Federal Register / Vol. 80, No. 229 / Monday, November 30, 2015 / Proposed Rules 74723 

a proposed AD (80 FR 32315, June 8, 

2015). The proposed AD had applied to 

Rolls-Royce Deutschland Ltd & Co KG 

(RRD) Tay 650–15 and Tay 651–54 

turbofan engines. The NPRM proposed 

to reduce the cyclic life limits for 

certain HPT disks. The proposed action 

was prompted by an analysis that 

showed the need to reduce the cyclic 

life limits for certain HPT disks. The 

proposed actions intended to prevent 

failure of the HPT disk, which could 

result in uncontained disk release, 

damage to the engine, and damage to the 

airplane. 

Since we issued the NPRM (80 FR 

32315, June 8, 2015), additional 

information became available after the 

public comment period closed on 

August 7, 2015. 

Upon further consideration, we 

hereby withdraw the proposed rule 

because we will propose to supersede 

AD 2006–18–14 (71 FR 52988, 

September 8, 2006). 

Withdrawal of the NPRM (80 FR 

32315, June 8, 2015) constitutes only 

such action, and does not preclude the 

agency from issuing another notice in 

the future, nor does it commit the 

agency to any course of action in the 

future. 

Since this action only withdraws a 

notice of proposed rulemaking, it is 

neither a proposed nor a final rule. 

Therefore, Executive Order 12866, the 

Regulatory Flexibility Act, or DOT 

Regulatory Policies and Procedures (44 

FR 11034, February 26, 1979) do not 

cover this withdrawal. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

The Withdrawal 

Accordingly, the notice of proposed 

rulemaking, Docket No. FAA–2015– 

1014; Directorate Identifier 2015–NE– 

14–AD, published in the Federal 

Register on June 8, 2015 (80 FR 32315), 

is withdrawn. 

Issued in Burlington, Massachusetts, on 

November 20, 2015. 

Colleen M. D’Alessandro, 

Directorate Manager, Engine & Propeller 

Directorate, Aircraft Certification Service. 

[FR Doc. 2015–30010 Filed 11–27–15; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2015–6539; Directorate 

Identifier 2015–NM–036–AD] 

RIN 2120–AA64 

Airworthiness Directives; Airbus 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for all 

Airbus Model A318–111 and –112 

airplanes; Model A319–111, –112, –113, 

–114, and –115 airplanes; Model A320– 

211, –212, and –214 airplanes; and 

Model A321–111, –112, –211, –212, and 

–213 airplanes. This proposed AD was 

prompted by an evaluation by the 

design approval holder (DAH) 

indicating that the forward engine 

mounts are subject to widespread 

fatigue damage (WFD). This proposed 

AD would require repetitive detailed 

inspections of the right and left forward 

engine mounts, and corrective action if 

necessary. These inspections are 

required by AD 2015–05–02. This 

proposed AD would reduce the 

compliance times for those inspections. 

We are proposing this AD to detect and 

correct fatigue cracking in the forward 

engine mounts, which could result in 

reduced structural integrity of the 

airplane and could lead to in-flight loss 

of an engine, possibly resulting in 

reduced controllability of the airplane. 

DATES: We must receive comments on 

this proposed AD by January 14, 2016. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, 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, between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

For service information identified in 

this proposed AD, contact Airbus, 

Airworthiness Office—EIAS, 1 Rond 

Point Maurice Bellonte, 31707 Blagnac 

Cedex, France; telephone +33 5 61 93 36 

96; fax +33 5 61 93 44 51; email 

account.airworth–eas@airbus.com; 

Internet http://www.airbus.com. You 

may view this referenced service 

information at the FAA, Transport 

Airplane Directorate, 1601 Lind Avenue 

SW., Renton, WA. 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 by searching for 

and locating Docket No. FAA–2015– 

6539; 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 Operations 

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: 

Sanjay Ralhan, Aerospace Engineer, 

International Branch, ANM–116, 

Transport Airplane Directorate, FAA, 

1601 Lind Avenue SW., Renton, WA 

98057–3356; telephone 425–227–1405; 

fax 425–227–1149. 

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–2015–6539; Directorate Identifier 

2015–NM–036–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 based on 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 

Structural fatigue damage is 

progressive. It begins as minute cracks, 

and those cracks grow under the action 

of repeated stresses. This can happen 

because of normal operational 

conditions and design attributes, or 


jstallworth on DSK7TPTVN1PROD with PROPOSALS
74724 Federal Register / Vol. 80, No. 229 / Monday, November 30, 2015 / Proposed Rules 

because of isolated situations or 

incidents such as material defects, poor 

fabrication quality, or corrosion pits, 

dings, or scratches. Fatigue damage can 

occur locally, in small areas or 

structural design details, or globally. 

