Federal Register / Vol. 73, No. 153 / Thursday, August 7, 2008 / Proposed Rules 45893 

a manufacturer or other source, use these 

actions if they are FAA-approved. Corrective 

actions are considered FAA-approved if they 

are approved by the State of Design Authority 

(or their delegated agent). You are required 

to assure the product is airworthy before it 

is returned to service. 

(3) Reporting Requirements: For any 

reporting requirement in this AD, under the 

provisions of the Paperwork Reduction Act, 

the Office of Management and Budget (OMB) 

has approved the information collection 

requirements and has assigned OMB Control 

Number 2120–0056. 

Related Information 

(h) Refer to MCAI EASA Airworthiness 

Directive 2008–0066, dated March 31, 2008, 

and Airbus Service Bulletins A310–54–2032, 

Revision 01, dated October 8, 2007; and 

A310–54–2036, Revision 02, dated 

September 28, 2007; for related information. 

Issued in Renton, Washington, on July 29, 

2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E8–18210 Filed 8–6–08; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0847; Directorate 

Identifier 2008–NM–056–AD] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 777 Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

Boeing Model 777 airplanes. This 

proposed AD would require doing an 

inspection of the motor operated valve 

(MOV) actuators of the main and center 

fuel tanks for a certain part number; 

replacing the MOV actuator with a new 

MOV actuator if necessary; and 

measuring the electrical resistance of 

the bond from the adapter plate to the 

airplane structure, and corrective 

actions if necessary. This proposed AD 

would also require revising the 

Airworthiness Limitations section of the 

Instructions for Continued 

Airworthiness. This proposed AD 

results from fuel system reviews 

conducted by the manufacturer. We are 

proposing this AD to prevent electrical 

current from flowing through a MOV 

actuator into a fuel tank, which could 

create a potential ignition source inside 

the fuel tank. This condition, in 

combination with flammable fuel 

vapors, could result in a fuel tank 

explosion and consequent loss of the 

airplane. 

DATES: We must receive comments on 

this proposed AD by September 22, 

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 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 proposed 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: 

Margaret Langsted, Aerospace Engineer, 

Propulsion Branch, ANM–140S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6500; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposed AD. Send your comments 

to an address listed under the 

ADDRESSES section. Include ‘‘Docket No. 

FAA–2008–0847; Directorate Identifier 

2008–NM–056–AD’’ at the beginning of 

your comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of this proposed AD. We will 

consider all comments received by the 

closing date and may amend this 

proposed 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 proposed AD. 

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 

Review, Flammability Reduction and 

Maintenance and Inspection 

Requirements’’ (66 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 


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45894 Federal Register / Vol. 73, No. 153 / Thursday, August 7, 2008 / Proposed Rules 

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. 

Boeing has found that, under specific 

conditions, it is possible for electrical 

current to flow through a motor 

operated valve (MOV) actuator into a 

fuel tank, which could create a potential 

ignition source inside the fuel tank. This 

condition, if not corrected, in 

combination with flammable fuel 

vapors, could result in a fuel tank 

explosion and consequent loss of the 

airplane. 

Other Related Rulemaking 

On May 14, 2008, we issued AD 

2008–11–13, amendment 39–15536 (73 

FR 30737, May 29, 2008), applicable to 

certain Boeing Model 777–200, –200LR, 

–300, and –300ER series airplanes. That 

AD requires revising the Airworthiness 

Limitations (AWLs) section of the 

Instructions for Continued 

Airworthiness (ICA) by incorporating 

new limitations for fuel tank systems to 

satisfy SFAR 88 requirements. That AD 

also requires the initial performance of 

certain repetitive inspections specified 

in the AWLs to phase in those 

inspections, and repair if necessary. 

That AD resulted from a design review 

of the fuel tank systems. We issued that 

AD to prevent the potential for ignition 

sources inside fuel tanks caused by 

latent failures, alterations, repairs, or 

maintenance actions, which, in 

combination with flammable fuel 

vapors, could result in fuel tank 

explosions and consequent loss of the 

airplane. Incorporating AWL No. 28–

AWL–19 and No. 28–AWL–20 into the 

AWLs section of the ICA in accordance 

with paragraph (g)(2) of AD 2008–11–

13, terminates the action required by 

paragraph (h) of this AD. 

Relevant Service Information 

We have reviewed Boeing Alert 

Service Bulletin 777–28A0034, dated 

August 2, 2007. The service bulletin 

describes procedures for doing an 

inspection of the MOV actuators of the 

main and center fuel tanks for a certain 

part number; replacing the MOV 

actuator with a new MOV actuator if 

necessary; and measuring the electrical 

resistance of the bond from the adapter 

plate to the airplane structure, and 

corrective actions if necessary. The 

corrective actions include reworking the 

bracket, cleaning and refinishing the 

bracket area, removing and reworking 

the index plate, and electrically bonding 

and installing the index plate. 

We have also reviewed Section 9, 

Revision 28, dated February 2006, of 

Boeing 777 Maintenance Planning Data 

(MPD) Document, D622W001–9 

(hereafter referred to as ‘‘Boeing 777 

MPD’’). Subsection E of Section 9 of the 

Boeing 777 MPD adds new AWLs No. 

28–AWL–19 and No. 28–AWL–20, 

which are critical design configuration 

control limitations (CDCCLs) to address 

inspection and repair of the MOV 

actuators. 

FAA’s Determination and Requirements 

of this Proposed AD 

We are proposing this AD because we 

evaluated all relevant information and 

determined the unsafe condition 

described previously is likely to exist or 

develop in other products of the(se) 

same type design(s). This proposed AD 

would require accomplishing the 

actions specified in the service 

information described previously. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 197 airplanes of U.S. 

registry. We also estimate that it would 

take about 352 or 452 work-hours per 

product to comply with this proposed 

AD, depending on the product 

configuration. The average labor rate is 

$80 per work-hour. Based on these 

figures, we estimate the cost of this 

proposed AD to the U.S. operators to be 

$5,547,520 to $7,123,520, or $28,160 to 

$36,160 per product, depending on the 

product configuration. 

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 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 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. 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. 

You can find our regulatory 

evaluation and the estimated costs of 

compliance in the AD Docket. 

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 

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 AD: 

Boeing: Docket No. FAA–2008–0847; 

Directorate Identifier 2008–NM–056–AD. 

Comments Due Date 

(a) We must receive comments by 

September 22, 2008. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to Boeing Model 777–

200, –200LR, –300, and –300ER series 

airplanes, certificated in any category; as 

identified in Boeing Alert Service Bulletin 

777–28A0034, dated August 2, 2007. 

Note 1: This AD requires revisions to 

certain operator maintenance documents to 

include new inspections. Compliance with 

these inspections is required by 14 CFR 

91.403(c). For airplanes that have been 

previously modified, altered, or repaired in 

the areas addressed by these inspections, the 

operator may not be able to accomplish the 


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Federal Register / Vol. 73, No. 153 / Thursday, August 7, 2008 / Proposed Rules 45895 

inspections described in the revisions. In this 

situation, to comply with 14 CFR 91.403(c), 

the operator must request approval for an 

alternative method of compliance (AMOC) 

according to paragraph (k) of this AD. The 

request should include a description of 

changes to the required inspections that will 

ensure the continued operational safety of 

the airplane. 

Unsafe Condition 

(d) This AD results from fuel system 

reviews conducted by the manufacturer. We 

are issuing this AD to prevent electrical 

current from flowing through a motor 

operated valve (MOV) actuator into a fuel 

tank, which could create a potential ignition 

source inside the fuel tank. This condition, 

in combination with flammable fuel vapors, 

could result in a fuel tank explosion and 

consequent loss of the airplane. 

Compliance 

(e) Comply with this AD within the 

compliance times specified, unless already 

done. 

