This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

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Rules and Regulations Federal Register

13187 

Vol. 77, No. 44 

Tuesday, March 6, 2012 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0107; Directorate 

Identifier 2007–NM–087–AD; Amendment 

39–16965; AD 2012–04–09] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for certain 

The Boeing Company Model 747–100, 

747–100B, 747–100B SUD, 747–200B, 

747–200C, 747–200F, 747–300, 747– 

400, 747–400D, 747–400F, 747SR, and 

747SP series airplanes. This AD requires 

inspections for scribe lines in affected 

lap and butt splices, wing-to-body 

fairing locations, and external repair 

and cutout reinforcement areas; and 

related investigative and corrective 

actions if necessary. This AD was 

prompted by reports of scribe lines 

found at lap joints and butt joints, 

around external doublers and antennas, 

and at locations where external decals 

had been cut. We are issuing this AD to 

detect and correct scribe lines, which 

can develop into fatigue cracks in the 

skin and cause sudden decompression 

of the airplane. 

DATES: This AD is effective April 10, 

2012. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in the AD 

as of April 10, 2012. 

ADDRESSES: For service information 

identified in this AD, contact Boeing 

Commercial Airplanes, Attention: Data 

& Services Management, P.O. Box 3707, 

MC 2H–65, Seattle, Washington 98124– 

2207; telephone 206–544–5000, 

extension 1; fax 206–766–5680; email 

me.boecom@boeing.com; Internet 

https://www.myboeingfleet.com. You 

may review copies of the referenced 

service information at the FAA, 

Transport Airplane Directorate, 1601 

Lind Avenue SW., Renton, Washington. 

For information on the availability of 

this material at the FAA, call 425–227– 

1221. 

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 (phone: 800–647–5527) is 

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: Bill 

Ashforth, Aerospace Engineer, Airframe 

Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue SW., Renton, Washington 

98057–3356; phone: 425–917–6432; fax: 

425–917–6590; email: 

bill.ashforth@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a supplemental notice of 

proposed rulemaking (SNPRM) to 

amend 14 CFR part 39 to include an 

airworthiness directive (AD) that would 

apply to the specified products. That 

SNPRM published in the Federal 

Register on August 30, 2010 (75 FR 

52907). The original NPRM (73 FR 5768, 

January 31, 2008) proposed to require 

inspections for scribe lines in affected 

lap and butt splices, wing-to-body 

fairing locations, and external repair 

and cutout reinforcement areas; and 

related investigative and corrective 

actions if necessary. The SNPRM 

proposed to revise the original NPRM by 

adding inspections for certain airplanes 

and revising certain compliance times 

including reducing the compliance time 

for certain repetitive inspections. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. The 

following presents the comments 

received on the proposal (75 FR 52907, 

August 30, 2010) and the FAA’s 

response to each comment. 

Request To Revise Certain Inspection 

Requirements 

Boeing requested that we revise the 

SNPRM (75 FR 52907, August 30, 2010) 

to include an additional exception to 

the service bulletin specifications. The 

SNPRM referred to Boeing Service 

Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010, as the appropriate 

source of service information for the 

post-repair inspections. Revision 4 of 

this service bulletin includes lap joint 

repair instructions in the 

Accomplishment Instructions, and 

refers to post-repair instructions in Parts 

17 and 18. The post-repair inspection 

instructions incorrectly refer to 

inspections per the Boeing 747 

Supplemental Structural Inspection 

Document (SSID) D6–35022. Boeing 

reported that it plans to remove the 

reference to the SSID and update the 

post-repair inspections when Boeing 

Service Bulletin 747–53A2563 is 

revised. Boeing therefore requested that 

we revise the SNPRM to require 

operators to contact the FAA to request 

the appropriate post-repair inspections 

rather than follow the post-repair 

inspections given in Boeing Service 

Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010. 

We partially agree with the request. 