Global fatigue damage is general 

degradation of large areas of structure 

with similar structural details and stress 

levels. Multiple-site damage is global 

damage that occurs in a large structural 

element such as a single rivet line of a 

lap splice joining two large skin panels. 

Global damage can also occur in 

multiple elements such as adjacent 

frames or stringers. Multiple–sitedamage and multiple-element-damage 

cracks are typically too small initially to 

be reliably detected with normal 

inspection methods. Without 

intervention, these cracks will grow, 

and eventually compromise the 

structural integrity of the airplane, in a 

condition known as widespread fatigue 

damage (WFD). As an airplane ages, 

WFD will likely occur, and will 

certainly occur if the airplane is 

operated long enough without any 

intervention. 

The FAA’s WFD final rule (75 FR 

69746, November 15, 2010) became 

effective on January 14, 2011. The WFD 

rule requires certain actions to prevent 

structural failure due to WFD 

throughout the operational life of 

certain existing transport category 

airplanes and all of these airplanes that 

will be certificated in the future. For 

existing and future airplanes subject to 

the WFD rule, the rule requires that 

DAHs establish a limit of validity (LOV) 

of the engineering data that support the 

structural maintenance program. 

Operators affected by the WFD rule may 

not fly an airplane beyond its LOV, 

unless an extended LOV is approved. 

The WFD rule (75 FR 69746, 

November 15, 2010) does not require 

identifying and developing maintenance 

actions if the DAHs can show that such 

actions are not necessary to prevent 

WFD before the airplane reaches the 

LOV. Many LOVs, however, do depend 

on accomplishment of future 

maintenance actions. As stated in the 

WFD rule, any maintenance actions 

necessary to reach the LOV will be 

mandated by airworthiness directives 

through separate rulemaking actions. 

In the context of WFD, this action is 

necessary to enable DAHs to propose 

LOVs that allow operators the longest 

operational lives for their airplanes, and 

still ensure that WFD will not occur. 

This approach allows for an 

implementation strategy that provides 

flexibility to DAHs in determining the 

timing of service information 

development (with FAA approval), 

while providing operators with certainty 

regarding the LOV applicable to their 

airplanes. 

Failure of a forward engine mount 

could lead to in-flight loss of an engine, 

possibly resulting in reduced 

controllability of the airplane. 

The European Aviation Safety Agency 

(EASA), which is the Technical Agent 

for the Member States of the European 

Union, has issued EASA Airworthiness 

Directive 2015–0038, dated March 4, 

2015 (referred to after this as the 

Mandatory Continuing Airworthiness 

Information, or ‘‘the MCAI’’), to correct 

an unsafe condition for all Airbus 

Model A318–111 and –112 airplanes; 

Model A319–111, –112, –113, –114, and 

–115 airplanes; Model A320–211, –212, 

and –214 airplanes; and Model A321– 

111, –112, –211, –212, and –213 

airplanes. The MCAI states: 

During a A320 Extended Service Goal 

(ESG) residual fatigue test, in which new 

loads were used, taking into account the 

results of the 2006 fleet survey, the CFM56– 

5A/5B forward engine mount experienced a 

failure before reaching the threshold/interval 

for the detailed inspection of that forward 

engine mount, as identified in Airbus A318/ 

A319/A320/A321 Airworthiness Limitations 

Section (ALS) Part 2 (hereafter referred to in 

this [EASA] AD as ‘the ALS’) task 712111– 

01. In case of total loss of the primary load 

path, the current maintenance requirements 

do not ensure the design integrity of the 

remaining structure. 

This condition, if not corrected, could lead 

to in-flight loss of an engine, possibly 

resulting in reduced control of the aeroplane 

and injury to persons on the ground. 

For the reasons described above, this 

[EASA] AD requires implementation of a 

reduced threshold and interval for the 

detailed inspections (DET) of the forward 

engine mount on both right hand (RH) and 

left hand (LH) sides, as specified in the ALS, 

task 712111–01. 

Once further investigations and test are 

completed, the threshold and interval of the 

ALS task 712111–01 will likely be modified 

accordingly. 

Required actions include repair of 

discrepancies (cracks) found during the 

inspection. You may examine the MCAI 

in the AD docket on the Internet at 

http://www.regulations.gov by searching 

for and locating Docket No. FAA–2015– 

6539. 

Related AD 

AD 2015–05–02, Amendment 39– 

18112 (80 FR 15152, March 23, 2015), 

which is applicable to all Airbus Model 

A318, A319, A320, and A321 series 

airplanes, requires revising the 

maintenance or inspection program, as 

applicable, to incorporate certain 

Airworthiness Limitation Items. 

Paragraph (n)(2) of AD 2015–05–02 

requires incorporating Part 2-Damage– 

Tolerant Airworthiness Limitation Items 

(DT ALI), of the Airbus A318/A319/

A320/A321 ALS, Revision 02, dated 

May 28, 2013. AD 2015–05–02 

corresponds to EASA AD 2013–0147, 

dated July 16, 2013. We considered the 

fleet size that would be affected by 

superseding AD 2015–05–02, and the 

consequent workload associated with 

revising maintenance record entries, 

and determined that this proposed AD 

should not supersede AD 2015–05–02. 

Although this proposed AD would not 

supersede AD 2015–05–02, paragraph 

(g) of this proposed AD would terminate 

the initial and repetitive inspections for 

the corresponding inspections in 

paragraph (n)(2) of AD 2015–05–02, 

Amendment 39–18112 (80 FR 15152, 

March 23, 2015), for Airbus 

Airworthiness Limitation Tasks 

712111–01–1, 712111–01–2, 712111– 

01–3, and 71211–01–4, ‘‘Detailed 

Inspection of Forward Engine Mount 

Installation.’’ 

FAA’s Determination and Requirements 

of This Proposed AD 

This product has been approved by 

the aviation authority of another 

country, and is approved for operation 

in the United States. Pursuant to our 

bilateral agreement with the State of 

Design Authority, we have been notified 

of the unsafe condition described in the 

MCAI and service information 

referenced above. We are proposing this 

AD because we evaluated all pertinent 

information and determined an unsafe 

condition exists and is likely to exist or 

develop on other products of these same 

type designs. 

Interim Action 

We consider this proposed AD 

interim action. Once further 

investigations and tests are completed, 

the initial compliance time and 

repetitive intervals for Airbus 

Airworthiness Limitation Tasks 

712111–01–1, 712111–01–2, 712111– 

01–3, and 712111–01–4, ‘‘Detailed 

Inspection of Forward Engine Mount 

Installation,’’ could be revised and we 

might consider further rulemaking at 

that time. 

Costs of Compliance 

We estimate that this proposed AD 

affects 940 airplanes of U.S. registry. 

We also estimate that it would take 

about 1 work-hour per product to 

comply with the basic requirements of 

this proposed AD. The average labor 

rate is $85 per work-hour. Based on 

these figures, we estimate the cost of 

this proposed AD on U.S. operators to 

be $79,900, or $85 per product. 


jstallworth on DSK7TPTVN1PROD with PROPOSALS
Federal Register / Vol. 80, No. 229 / Monday, November 30, 2015 / Proposed Rules 74725 

We have received no definitive data 

that would enable us to provide cost 

estimates for the on-condition parts cost 

specified in 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 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); 

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. 

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 airworthiness 

directive (AD): 

Airbus: Docket No. FAA–2015–6539; 

Directorate Identifier 2015–NM–036–AD. 

(a) Comments Due Date 

We must receive comments by January 14, 

2016. 

(b) Affected AD 

This AD affects AD 2015–05–02, 

Amendment 39–18112 (80 FR 15152, March 

23, 2015). 

(c) Applicability 

This AD applies to the Airbus airplanes, 

certificated in any category, identified in 

paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) of 

this AD. 

(1) Model A318–111 and –112 airplanes. 

(2) Model A319–111, –112, –113, –114, and 

–115 airplanes. 

(3) Model A320–211, –212, and –214 

airplanes. 

(4) Model A321–111, –112, –211, –212, and 

–213 airplanes. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 05, Periodic Inspections. 

(e) Reason 

This AD was prompted by an evaluation by 

the design approval holder indicating that 

the forward engine mounts are subject to 

widespread fatigue damage. We are issuing 

this AD to detect and correct fatigue cracking 

in the forward engine mounts, which could 

result in reduced structural integrity of the 

airplane and could lead to in-flight loss of an 

engine, possibly resulting in reduced 

controllability of the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Repetitive Inspections 

At the latest of the times specified in 

paragraphs (g)(1), (g)(2), and (g)(3) of this AD: 

Do a detailed inspection of the left and right 

forward engine mounts for discrepancies 

(cracking), using a method approved by the 

Manager, International Branch, ANM–116, 

Transport Airplane Directorate, FAA. Repeat 

the inspection thereafter at intervals not to 

exceed 800 flight cycles. 