Inspection 

(f) Within 60 months after the effective 

date of this AD, do an inspection of the MOV 

actuators of the main and center fuel tanks 

for part number MA20A1001–1, in 

accordance with the Accomplishment 

Instructions of Boeing Alert Service Bulletin 

777–28A0034, dated August 2, 2007. 

Replacement 

(g) If any part number MA20A1001–1 is 

found during the inspection required by 

paragraph (f) of this AD, within 60 months 

after the effective date of this AD, do the 

actions specified in paragraphs (g)(1) and 

(g)(2) of this AD by accomplishing all the 

applicable actions specified in the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 777–28A0034, dated August 

2, 2007. Do all applicable corrective actions 

before further flight. 

(1) Replace the MOV actuator with a new 

MOV actuator, part number MA030A1001. 

(2) Measure the electrical resistance of the 

bond from the adapter plate to the airplane 

structure, and do all applicable corrective 

actions. 

Airworthiness Limitations (AWLs): Revision 

for AWL No. 28–AWL–19 and 28–AWL–20 

(h) Concurrently with accomplishing the 

actions required by paragraph (g) of this AD, 

revise the AWLs section of the Instructions 

for Continued Airworthiness (ICA) by 

incorporating AWL No. 28–AWL–19 and No. 

28–AWL–20 of Subsection E of Section 9, 

Revision 28, dated February 2006, of the 

Boeing 777 Maintenance Planning Data 

(MPD) Document, D622W001–9. 

No Alternative Critical Design Configuration 

Control Limitations (CDCCLs) 

(i) After accomplishing the action specified 

in paragraph (h) of this AD, no alternative 

CDCCLs may be used unless the CDCCLs are 

approved as an AMOC in accordance with 

the procedures specified in paragraph (k) of 

this AD. 

Terminating Action for AWLs Revision 

(j) Incorporating AWL No. 28–AWL–19 and 

No. 28–AWL–20 into the AWLs section of the 

ICA in accordance with paragraph (g)(2) of 

AD 2008–11–13, amendment 39–15536, 

terminates the action required by paragraph 

(h) of this AD. 

Alternative Methods of Compliance 

(AMOCs) 

(k)(1) The Manager, Seattle ACO, FAA, 

ATTN: Margaret Langsted, Aerospace 

Engineer, Propulsion Branch, ANM–140S, 

FAA, SACO, 1601 Lind Avenue, SW., 

Renton, Washington 98057–3356; telephone 

(425) 917–6500; fax (425) 917–6590; has the 

authority to approve AMOCs for this AD, if 

requested using 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. 

Issued in Renton, Washington, on July 29, 

2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E8–18211 Filed 8–6–08; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0846; Directorate 

Identifier 2008–NM–045–AD] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 757–200, 757–200PF, and 757–

300 Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

Boeing Model 757–200, 757–200PF, and 

757–300 series airplanes. This proposed 

AD would require, for certain airplanes, 

measuring the electrical bond resistance 

at certain stations and doing any 

applicable repair; installing support 

brackets for the hot short protector and 

new support clamps for the wire 

bundles; installing the equipment of the 

hot short protector; and modifying an 

existing wire bundle and installing a 

new wire bundle. This proposed AD 

would also require, for certain other 

airplanes, measuring the electrical bond 

resistance at certain stations, measuring 

the electrical bonding resistance 

between the hot short protector and rear 

spar web, and doing any applicable 

repair. This proposed AD also would 

require revising the Airworthiness 

Limitations section of the Instructions 

for Continued Airworthiness. This 

proposed AD results from fuel system 

reviews conducted by the manufacturer. 

We are proposing this AD to prevent the 

center fuel tank densitometer from 

overheating and becoming a potential 

ignition source inside the fuel tank, 

which, in combination with flammable 

fuel vapors, could result in a center fuel 

tank explosion and consequent loss of 

the airplane. 

DATES: We must receive comments on 

this proposed AD by September 22, 

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 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 proposed 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: Jen 

Pei, Aerospace Engineer, Systems and 

Equipment Branch, ANM–130S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6409; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 


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