Although we agree with the information 

and rationale provided by the 

commenter, we have determined that 

the inspection procedures described in 

Boeing Service Bulletin 747–53A2563, 

Revision 4, dated May 6, 2010, are 

adequate for the purpose of this AD. It 

is not necessary to further burden the 

operators with a requirement to contact 

the FAA for post-repair inspection 

instructions, when adequate inspections 

already exist. Operators may, however, 

contact the FAA with an alternative 

method to the inspection procedures 

specified in Boeing Service Bulletin 

747–53A2563, Revision 4, dated May 6, 

2010, in accordance with the procedures 

specified in paragraph (m) of this AD. 


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13188 Federal Register / Vol. 77, No. 44 / Tuesday, March 6, 2012 / Rules and Regulations 

Request To Remove Certain Inspection 

Requirement 

Boeing and Delta Airlines requested 

that we revise paragraph (g) of the 

SNPRM (75 FR 52907, August 30, 2010) 

to remove the requirement to inspect for 

scribe lines around the perimeter of the 

wing-to-body fairing. The commenters 

stated that this inspection has been 

removed from Boeing Service Bulletin 

747–53A2563, Revision 4, dated May 6, 

2010. Boeing noted that repetitive 

inspections for cracks at previously 

discovered scribe lines along the wingto-body fairing may still be necessary, as 

specified in Table 17 of paragraph 1.E., 

‘‘Compliance,’’ of Boeing Service 

Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010. 

We partially agree with the request. 

We agree that the initial inspection of 

the wing-to-body fairing for scribe lines 

is not required; this action was removed 

from Boeing Service Bulletin 747– 

53A2563, Revision 3, dated June 11, 

2009; and Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 

2010. But we disagree that it is 

necessary to change the final rule to 

specify this provision; Note 1, which 

was added to the SNPRM (75 FR 52907, 

August 30, 2010) and retained in this 

final rule, accounts for this requested 

change. We have not changed the final 

rule regarding this issue. 

Request To Clarify Reporting 

Requirement 

Delta requested that we revise 

paragraph (j) of the SNPRM (75 FR 

52907, August 30, 2010) (paragraph (k) 

in this final rule) to specify that the 

inspection report is required only for 

the initial inspection for scribe lines. 

The commenter noted that the service 

bulletin has no provision for reporting 

requirements for any repetitive 

inspections done during the limited 

return to service (LRTS) program 

specified in Boeing Service Bulletin 

747–53A2563, Revision 4, dated May 6, 

2010. 

We agree to clarify that a report is not 

required for any inspection 

accomplished per the LRTS program. 

We have added this clarification in 

paragraph (k) in this final rule. 

Request To Extend Certain Compliance 

Times 

Air New Zealand discussed the 

implications of scribe lines found before 

the applicable inspection threshold. 

This commenter asserted that a scribe 

line could be present on the airplane 

from its date of manufacture, and that 

Boeing Service Bulletin 747–53A2563, 

Revision 4, dated May 6, 2010, 

effectively declares there is no safety 

implication resulting from this scribe 

line until the relevant inspection 

threshold. Yet the SNPRM (75 FR 

52907, August 30, 2010) would require 

that a scribe line found before the 

inspection threshold must immediately 

be repaired or further inspected. Air 

New Zealand asserted that, if scribe 

lines are discovered early, this 

requirement would add to the 

maintenance burden without increasing 

safety. 

We infer that the commenter is 

requesting that we revise the SNPRM 

(75 FR 52907, August 30, 2010) to 

extend the time for corrective action on 

known scribe lines to match the 

threshold specified in the service 

information, instead of requiring action 

before further flight. We disagree. We 

have determined that, in this case, due 

to the safety implications and 

consequences of this type of known 

damage, operators must repair or 

inspect scribed structure before further 

flight. We have not changed the final 

rule regarding this issue. 

Request To Remove Certain Airplanes 

From Inspection Requirements 

Cargolux Airlines asserted that certain 

airplanes should not be subject to the 

inspection requirement, and requested 

that we revise the SNPRM (75 FR 52907, 

August 30, 2010) to exclude airplanes 

delivered without fillet seals at lap 

joints, and airplanes with fillet seals 

that were applied but never removed. 

The operator noted that Boeing Service 

Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010, provides some 

exceptions for airplanes that had never 

been stripped or repainted, and for 

airplanes on which any sealant removal 

was always done in accordance with 

Appendix A of this service bulletin. The 

operator also noted, on the other hand, 

that no exception exists if fillet seals 

were never applied, or were applied but 

never removed. Paragraph 1.D. of this 

service bulletin specifies that scribe 

lines are made while fillet seals are 

removed during repainting. The 

commenter concluded that if no fillet 

seal was ever applied at a lap joint 

location, or if an applied fillet seal was 

never removed, no scribe line can exist. 

We disagree with the commenter’s 

request to remove certain airplanes from 

the inspections required by this AD. As 

noted in paragraph 1.E.1 of Boeing 

Service Bulletin 747–53A2563, Revision 

4, dated May 6, 2010, certain 

inspections are still necessary even if no 

fillet seal has ever been removed. We do 

not agree to exempt airplanes on which 

no fillet seal has ever been removed 

from those inspections. The valid 

exceptions to certain inspections are 

explained further in Paragraphs 1.E.1 

through 1.E.4 of Boeing Service Bulletin 

747–53A2563, Revision 4, dated May 6, 

2010. Note 1 of this AD states that the 

exemptions noted in paragraph 1.E. of 

Boeing Service Bulletin 747–53A2563, 

Revision 4, dated May 6, 2010, apply to 

this AD. It is not necessary to change the 

final rule regarding this issue. 

Request To Revise Compliance Time 

British Airways (BA) requested that 

we revise the SNPRM (75 FR 52907, 

August 30, 2010) to allow low-time 

airplanes (with fewer than 17,500 total 

accumulated flight cycles) to be 

inspected in area 1 of the fuselage at the 

later of 1,500 flight cycles after the 

effective date of the AD, and the next 

‘‘D’’ check after the airplane has 

accumulated 15,000 total cycles without 

exceeding 19,000 total flight cycles. BA 

noted that Boeing recommends a 

15,000-flight-cycle threshold for the area 

1 inspections, and that the inspections 

should be done during a ‘‘D’’ check to 

avoid unscheduled downtime. As a 

result, to align with a ‘‘D’’ check, the 

inspections for low-time airplanes may 

have to occur as early as 12,000 total 

flight cycles for long-haul airplanes, and 

even earlier for short-haul airplanes. 

The commenter added that Boeing 

Service Bulletin 747–53A2563, Revision 

4, dated May 6, 2010, also includes 

procedures for inspecting for scribe 

lines around external fuselage repairs, 

and as such, shares commonality with 

the need to assess repairs as detailed in 

Boeing SSID D6–36181, which the FAA 

approved in 2008. This program’s 

threshold is the first ‘‘D’’ check after the 

airplane has accumulated 15,000 total 

flight cycles. The commenter felt it 

would be appropriate to carry out the 

scribe line inspection of area 1 and the 

repair assessment program at the same 

time. BA stated that it understands that 

the term ‘‘D check’’ means different 

things to different operators, but pointed 

out that in the past the FAA has been 

able to clarify this, for example, in 

paragraph 217 of FAA Advisory Circular 

120–93, dated November 20, 2007 

(http://rgl.faa.gov/Regulatory_and

_Guidance_Library/rgAdvisory

Circular.nsf/1ab39b4ed563b089

85256a35006d56af/f73fd2a31b

353a71862573b000521928!Open

Document), which states as follows: 

Airplanes less than 75 percent of DSG 

[design service goal] on December 18, 2009. 

Operators complete a survey at the first 

heavy maintenance check (time limit 

equivalent to a ‘‘D-check’’) after an 

individual airplane reaches 75% of the DSG, 

not to exceed the DSG. 


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Federal Register / Vol. 77, No. 44 / Tuesday, March 6, 2012 / Rules and Regulations 13189 

Note: A heavy maintenance check (D-check 

or equivalent airplane inspection) is an 

airplane maintenance visit where the major 

structural inspections are performed. In some 

cases, this may be a formal D-check or, in the 

case of a Maintenance Steering Group 

(MSG)–2 or –3 based maintenance program, 

the D-check equivalent may be the ‘‘C-check’’ 

multiple that contains the majority of the 

major structural inspections, such as a ‘‘C–4’’ 

which is sometimes called a heavy 

maintenance visit. 

BA stated that its proposed variation 

on the threshold for area 1 would follow 

this convention, but have the additional 

safeguard that the airplane would not 

exceed 19,000 total flight cycles before 

inspection. Younger airplanes therefore 

would have the same or greater level of 

safety than airplanes currently 

inspected at 17,500 total flight cycles 

and allowed a 1,500-flight-cycle grace 

period. BA reported that, of 314 Model 

747 airplanes that have accumulated 

more than 19,000 total flight cycles, 

none had experienced cracking from 

scribe lines—even though exploratory 

inspections to date suggest that scribe 

lines are commonplace. 

We disagree with the request to revise 

the compliance time as suggested. We 

do not specify compliance times in 

terms of letter checks because, as the 

commenter noted, maintenance 

schedules vary among operators. We 

have determined that the compliance 

times as proposed are appropriate to 

address the identified unsafe condition. 

The minimum grace period for 

compliance with this AD is 1,500 flight 

cycles for airplanes with fewer than 

17,500 total flight cycles, which 

corresponds to approximately 3 years 

based on a typical utilization of 500 

flight cycles per year for long-haul 

airplanes. A 3-year grace period should 

be sufficient for operators to plan for the 

scribe line inspections, and will allow 

for timely data collection for use in 

developing final action and determining 

whether this AD should be revised in 

the future. We have not changed the 

final rule regarding this issue. Under the 

provisions of paragraph (m) in this final 

rule, however, we may consider 

requests for adjustments to the 

compliance time if data are submitted to 

substantiate that such an adjustment 

would provide an acceptable level of 

safety. 

Request for Alternative Inspection 

Program 

KLM requested that we revise the 

SNPRM (75 FR 52907, August 30, 2010) 

to exclude from the inspection program 

the CLAD layer of the skin (up to a 

certain depth/percentage, to be 

determined by the type certificate 

holder). KLM asserted that scribe lines 

found in the CLAD layer are not critical 

for continued operation and do not 

require repeat inspections as specified 

in the LRTS program. KLM also 

requested investigation of a single 

fatigue crack evolving from a scribe line 

found in the CLAD layer, not in the base 

material. KLM requested that the 

proposed AD be revised to allow 

blending scribe lines found in CLAD 

layers as a corrective action. KLM 

suggested that scribe lines might have 

no effect on the CLAD layer, and 

suggested that a program be developed 

for inspecting scribe lines in the CLAD 

layer of the skin. 

We agree that additional studies on 

scribe lines within CLAD layers might 

benefit the development of new 

inspection programs and relieve certain 

inspection criteria. But we disagree to 

change this aspect of the SNPRM (75 FR 

52907, August 30, 2010) at this time, 

because no such inspection program 

exists. To delay this action would be 

inappropriate, since we have 

determined that an unsafe condition 

exists and we must proceed to mandate 

the inspections as proposed to ensure 

continued safety. In the future, we 

might consider additional rulemaking to 

include new inspections, if a new 

inspection program is developed, 

approved, and available. In the 

meantime, under the provisions of 

paragraph (m) of this final rule, we will 

consider requests for approval of an 

alternative method of compliance if 

sufficient data are submitted to 

substantiate that the alternative 

inspection program would provide an 

acceptable level of safety. We have not 

changed the final rule regarding this 

issue. 

Explanation of Additional Change 

Made to This AD 

We have revised the heading for and 

wording in paragraph (l) of this AD; this 

change has not changed the intent of 

that paragraph. 

