert service bulletin specifies that a modified pump may be reidentified as having one of two given part numbers. However, this AD requires that the pump modified in accordance with Lear Romec Service Bulletin RR24680 28-002 be reidentified as Boeing P/N 60B92403-51.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-NM-145-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by Reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 39-10230 (63 FR 4, January 2, 1998), and by adding a new airworthiness directive (AD), amendment 39-10650, to read as follows:

REGULATORY TEXT:  
98-14-17 BOEING: Amendment 39-10650. Docket 98-NM-145-AD. Supersedes AD 97-25-06, Amendment 39-10230.

Applicability: Model 747 series airplanes, line positions 001 through 971 inclusive; certificated in any category.

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 (c) 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 potential failures within the electrical motor assembly of the scavenge pump, which could result in leakage of fuel from the electrical connector into the main landing gear wheel well, electrical arcing within the scavenge pump motor, or a fuel fire in the wheel well; accomplish the following:

(a) Within 60 days after the effective date of this AD, perform a one-time inspection to determine the part number (P/N) of the installed scavenge pump motor-impeller unit, in accordance with Boeing Alert Service Bulletin 747-28A2215, dated May 14, 1998.

(1) If the P/N is neither Boeing P/N 60B92403-5 nor Lear Romec P/N RR24680, no further action is required by this AD.

(2) If the P/N is either Boeing P/N 60B92403-5 or Lear Romec P/N RR24680, prior to further flight, accomplish paragraph either (a)(2)(i) or (a)(2)(ii) of this AD.

(i) Replace the scavenge pump with a new or serviceable scavenge pump having P/N 60B92403-12, -13, or -18 (Intertechnique); or with a new or serviceable scavenge pump having P/N 60B92403-51 (Lear Romec).

(ii) Deactivate the scavenge pump. The airplane may be operated with the scavenge pump deactivated, in accordance with the provisions and limitations specified in the operator's FAA-approved Master Minimum Equipment List.

NOTE 2: Boeing Alert Service Bulletin 747-28A2215, dated May 14, 1998, refers to the 747 Dispatch Deviation Guide as another source of service information for deactivation of the scavenge pump.

(b) As of the effective date of this AD, no person shall install on any airplane a scavenge pump having either Boeing P/N 60B92403-5 or Lear Romec P/N RR24680.

(c) 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, Seattle 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, Seattle ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(d) 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.

(e) The actions shall be done in accordance with Boeing Alert Service Bulletin 747-28A2215, dated May 14, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on July 23, 1998.

FOOTER: