Federal Register / Vol. 73, No. 78 / Tuesday, April 22, 2008 / Rules and Regulations 21523 

Follow-On Actions for Category A, B, C, or 

D Trunnion Fork Assemblies 

(h) If any part number and serial number 

identified as Category A, B, C, or D in Tables 

2 and 3 of paragraph 1.E., ‘‘Compliance,’’ of 

the service bulletin is found installed during 

the inspection required by paragraph (g) of 

this AD: At the applicable compliance time(s) 

listed in Table 4 or 5 of paragraph 1.E., 

‘‘Compliance,’’ of the service bulletin, except 

as provided by paragraph (i) of this AD, do 

the applicable action(s) in Table 1 of this AD 

and applicable related investigative/ 

corrective actions, in accordance with the 

Accomplishment Instructions of the service 

bulletin. 

TABLE 1.—REQUIREMENTS FOR CATEGORY A, B, C, OR D TRUNNION FORK ASSEMBLIES

For— Do— And— Or— 

(1) Categories A and C trunnion 

fork assemblies.

A detailed inspection for damage 

to the protective finish and for 

corrosion of the trunnion fork 

assembly and a high frequency 

eddy current (HFEC) inspection 

to detect cracks (Part 2).

An ultrasonic inspection to determine the wall thickness in the 

area forward of the outer cylinder attach lugs in 8 zones, 

and a hardness measurement if 

applicable (Part 3).

Do the terminating action (Part 5). 

(2) Categories B and D trunnion 

fork assemblies.

An ultrasonic inspection to determine the wall thickness in the 

area forward of the outer cylinder attach lugs in 8 zones, 

and a hardness measurement 

(Part 3).

None ............................................. None. 

(i) Where paragraph 1.E., ‘‘Compliance,’’ of 

the service bulletin specifies a compliance 

time after the date on the service bulletin, 

this AD requires compliance within the 

specified compliance time after the effective 

date of this AD. 

Terminating Action 

(j) Replacing the trunnion fork assembly of 

the wing landing gear with a trunnion fork 

assembly identified in Part 5 of the 

Accomplishment Instructions of the service 

bulletin, in accordance with and at the 

applicable time specified in Table 4 or 5 of 

paragraph 1.E., ‘‘Compliance,’’ of the service 

bulletin, constitutes terminating action for 

the requirements of this AD for that side 

only. 

Alternative Methods of Compliance 

(AMOCs) 

(k)(1) The Manager, Seattle Aircraft 

Certification Office (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) 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. 

Material Incorporated by Reference 

(l) You must use Boeing Alert Service 

Bulletin 747–32A2482, dated June 14, 2007, 

to do the actions required by this AD, unless 

the AD specifies otherwise. 

(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 Boeing Commercial 

Airplanes, P.O. Box 3707, Seattle, 

Washington 98124–2207. 

(3) You may review copies of the service 

information incorporated by reference 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/ 

code_of_federal_regulations/ 

ibr_locations.html. 

Issued in Renton, Washington, on April 14, 

2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E8–8530 Filed 4–21–08; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0031; Directorate 

Identifier 2007–NM–313–AD; Amendment 

39–15484; AD 2008–09–04] 

RIN 2120–AA64 

Airworthiness Directives; McDonnell 

Douglas Model DC–8–31, DC–8–32, 

DC–8–33, DC–8–41, DC–8–42, and DC–

8–43 Airplanes; Model DC–8–50 Series 

Airplanes; Model DC–8F–54 and DC–

8F–55 Airplanes; Model DC–8–60 

Series Airplanes; Model DC–8–60F 

Series Airplanes; Model DC–8–70 

Series Airplanes; and Model DC–8–70F 

Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for all 

McDonnell Douglas airplanes identified 

above. This AD requires revising the 

FAA-approved maintenance program to 

incorporate new airworthiness 

limitations for fuel tank systems to 

satisfy Special Federal Aviation 

Regulation No. 88 requirements. This 

AD results from a design review of the 

fuel tank systems. We are issuing this 

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 a fuel tank 

explosion and consequent loss of the 

airplane. 

DATES: This AD is effective May 27, 

2008. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of May 27, 2008. 

ADDRESSES: For service information 

identified in this AD, contact Boeing 

Commercial Airplanes, Long Beach 

Division, 3855 Lakewood Boulevard, 

Long Beach, California 90846, Attention: 

Data and Service Management, Dept. 

C1–L5A (D800–0024). 

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, 


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21524 Federal Register / Vol. 73, No. 78 / Tuesday, April 22, 2008 / Rules and Regulations 

1200 New Jersey Avenue, SE., 

Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: 

Samuel Lee, Aerospace Engineer, 

Propulsion Branch, ANM–140L, FAA, 

Los Angeles Aircraft Certification 

Office, 3960 Paramount Boulevard, 

Lakewood, California 90712–4137; 

telephone (562) 627–5262; fax (562) 

627–5210. 

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 

McDonnell Douglas Model DC–8–31, 

DC–8–32, DC–8–33, DC–8–41, DC–8–42, 

and DC–8–43 airplanes; Model DC–8–50 

series airplanes; Model DC–8F–54 and 

DC–8F–55 airplanes; Model DC–8–60 

series airplanes; Model DC–8–60F series 

airplanes; Model DC–8–70 series 

airplanes; and Model DC–8–70F series 

airplanes. That NPRM was published in 

the Federal Register on January 18, 

2008 (73 FR 3419). That NPRM 

proposed to require revising the FAAapproved maintenance program to 

incorporate new airworthiness 

limitations for fuel tank systems to 

satisfy Special Federal Aviation 

Regulation No. 88 requirements. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. We 

considered the comments received from 

the one commenter, Boeing. 

Changes Made to This AD 

For standardization purposes, we 

have revised this AD in the following 

ways: 

• We have added a new paragraph (h) 

to this AD to specify that no alternative 

inspections, inspection intervals, or 

critical design configuration control 

limitations (CDCCLs) may be used 

unless they are part of a later approved 

revision of the Boeing DC–8 Special 

Compliance Item Report, MDC–

02K9030, Revision A, dated August 8, 

2006 (hereafter referred to as ‘‘Report 

MDC–02K9030’’), or unless they are 

approved as an alternative method of 

compliance (AMOC). Inclusion of this 

paragraph in the AD is intended to 

ensure that the AD-mandated 

airworthiness limitations changes are 

treated the same as the airworthiness 

limitations issued with the original type 

certificate. We have renumbered the 

subsequent paragraphs accordingly. 

• We have simplified the language in 

Note 1 of this AD to clarify that an 

operator must request approval for an 

AMOC if the operator cannot 

accomplish the required inspections 

because an airplane has been previously 

modified, altered, or repaired in the 

areas addressed by the required 

inspections. 

Request To Revise Note 1 

Boeing requests that we revise Note 1 

of the NPRM to clarify that deviations 

from the AWLs specified in Report 

MDC–02K9030, should be approved as 

an AMOC according to paragraph (h) of 

the NPRM. Boeing states that Note 1 of 

the NPRM might be interpreted to mean 

that the Airworthiness Limitations 

(AWLs) specified in Report MDC–

02K9030 must be revised to reflect 

modifications, alterations, or repairs 

that are initiated by an operator and 

outside of Boeing’s design cognizance 

and responsibility. Boeing requests that 

we revise Note 1 as follows: 

• Replace the words ‘‘revision to’’

with ‘‘deviation from’’ in the last 

sentence. 

• Delete the words ‘‘(f), or’’ and ‘‘as 

applicable’’ from the last sentence. 

As stated previously, we have 

simplified the language in Note 1 of this 

AD for standardization with other 

similar ADs. The language the 

commenter requests we change does not 

appear in the revised note; therefore, no 

additional change to this AD is 

necessary in this regard. 

