### 30752 Federal Register / Vol. 73, No. 104 / Thursday, May 29, 2008 / Rules and Regulations

T ABLE 

### 2.

— D RAWINGS 

### I NCLUDED IN 

### F OKKER 

### S ERVICE 

### B ULLETIN 

### SBF100

– 22

– 050

— Continued

Fokker drawing Sheet Issue Date
W41504 ..................................................................... 011 J ............................................... ................................ April 25, 2006. W41504 ..................................................................... 012 L ............................................... ................................ April 25, 2006. W41504 ..................................................................... 013 L ............................................... ................................ April 25, 2006. W46140 ..................................................................... 27 AR ............................................... ............................. March 5, 2002. W46140 ..................................................................... 28 AR ............................................... ............................. March 8, 2002. W46143 ..................................................................... 02 K ................................................ ............................... February 26, 2002. W46143 ..................................................................... 03 K ................................................ ............................... March 7, 2002. W46144 ..................................................................... 06 R ................................................ ............................... March 4, 2002. W46144 ..................................................................... 07 S ................................................ ............................... March 7, 2002. W46912 ..................................................................... 01 D ................................................ ............................... March 12, 2002. W46930 ..................................................................... 01 Original ......................................... ............................ March 14, 2002. W46930 ..................................................................... 02 E ................................................ ............................... March 14, 2002. W46932 ..................................................................... 01 D ................................................ ............................... March 13, 2002. W59140 ..................................................................... 177 GC .............................................. .............................. February 8, 2006. W59140 ..................................................................... 178 GB .............................................. .............................. February 6, 2006. W59140 ..................................................................... 221 GB .............................................. .............................. February 6, 2006.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Fokker Services B.V., Technical Services Dept., P.O. Box 231, 2150 AE Nieuw-Vennep, the Netherlands.

(3) You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741

– 6030, or go to: http://www.archives.gov/federal-register/cfr/ibrlocations.html

.

Issued in Renton, Washington, on May 14, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8

– 11501 Filed 5

– 28

– 08; 8:45 am] **BILLING CODE 4910**

**– 13** 

**– P** 

**DEPARTMENT OF TRANSPORTATION Federal Aviation Administration** 
**14 CFR Part 39 [Docket No. FAA** 

**– 2008** 

**– 0544; Directorate**  **Identifier 2008**

**– NM** 

**– 099** 

**– AD; Amendment**  **39**

**– 15535; AD 2008** 

**– 10** 

**– 51]**  **RIN 2120**

**– AA64**  **Airworthiness Directives; Dornier Model 328** 

**– 100 and** 

**– 300 Airplanes** 
**AGENCY :**  Federal Aviation Administration (FAA), Department of Transportation (DOT). **ACTION :**  Final rule; request for comments.
**SUMMARY :**  This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2008

– 10

– 51 that was sent previously to all known U.S. owners and operators of all Dornier Model 328

– 100 and

– 300 airplanes by individual notices. This AD requires detailed visual and eddy current inspections of both the left-hand and right-hand lower wing panel of the rear trailing edge (inboard and outboard of flap lever arm 1 (rib 3 and rib 5)) for cracks, and repair if necessary. This AD is prompted by cracks found in the lower wing panel of the rear trailing edge (inboard and outboard of flap lever arm 1 (rib 5)) during a routine inspection on a Model 328

– 100 airplane. Subsequent inspection of the other Model 328

– 100 airplanes in the same fleet revealed several more airplanes with cracks at the same location. We are issuing this AD to prevent structural failure of the affected wing panel, possible separation of the wing from the airplane, and consequent loss of control of the airplane. **DATES :**  This AD becomes effective June 3, 2008 to all persons except those persons to whom it was made immediately effective by emergency AD 2008

– 10

– 51, issued May 8, 2008, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in the AD is approved by the Director of the Federal Register as of June 3, 2008.

We must receive comments on this AD by July 28, 2008. **ADDRESSES :**  You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202

– 493

– 2251.

• Mail: U.S. Department of Transportation, Docket Operations, M

– 30, West Building Ground Floor, Room W12

– 140, 1200 New Jersey Avenue, SE., Washington, DC 20590. • Hand Delivery: U.S. Department of Transportation, Docket Operations, M

– 30, West Building Ground Floor, Room W12

– 140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact 328 Support Services GmbH, P.O. Box 1252, D

– 82231 Wessling, Federal Republic of Germany. Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800

– 647

– 5527) is in the **ADDRESSES** section. Comments will be available in the AD docket shortly after receipt. **FOR FURTHER INFORMATION CONTACT :**  Mike Borfitz, Aerospace Engineer, International Branch, ANM

– 116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057

– 3356; telephone (425) 227

– 2677; fax (425) 227

– 1149. **SUPPLEMENTARY INFORMATION :**  On May 8, 2008, we issued emergency AD 2008

– 10

– 51, which applies to all Dornier Model 328

– 100 and

– 300 airplanes. Background

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, notified the FAA that an unsafe condition may exist on all Dornier Model 328

– 100 and

– 300 airplanes. The EASA advises that, during a routine inspection, cracks were found in the lower wing panel of the


### 30753 Federal Register / Vol. 73, No. 104 / Thursday, May 29, 2008 / Rules and Regulations
rear trailing edge (inboard and outboard of flap lever arm 1 (rib 5)) on a Model 328

– 100 airplane. Subsequent inspection of the other Model 328

– 100 airplanes in the same fleet revealed several more airplanes with cracks at the same location. The cause of the cracking is unknown. This condition, if not corrected, could result in structural failure of the affected wing panel, possible separation of the wing from the airplane, and consequent loss of control of the airplane. Relevant Service Information

328 Support Services GmbH has issued Dornier Alert Service Bulletins ASB

– 328J

– 57

– 015 (for Model 328

– 300 airplanes), and ASB

– 328

– 57

– 037 (for Model 328

– 100 airplanes), both Revision 1, both dated May 8, 2008. The service bulletins describe procedures for detailed visual and eddy current inspections of both the left-hand (LH) and right-hand (RH) lower wing panel of the rear trailing edge (inboard and outboard of flap lever arm 1 (rib 3 and rib 5)) for cracks. The EASA mandated the service bulletins and issued EASA emergency airworthiness directive 2008

– 0087

–E, dated May 8, 2008, to ensure the continued airworthiness of these airplanes in Europe. FAA ’ s Determination and Requirements of This AD

These airplane models are manufactured in Europe and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the EASA has kept the FAA informed of the situation described above. We have examined the EASA ’ s findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.

Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design, we issued emergency AD 2008

– 10

– 51 to prevent structural failure of the affected wing panel, possible separation of the wing from the airplane, and consequent loss of control of the airplane. The AD requires accomplishing the actions specified in the service information previously described, except as described in ‘‘ Differences Between This AD and Service Information. ’’ This AD also requires you to report the inspection results to 328 Support Services GmbH. We found that immediate corrective action was required; therefore, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on May 8, 2008, to all known U.S. owners and operators of all Dornier Model 328

– 100 and

– 300 airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons. Differences Between This AD and Service Information

The service bulletins specify to contact the manufacturer for instructions on how to repair cracks, but this AD requires repairing the cracks using a method approved by the FAA or the EASA (or its delegated agent). In light of the type of repair that is required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this AD, a repair approved by the FAA or the EASA (or its delegated agent) is acceptable for compliance with this AD.

Unlike the procedures described inthe service bulletins that specify a onetime eddy current inspection, this AD requires the eddy current inspection to be repeated at intervals not to exceed 400 flight hours. Doing the eddy current inspections terminates the detailed visual inspections required by this AD. We have determined that, because of the safety implications and consequences associated with the cracking, the eddy current inspection of the affected area must be repeated. This difference has been coordinated with the EASA. Interim Action

This AD requires that operators report the results of the inspections to 328 Support Services GmbH. Because the cause of the cracking is not known, these required inspection reports will help determine the extent of the cracking in the affected fleet. Based on the results of these reports, we may determine that further corrective action is warranted. Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the **ADDRESSES** section. Include ‘‘ Docket No. FAA

– 2008

– 0544; Directorate Identifier 2008

– NM

– 099

–AD ’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. 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.

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 AD will not have federalism implications under Executive Order 13132. This AD will 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.

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 this emergency regulation is later deemed significant under DOT Regulatory Policies and Procedures, we will prepare a final regulatory evaluation


### 30754 Federal Register / Vol. 73, No. 104 / Thursday, May 29, 2008 / Rules and Regulations
and place it in the AD Docket. See the **ADDRESSES** section for a location to examine the regulatory evaluation, if filed. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment

■ Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):
2008

– 10

– 51 328 Support Services GmbH (Formerly Avcraft Aerospace GmbH): Amendment 39

– 15535. Docket No. FAA

– 2008

– 0544; Directorate Identifier 2008

–NM

– 099

–AD. Effective Date

(a) This AD becomes effective June 3, 2008, to all persons except those persons to whom it was made immediately effective by emergency AD 2008

– 10

– 51, issued on May 8, 2008, which contained the requirements of this amendment. Affected ADs

(b) None. Applicability

(c) This AD applies all Dornier Model 328

– 100 and

– 300 airplanes, certificated in any category. Unsafe Condition

(d) This AD results from a report indicating that, during a routine inspection, cracks were found in the lower wing panel of the rear trailing edge (inboard and outboard of flap lever arm 1 (rib 5)) on a Model 328

– 100 airplane. Subsequent inspection of the other Model 328

– 100 airplanes in the same fleet revealed several more airplanes with cracks at the same location. We are issuing this AD to prevent structural failure of the affected wing panel, possible separation of the wing from the airplane, and consequent loss of control 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. Repetitive Detailed Visual Inspections for Cracks

(f) Within 10 flight cycles, or 10 flight hours, or 7 days, whichever occurs first, after the effective date of this AD: Accomplish adetailed visual inspection of both the lefthand (LH) and right-hand (RH) lower wing panel inboard and outboard of flap lever arm 1 (rib 5) for cracks, in accordance with the Accomplishment Instructions of Dornier Alert Service Bulletin ASB

– 328J

– 57

– 015, or ASB

– 328

– 57

– 037, both Revision 1, both dated May 8, 2008, as applicable. If no crack is detected, repeat the detailed visual inspection thereafter at intervals not to exceed 50 flight hours until the eddy current inspection required by paragraph (g) of this AD is accomplished. If any crack is detected, before further flight, do an eddy current inspection in accordance with paragraph (g) of this AD. Repetitive Eddy Current Inspections for Cracks

(g) Within 400 flight hours or 3 months after the effective date of this AD, whichever occurs first: Accomplish an eddy current inspection of both the LH and RH lower wing panel in the vicinity of rib 3 and inboard and outboard of flap lever arm 1 (rib 5) for cracks, in accordance with the Accomplishment Instructions of Dornier Alert Service Bulletin ASB

– 328J

– 57

– 015, or ASB

– 328

– 57

– 037, both Revision 1, both dated May 8, 2008, as applicable. Repeat the eddy current inspection thereafter at intervals not to exceed 400 flight hours. Accomplishment of the eddy current inspection terminates the detailed visual inspection required by paragraph (f) of this AD. Repair

(h) If any crack is detected during any inspection required by this AD: Before further flight, repair the crack using a method approved by either the Manager, International Branch, ANM

– 116, Transport Airplane Directorate, FAA; or the European Aviation Safety Agency (or its delegated agent). Credit for Previously Accomplished Actions

(i) Accomplishment of the actions required by paragraph (f) or (g) of this AD before the effective date of this AD in accordance with Dornier Alert Service Bulletin ASB

– 328J

– 57

– 015 or ASB

– 328

– 57

– 037, both dated May 5, 2008, as applicable, is considered acceptable for compliance with the corresponding initial inspection requirements specified in paragraph (f) or (g) of this AD. Report

(j) At the applicable time specified in paragraph (j)(1) or (j)(2) of this AD: Send 328 Support Services GmbH a report of findings (both positive and negative) found during each inspection required by paragraphs (f) and (g) of this AD. The report must include the inspection results, a description of any cracks found, the airplane serial number, and the number of landings and flight hours on the airplane. Send the report to 328 Support Services GmbH, Global Support Center, P.O. Box 1252, D

– 82231 Wessling, Federal Republic of Germany; Telephone +49 8153 88111 6666; fax 49 8153 88111 6565; E-mail: gsc.op@328support.de. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120

– 0056.

(1) For any inspection done after the effective date of this AD: Within 3 days after the inspection.

(2) For any inspection done before the effective date of this AD: Within 3 days after the effective date of this AD. Special Flight Permits

(k) 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 done if the following conditions are met:

(1) The initial inspection required by paragraph (f) of this AD must be accomplished.

(2) If a crack indication exceeds 12.5 mm (0.49 inch), the Manager, International Branch, ANM

– 116, concurs with issuance of the special flight permits. Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, International Branch, ANM

– 116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. Related Information

(m) European Aviation Safety Agency emergency airworthiness directive 2008

– 0087

–E, dated May 8, 2008, also addresses the subject of this AD. Material Incorporated by Reference

(n) You must use Dornier Alert Service Bulletin ASB

– 328J

– 57

– 015, Revision 1, dated May 8, 2008; or Dornier Alert Service Bulletin ASB

– 328

– 57

– 037, Revision 1, dated May 8, 2008; as applicable; to perform the actions that are required by this AD, unlessthe AD specifies otherwise. (Only the oddnumbered pages of the documents contain the document revision level and issue date; the even-numbered pages do not contain this information.) The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get copies of the service information, contact 328 Support Services GmbH, P.O. Box 1252, D

– 82231 Wessling, Germany. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202

– 741

– 6030, or go to: http://www.archives.gov/federal-register/ cfr/ibr-locations.html.


### 30755 Federal Register / Vol. 73, No. 104 / Thursday, May 29, 2008 / Rules and Regulations
Issued in Renton, Washington, on May 14, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8

– 11468 Filed 5

– 28

– 08; 8:45 am] **BILLING CODE 4910**

**– 13** 

**– P** 

**DEPARTMENT OF TRANSPORTATION Federal Aviation Administration** 
**14 CFR Part 39 [Docket No. FAA** 

**– 2007** 

**– 28598; Directorate**  **Identifier 2007**

**– NM** 

**– 036** 

**– AD; Amendment**  **39**

**– 15529; AD 2008** 

**– 11** 

**– 07]**  **RIN 2120**

**– AA64**  **Airworthiness Directives; Boeing Model 757 Airplanes** 
**AGENCY :**  Federal Aviation Administration (FAA), DOT. **ACTION :**  Final rule.
**SUMMARY :**  We are adopting a new airworthiness directive (AD) for all Boeing Model 757 airplanes. This AD requires installation of an automatic shutoff system for the center tank fuel boost pumps, and installation of a placard in the airplane flight deck if necessary. This AD also requires revisions to the Limitations and Normal Procedures sections of the airplane flight manual to advise the flightcrew of certain operating restrictions for airplanes equipped with an automated center tank fuel pump shutoff control. This AD also requires a revision to the Airworthiness Limitations (AWLs) section of the Instructions for Continued Airworthiness to incorporate AWLs No. 28