Conclusion 

We reviewed the relevant data, 

considered the comments received, and 

determined that air safety and the 

public interest require adopting the AD 

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 219 

airplanes of U.S. registry. We estimate 

the following costs to comply with this 

AD: 

ESTIMATED COSTS

Action Work 

hours 

Average 

labor rate 

per hour 

Cost per 

airplane 

Number of 

U.S.-registered 

airplanes 

Fleet cost 

Detailed inspections ......... 1,020 to 1,140 ................ $85 $86,700 to $96,900 ........ 219 $18,987,300 to 

$21,221,100. 

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 

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: 


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13190 Federal Register / Vol. 77, No. 44 / Tuesday, March 6, 2012 / Rules and Regulations 

(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), 

(3) Will not affect intrastate aviation 

in Alaska, and 

(4) 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. 

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): 

2012–04–09 The Boeing Company: 

Amendment 39–16965; Docket No. 

FAA–2008–0107; Directorate Identifier 

2007–NM–087–AD. 

(a) Effective Date 

This AD is effective April 10, 2012. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to The Boeing Company 

Model 747–100, 747–100B, 747–100B SUD, 

747–200B, 747–200C, 747–200F, 747–300, 

747–400, 747–400D, 747–400F, 747SP, and 

747SR series airplanes; certificated in any 

category; as identified in Boeing Service 

Bulletin 747–53A2563, Revision 4, dated 

May 6, 2010. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 53: Fuselage. 

(e) Unsafe Condition 

This AD results from reports of scribe lines 

found at lap joints and butt joints, around 

external doublers and antennas, and at 

locations where external decals had been cut. 

We are issuing this AD to detect and correct 

scribe lines, which can develop into fatigue 

cracks in the skin and cause sudden 

decompression of the airplane. 

(f) Compliance 

You are responsible for having the actions 

required by this AD performed within the 

compliance times specified, unless the 

actions have already been done. 

(g) Inspection 

At the applicable times specified in Tables 

1 through 21 and Table 25 in paragraph 1.E., 

‘‘Compliance,’’ of Boeing Service Bulletin 

747–53A2563, Revision 4, dated May 6, 2010, 

except as provided in paragraph (h) of this 

AD, do detailed inspections for scribe lines 

of affected lap and butt splices, wing-to-body 

fairing locations, and external repair and 

cutout reinforcement areas, and do all 

applicable related investigative and 

corrective actions, by accomplishing all 

actions specified in the Accomplishment 

Instructions of Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 2010, 

except as provided by paragraph (i) of this 

AD. 

Note 1 to paragraph (g) of this AD: The 

inspection exemptions noted in paragraph 

1.E., ‘‘Compliance,’’ of Boeing Service 

Bulletin 747–53A2563, Revision 4, dated 

May 6, 2010, apply to this AD, provided that 

the operator meets the requirements stated in 

each applicable exemption. 

(h) Exceptions to Service Bulletin 

Specifications: Compliance Time 

Where Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 2010, 

specifies a compliance time after the date on 

that revision or any previous issue of Boeing 

Service Bulletin 747–53A2563, this AD 

requires compliance within the specified 

compliance time after the effective date of 

this AD. Where Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 2010, 

states that airplane flight-cycle time shall be 

calculated after the ‘‘issue date on this 

service bulletin,’’ this AD requires the 

airplane flight-cycle time to be calculated as 

of the effective date of this AD. 

(i) Exception to Service Bulletin 

Specifications: Repair Method 

Where Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 2010, 

specifies to contact Boeing for appropriate 

action, accomplish applicable actions before 

further flight using a method approved in 

accordance with the procedures specified in 

paragraph (m) of this AD. 

(j) Report 

At the applicable time specified in 

paragraph (j)(1) or (j)(2) of this AD: Submit 

a report of the findings (both positive and 

negative) of the inspections required by 

paragraphs (g) and (k) of this AD. Send the 

report to Boeing Commercial Airplanes, P.O. 

Box 3707, Seattle, Washington 98124–2207. 

The report must contain, at a minimum, the 

inspection results, a description of any 

discrepancies including maximum scribe 

depth, the airplane serial number, and the 

number of flight cycles and flight hours on 

the airplane. 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. A report is not required for any 

inspection accomplished in accordance with 

the Limited Return to Service (LRTS) 

program. 