Request To Clarify Approval of 

Component Maintenance Manual 

(CMM) Changes 

Boeing requests that we revise the 

heading and certain wording for the 

‘‘Changes to Component Maintenance 

Manuals (CMMs) Cited in Fuel Tank 

System AWLs’’ section of the NPRM. 

Boeing believes that section was 

intended to address situations where an 

operator chooses to deviate from the 

procedures in the CMM referenced in 

Report MDC–02K9030. Boeing states 

that its proposed changes are intended 

to clarify that only deviations proposed 

by an operator require approval of the 

Manager, Los Angeles Aircraft 

Certification Office, FAA. Boeing further 

states that wording in the NPRM could 

be interpreted to mean that approval of 

a CMM in its entirety, including any 

future CMM revisions by Boeing, would 

require direct approval of the Manager, 

Los Angeles, ACO, or governing 

regulatory authority. Specifically, 

Boeing requests that we revise that 

section as follows: 

• Revise the heading to ‘‘Deviations 

from Component Maintenance Manuals 

(CMMs) Cited in Fuel Tank System 

AWLs.’’

• Revise the third sentence to state 

that the Manager, Los Angeles ACO, 

must approve ‘‘any deviations from’’ the 

CMMs ‘‘as defined in Report MDC–

02K9030.’’

• Replace the words ‘‘revision of’’

with ‘‘deviation from’’ in the fourth 

sentence. 

• Revise the fourth sentence to state 

that those CMMs ‘‘as defined in Report 

MDC–02K9030’’ will be handled like a 

change to the AWL itself. 

• Delete the entire last sentence. 

We agree that clarification is 

necessary. Our intent is that any 

deviation from the CMMs as defined in 

Report MDC–02K9030 must be 

approved by the Manager, Los Angeles 

ACO, or the governing regulatory 

authority, before those deviations can be 

used. However, we have not changed 

the AD as suggested by the commenter, 

since the ‘‘Changes to Component 

Maintenance Manuals (CMMs) Cited in 

Fuel Tank System AWLs’’ section of the 

NPRM is not retained in this final rule. 

Conclusion 

We reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting the AD 

as proposed with the changes described 

previously. We also determined that 

these changes will not increase the 

economic burden on any operator or 

increase the scope of the AD. 

Costs of Compliance 

We estimate that this AD affects 125 

airplanes of U.S. registry. We also 

estimate that it takes about 1 work-hour 

per product to comply with this AD. 

The average labor rate is $80 per workhour. Based on these figures, we 

estimate the cost of this AD to U.S. 

operators to be $10,000, or $80 per 

product. 

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 


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Federal Register / Vol. 73, No. 78 / Tuesday, April 22, 2008 / Rules and Regulations 21525 

products identified in this rulemaking 

action. 

Regulatory Findings 

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. 

For the reasons discussed above, I 

certify that this AD: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

(2) Is not a ‘‘significant rule’’ under 

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, 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 AD: 

2008–09–04 McDonnell Douglas: 

Amendment 39–15484. Docket No. 

FAA–2008–0031; Directorate Identifier 

2007–NM–313–AD. 

Effective Date 

(a) This airworthiness directive (AD) is 

effective May 27, 2008. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to all McDonnell 

Douglas Model DC–8–31, DC–8–32, DC–8–

33, DC–8–41, DC–8–42, and DC–8–43 

airplanes; Model DC–8–51, DC–8–52, DC–8–

53, and DC–8–55 airplanes; Model DC–8F–54 

and DC–8F–55 airplanes; Model DC–8–61, 

DC–8–62, and DC–8–63 airplanes; Model 

DC–8–61F, DC–8–62F, and DC–8–63F 

airplanes; Model DC–8–71, DC–8–72, and 

DC–8–73 airplanes; and Model DC–8–71F, 

DC–8–72F, and DC–8–73F airplanes; 

certificated in any category. 

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 

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) in 

accordance with paragraph (i) 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 a design review 

of the fuel tank systems. We are issuing this 

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 a fuel 

tank explosion and consequent loss of the 

airplane. 

Compliance 

(e) Comply with this AD within the 

compliance times specified, unless already 

done. 

Revise the FAA-Approved Maintenance 

Program 

(f) Before December 16, 2008, revise the 

FAA-approved maintenance program to 

incorporate the information specified in 

Appendixes B, C, and D of the Boeing DC–

8 Special Compliance Item Report, MDC–

02K9030, Revision A, dated August 8, 2006. 

Accomplishing the revision in accordance 

with a later revision of the Boeing DC–8 

Special Compliance Item Report, MDC–

02K9030, is an acceptable method of 

compliance if the revision is approved by the 

Manager, Los Angeles Aircraft Certification 

Office (ACO), FAA. 

No Reporting Requirement 

(g) Although the Boeing DC–8 Special 

Compliance Item Report, MDC–02K9030, 

Revision A, dated August 8, 2006, specifies 

to submit certain information to the 

manufacturer, this AD does not require that 

action. 

No Alternative Inspections, Inspection 

Intervals, or Critical Design Configuration 

Control Limitations (CDCCLs) 

(h) After accomplishing the applicable 

actions specified in paragraph (f) of this AD, 

no alternative inspections, inspection 

intervals, or CDCCLs may be used unless the 

inspections, intervals, or CDCCLs are part of 

a later revision of Boeing DC–8 Special 

Compliance Item Report, MDC–02K9030, 

Revision A, dated August 8, 2006, that is 

approved by the Manager, Los Angeles ACO; 

or unless the inspections, intervals, or 

CDCCLs are approved as an AMOC in 

accordance with the procedures specified in 

paragraph (i) of this AD. 

AMOCs 

(i)(1) The Manager, Los Angeles ACO, 

FAA, ATTN: Samuel Lee, Aerospace 

Engineer, Propulsion Branch, ANM–140L, 

3960 Paramount Boulevard, Lakewood, 

California 90712–4137; telephone (562) 627–

5262; fax (562) 627–5210; 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. 

Material Incorporated by Reference 

(j) You must use Boeing DC–8 Special 

Compliance Item Report, MDC–02K9030, 

Revision A, dated August 8, 2006, to do the 

actions required by this AD, unless the AD 

specifies otherwise. (The revision date for 

this document is identified only on the title 

page and in the ‘‘Index of Page Changes’’

section of the document.) This document 

contains the following effective pages: 

Pages Revision Date 

Index of Page Changes Pages i through iii ...................................................................................................... A .................. August 8, 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 Boeing Commercial 

Airplanes, Long Beach Division, 3855 

Lakewood Boulevard, Long Beach, California 

90846, Attention: Data and Service 

Management, Dept. C1–L5A (D800–0024). 

(3) You may review copies of the service 

information incorporated by reference 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/ 

code_of_federal_regulations/ 

ibr_locations.html. 


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21526 Federal Register / Vol. 73, No. 78 / Tuesday, April 22, 2008 / Rules and Regulations 

Issued in Renton, Washington, on April 4, 

2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E8–8532 Filed 4–21–08; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0410; Directorate 

Identifier 2007–NM–362–AD; Amendment 

39–15485; AD 2006–12–10 R1] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 747–400 Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule; request for 

comments. 

SUMMARY: The FAA is revising an 

existing airworthiness directive (AD) 

that applies to certain Boeing Model 

747–400 series airplanes. That AD 

currently requires inspecting the 

support bracket of the crew oxygen 

cylinder installation to determine the 

manufacturing date marked on the 

support, and performing corrective 

action if necessary. This new AD retains 

all the requirements of the existing AD 

and expands the applicability of the 

existing AD to include certain airplanes 

that are not on the U.S. Register. This 

AD results from a report indicating that 

certain oxygen cylinder supports may 

not have been properly heat-treated. We 

are issuing this AD to prevent failure of 

the oxygen cylinder support under the 

most critical flight load conditions, 

which could cause the oxygen cylinder 

to come loose and leak oxygen. Leakage 

of oxygen could result in oxygen being 

unavailable for the flightcrew or could 

result in a fire hazard in the vicinity of 

the leakage. 

DATES: Effective May 7, 2008. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in the AD 

as of May 7, 2008. 

On July 17, 2006 (71 FR 33604, June 

12, 2006), the Director of the Federal 

Register approved the incorporation by 

reference of Boeing Special Attention 

Service Bulletin 747–35–2114, dated 

December 19, 2002. 

We must receive comments on this 

AD by June 23, 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 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: 

Robert Hettman, Aerospace Engineer, 

Cabin Safety and Environmental 

Systems Branch, ANM–150S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6457; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Discussion 

On May 31, 2006, we issued AD 

2006–12–10, amendment 39–14635 (71 

FR 33604, June 12, 2006), for certain 

Boeing Model 747–400 series airplanes 

(i.e., those identified in Boeing Special 

Attention Service Bulletin 747–35–

2114, dated December 19, 2002). That 

AD requires inspecting the support 

bracket of the crew oxygen cylinder 

installation to determine the 

manufacturing date marked on the 

support, and performing corrective 

action if necessary. That AD resulted 

from a report indicating that certain 

oxygen cylinder supports may not have 

been properly heat-treated. We issued 

that AD to prevent failure of the oxygen 

cylinder support under the most critical 

flight load conditions, which could 

cause the oxygen cylinder to come loose 

and leak oxygen. Leakage of oxygen 

could result in oxygen being unavailable 

for the flightcrew or could result in a 

fire hazard in the vicinity of the leakage. 

Actions Since Existing AD Was Issued 

Since we issued AD 2006–12–10, 

Boeing issued Special Attention Service 

Bulletin 747–35–2114, Revision 1, dated 

June 7, 2007, to add airplanes to the 

effectivity of the service bulletin. With 

the exception of the added airplanes, 

the actions specified in Revision 1 are 

the same as those specified in Boeing 

Special Attention Service Bulletin 747–

35–2114, dated December 19, 2002 

(referenced as a source of service and 

applicability information in AD 2006–

12–10). 

FAA’s Determination and Requirements 

of This AD 

The unsafe condition described 

previously is likely to exist or develop 

on other airplanes of the same type 

design. For this reason, we are issuing 

this AD to revise AD 2006–12–10. This 

new AD retains the requirements of the 

existing AD. This AD also adds new 

airplanes to the applicability. 

Costs of Compliance 

No airplane added to the applicability 

of this AD is currently on the U.S. 

Register. However, if any affected 

airplane is imported and placed on the 

U.S. Register in the future, it will be 

subject to the per-airplane cost specified 

below. 

There are about 83 airplanes of the 

affected design in the worldwide fleet. 

This AD affects about 15 airplanes of 

U.S. registry. The required inspection 

will take about 1 work hour per 

airplane, at an average labor rate of $80 

per work hour. Based on these figures, 

the estimated cost of this AD for U.S. 

operators is $1,200, or $80 per airplane. 

FAA’s Determination and Requirements 

of This AD 

No additional airplanes affected by 

this AD are on the U.S. Register. We are 

issuing this AD because the unsafe 

condition described previously is likely 

to exist or develop on other products of 

the(se) same type design(s) that could be 

registered in the United States in the 

future. This AD requires inspecting the 

support bracket of the crew oxygen 

cylinder installation to determine the 

manufacturing date marked on the 

support, and performing corrective 

action if necessary. 

Since no additional airplanes that are 

U.S. registered are affected by this AD, 

notice and opportunity for public 

comment before issuing this AD are 

unnecessary. 


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