–AWL

– 20 and No. 28

–AWL

– 26. This AD also requires replacement of the fuel control panel assembly with a modified part, installation of two secondary pump control relays for the center tank fuel pumps, other specified actions, and concurrent modification of the fuel control panel assembly. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent center tank fuel pump operation with continuous low pressure, which could lead to friction sparks or overheating in the fuel pump inlet that could create a potential ignition source inside the center fuel tank; these conditions, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane. **DATES :**  This AD is effective July 3, 2008.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of July 3, 2008. **ADDRESSES :**  For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124

– 2207. Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone 800

– 647

– 5527) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M

– 30, West Building Ground Floor, Room W12

– 140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
**FOR FURTHER INFORMATION CONTACT :**  Judy Coyle, Aerospace Engineer, Propulsion Branch, ANM

– 140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057

– 3356; telephone (425) 917

– 6497; fax (425) 917

– 6590. **SUPPLEMENTARY INFORMATION :**  Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to all Boeing Model 757

– 200,

– 200CB,

– 200PF, and

– 300 series airplanes. That NPRM was published in the Federal Register on July 9, 2007 (72 FR 37132). That NPRM proposed to require installation of an automatic shutoff system for the center tank fuel boost pumps, and installation of a placard in the airplane flight deck if necessary. That NPRM also proposed to require revisions to the Limitations and Normal Procedures sections of the airplane flight manual to advise the flightcrew of certain operating restrictions for airplanes equipped with an automated center tank fuel pump shutoff control. That NPRM also proposed to require a revision to the Airworthiness Limitations (AWLs) section of the Instructions for Continued Airworthiness (ICA) to incorporate AWLs No. 28

–AWL

– 20 and No. 28

– AWL

– 26. That NPRM also proposed to require replacement of the fuel control panel assembly with a modified part, installation of two secondary pump control relays for the center tank fuel pumps, other specified actions, and concurrent modification of the fuel control panel assembly. Actions Since NPRM Was Issued On April 29, 2008, we issued AD 2008

– 10

– 11, amendment 39

– 15517, that applies to all Model 757 airplanes. AD 2008

– 10

– 11, among other actions, requires revising the AWLs section of the ICA by incorporating AWLs No. 28

– AWL

– 01 through No. 28

–AWL

– 24 of Section 9 of the Boeing 757 Maintenance Planning Document (MPD) Document D622N001

– 9, Revision March 2008. AD 2008

– 10

– 11 also provides the optional action of incorporating AWL No. 28

–AWL

– 26. This AD, however, requires the incorporation of AWLs No. 28

–AWL

– 20 and No. 28

–AWL

– 26 in accordance with paragraphs (j) and (m) of this AD, respectively. Therefore, we have added a new paragraph (q) to this AD specifying that incorporating AWLs No. 28

–AWL

– 20 and No. 28

–AWL

– 26 into the AWLs section of the ICA in accordance with paragraph (g)(3) of AD 2008

– 10

– 11 terminates the corresponding actions required by this AD. Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from the four commenters. Request To Revise the Unsafe Condition

Boeing requests that we clarify the unsafe condition in the summary and in paragraph (d) of the NPRM. Boeing states that the unsafe condition exists when continuous low pressure is indicated during pump operation with no fuel available to cover the pump inlet, and that it does not exist when there is fuel available to cover the pump inlet during pump operation. Boeing suggests using the following statement:

We are issuing this AD to prevent center tank fuel pump operation with continuous low pressure (with no fuel passing through the pump), which could lead to friction sparks or overheating in the fuel pump inlet that could create a potential ignition source inside the center fuel tank. These conditions, in combination with flammable fuel vapors, could result in a center fuel tank explosion and consequent loss of the airplane.

We agree that the unsafe condition is present only when there is no fuel available to cover the pump inlet. When fuel is not covering the pump inlet, the

‘‘ continuous low pressure ’’ indication will be present. Therefore, we have not added the phrase ‘‘ with no fuel passing through the pump ’’ to this AD in this regard, since the continuous low pressure indication is integral to describing the unsafe condition. We have, however, revised the summary and paragraph (d) of this AD by