(1) If the inspection was done on or after 

the effective date of this AD: Submit the 

report within 30 days after the inspection. 

(2) If the inspection was done before the 

effective date of this AD: Submit the report 

within 30 days after the effective date of this 

AD. 

(k) Additional Inspections for Previously 

Inspected Airplanes 

For airplanes that have been inspected 

before the effective date of this AD in 

accordance with the service information 

specified in table 1 of this AD: At the 

applicable times specified in Tables 22 

through 24 and Tables 26 through 29 of 

paragraph 1.E., ‘‘Compliance,’’ of Boeing 

Service Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010, except as provided in 

paragraph (h) of this AD, do detailed 

inspections for scribe lines of affected lap 

splices, butt splices and cargo door lap 

splices; and do detailed and surface high 

frequency eddy current or ultrasonic 

inspections of scribe lines; and do all 

applicable related investigative and 

corrective actions; by accomplishing all the 

applicable actions specified in the 

Accomplishment Instructions of Boeing 

Service Bulletin 747–53A2563, Revision 4, 

dated May 6, 2010, except as provided by 

paragraph (i) of this AD. 

TABLE 1—PREVIOUS SERVICE BULLETIN REVISIONS

Document Revision Date 

Boeing Alert Service Bulletin 747–53A2563 ............................................................. Original .................................................... March 29, 2007. 

Boeing Service Bulletin 747–53A2563 ...................................................................... 2 .............................................................. January 3, 2008. 

Boeing Service Bulletin 747–53A2563 ...................................................................... 3 .............................................................. June 11, 2009. 

Note 2 to paragraph (k) of this AD: Boeing 

Alert Service Bulletin 747–53A2563, 

Revision 1, dated November 8, 2007, was 

published with omitted information. Actions 

accomplished according to Boeing Alert 

Service Bulletin 747–53A2563, Revision 1, 

dated November 8, 2007, are not considered 

acceptable for compliance with this AD. 


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Federal Register / Vol. 77, No. 44 / Tuesday, March 6, 2012 / Rules and Regulations 13191 

(l) Credit for Previous Actions 

This paragraph provides credit for the 

actions required by paragraph (g) of this AD, 

if those actions were performed before the 

effective date of this AD using the service 

information identified in Table 1 of this AD, 

except as required by paragraph (k) of this 

AD. 

(m) Alternative Methods of Compliance 

(AMOCs) 

(1) The Manager, Seattle Aircraft 

Certification Office, FAA, has the authority to 

approve AMOCs for this AD, if requested 

using the procedures found in 14 CFR 39.19. 

In accordance with 14 CFR 39.19, send your 

request to your principal inspector or local 

Flight Standards District Office, as 

appropriate. Information may be mailed to 9- 

ANM-Seattle-ACO-AMOC-Requests@faa.gov. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the local flight standards district office/ 

certificate holding district office. 

(3) An AMOC that provides an acceptable 

level of safety may be used for any repair 

required by this AD, if it is approved by the 

Boeing Commercial Airplanes Organization 

Designation Authority (ODA) that has been 

authorized by the Manager, Seattle ACO, to 

make those findings. For a repair method to 

be approved, the repair must meet the 

certification basis of the airplane, and the 

approval must specifically refer to this AD. 

(n) Related Information 

For more information about this AD, 

contact Bill Ashforth, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue SW., Renton, Washington 98057– 

3356; phone: 425–917–6432; fax: 425–917– 

6590; email: bill.ashforth@faa.gov. 

(o) Material Incorporated by Reference 

You must use Boeing Service Bulletin 747– 

53A2563, Revision 4, dated May 6, 2010, 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, Attention: Data & Services 

Management, P.O. Box 3707, MC 2H–65, 

Seattle, Washington 98124–2207; telephone 

206–544–5000, extension 1; fax 206–766– 

5680; email me.boecom@boeing.com; Internet 

https://www.myboeingfleet.com. 

(3) You may review copies of the service 

information at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue SW., Renton, 

Washington. For information on the 

availability of this material at the FAA, call 

425–227–1221. 

(4) You may also review copies of the 

service information that is incorporated by 

reference at the National Archives and 

Records Administration (NARA). For 

information on the availability of this 

material at an NARA facility, 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 February 

17, 2012. 

Kalene C. Yanamura, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2012–4520 Filed 3–5–12; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–0992; Directorate 

Identifier 2011–NM–126–AD; Amendment 

39–16968; AD 2012–04–12] 

RIN 2120–AA64 

Airworthiness Directives; Bombardier, 

Inc. Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for certain 

Bombardier, Inc. Model CL–600–2B16 

(CL–604 Variant) airplanes. This AD 

was prompted by reports of the airdriven generator (ADG) failing to 

provide power during operational/ 

function checks due to wires in the ADG 

power feeder cables being damaged. The 

damage was due to galvanic corrosion 

and inadequate silver-plating. This AD 

requires replacing ADG power feeder 

cables. We are issuing this AD to 

prevent galvanic corrosion on ADG 

power feeder cables, which could result 

in damage to the cable and consequently 

the cable may not be able to provide 

emergency electrical power to the 

airplane. 

DATES: This AD becomes effective April 

10, 2012. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of April 10, 2012. 

ADDRESSES: You may examine the AD 

docket on the Internet at http:// 

www.regulations.gov or in person at the 

U.S. Department of Transportation, 

Docket Operations, M–30, West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue SE., 

Washington, DC. 

FOR FURTHER INFORMATION CONTACT: 

Assata Dessaline, Aerospace Engineer, 

Avionics and Flight Test Branch, ANE– 

172, FAA, New York Aircraft 

Certification Office, 1600 Stewart 

Avenue, Suite 410, Westbury, New York 

11590; telephone (516) 228–7301; fax 

(516) 794–5531. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to include an AD that would 

apply to the specified products. That 

NPRM was published in the Federal 

Register on September 23, 2011 (76 FR 

59067). That NPRM proposed to correct 

an unsafe condition for the specified 

products. The MCAI states: 

Three (3) events have occurred where the 

Air-Driven Generator (ADG) failed to provide 

power on CL–600–2B19 (CRJ) aeroplanes 

during their regularly scheduled operational/ 

functional checks. An investigation revealed 

that in all cases, the silver-plated copper 

wires within the ADG power feeder cables 

were damaged due to galvanic corrosion. It 

was subsequently determined that the silverplating is inadequate for this application. 

In the event of damage to the power feeder 

cable wires, the ADG may not be able to 

provide emergency electrical power to the 

aeroplane. 

Although there have been no reported 

failures to date on any CL–600–2B16 (604 

Variant) aeroplanes, a sampling program 

carried out on these aeroplanes showed signs 

of microscopic galvanic corrosion on the 

ADG power feeder cable wires. 

This [Transport Canada] directive is issued 

to correct this potentially unsafe condition by 

mandating the replacement of all ADG power 

feeder cables * * * with an ADG power 

feeder cable that contains tin-plated copper 

wires. 

You may obtain further information by 

examining the MCAI in the AD docket. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. We 

considered the comment received. 

Request To Revise Applicability 

Bombardier Aerospace (Bombardier) 

commented that the aircraft 

applicability needs to be revised to 

remove two of the three model 

designations (Model CL–601–3A and 

–3R) specified in the NPRM (76 FR 

59067, September 23, 2011), because 

only airplanes of the Model CL–604 

Variant are affected by the proposed 

actions of the NPRM. 

We agree to revise the applicability of 

this AD as requested. The airplane serial 

numbers specified in Transport Canada 

Civil Aviation (TCCA) Airworthiness 

Directive CF–2011–08, dated April 28, 

2011 (cited in the NPRM (76 FR 59067, 

September 23, 2011) as the Canadian 

mandatory continuing airworthiness 

information (MCAI)), and Bombardier 

Service Bulletin 604–24–024, dated 

January 31, 2011 (cited as the 

appropriate service information for 

accomplishing the actions proposed by 

the NPRM) are all of the Model CL–604 


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