Note 1 to paragraphs (g) and (h) of this AD: 

Guidance for the inspection and engine 

mount replacement can be found in Task 

712111–210–040 of the Airbus A318/A319/

A320/A321 Maintenance Manual. 

(1) Within 800 flight cycles since the first 

flight of the airplane. 

(2) Within 800 flight cycles since the most 

recent detailed inspection specified in Airbus 

Airworthiness Limitation Tasks 712111–01– 

1, 712111–01–2, 712111–01–3, or 712111– 

01–4, ‘‘Detailed Inspection of Forward 

Engine Mount Installation,’’ as applicable. 

(3) Within 800 flight cycles after the 

effective date of this AD. 

(h) Corrective Action 

If any discrepancy (cracking) is found 

during any inspection required by paragraph 

(g) of this AD: Before further flight, replace 

the affected forward engine mount with a 

serviceable part, using a method approved by 

the Manager, International Branch, ANM– 

116, Transport Airplane Directorate, FAA; or 

the European Aviation Safety Agency 

(EASA); or Airbus’s EASA Design 

Organization Approval (DOA). 

(i) No Terminating Action 

Replacement of a forward engine mount 

does not constitute terminating action for the 

repetitive inspections required by paragraph 

(g) of this AD. 

(j) Termination of Certain Tasks Required by 

AD 2015–05–02, Amendment 39–18112 (80 

FR 15152, March 23, 2015) 

Accomplishment of the inspections 

required by paragraph (g) of this AD 

terminates the initial and repetitive 

inspections specified in paragraph (n)(2) of 

AD 2015–05–02, Amendment 39–18112 (80 

FR 15152, March 23, 2015), for Airbus 

Airworthiness Limitation Tasks 712111–01– 

1, 712111–01–2, 712111–01–3, and 712111– 

01–4, ‘‘Detailed Inspection of Forward 

Engine Mount Installation.’’ 

(k) Other FAA AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, International 

Branch, ANM–116, Transport Airplane 

Directorate, 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. If sending information directly 

to the International Branch, send it to ATTN: 

Sanjay Ralhan, Aerospace Engineer, 

International Branch, ANM–116, Transport 

Airplane Directorate, FAA, 1601 Lind 

Avenue SW., Renton, WA 98057–3356; 

telephone 425–227–1405; fax 425–227–1149. 

Information may be emailed to: 9-ANM-116- 

AMOC-REQUESTS@faa.gov. 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. The AMOC approval letter 

must specifically reference this AD. 

(2) Contacting the Manufacturer: For any 

requirement in this AD to obtain corrective 

actions from a manufacturer, the action must 

be accomplished using a method approved 

by the Manager, International Branch, ANM– 

116, Transport Airplane Directorate, FAA; or 

the EASA; or Airbus’s EASA DOA. If 

approved by the DOA, the approval must 

include the DOA-authorized signature. 


jstallworth on DSK7TPTVN1PROD with PROPOSALS
74726 Federal Register / Vol. 80, No. 229 / Monday, November 30, 2015 / Proposed Rules 

(l) Special Flight Permits 

Special flight permits, as described in 

Section 21.197 and Section 21.199 of the 

Federal Aviation Regulations (14 CFR 21.197 

and 21.199), are not allowed. 

(m) Related Information 

(1) Refer to Mandatory Continuing 

Airworthiness Information (MCAI) EASA 

Airworthiness Directive 2015–0038, dated 

March 4, 2015, for related information. This 

MCAI may be found in the AD docket on the 

Internet at http://www.regulations.gov by 

searching for and locating Docket No. FAA– 

2015–6539. 

(2) For service information identified in 

this AD contact Airbus, Airworthiness 

Office—EIAS, 1 Rond Point Maurice 

Bellonte, 31707 Blagnac Cedex, France; 

telephone +33 5 61 93 36 96; fax +33 5 61 

93 44 51; email account.airworth-eas@

airbus.com; Internet http://www.airbus.com. 

You may view this service information at the 

FAA, Transport Airplane Directorate, 1601 

Lind Avenue SW., Renton, WA. For 

information on the availability of this 

material at the FAA, call 425–227–1221. 

Issued in Renton, Washington, on 

November 20, 2015. 

Jeffrey E. Duven, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2015–30216 Filed 11–27–15; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2015–6541; Directorate 

Identifier 2015–NM–135–AD] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for all The 

Boeing Company Model 737–600, –700, 

–700C, –800, –900, and –900ER series 

airplanes. This proposed AD was 

prompted by reports of a manufacturing 

oversight, in which a supplier omitted 

the required protective finish on certain 

bushings installed in the rear spar upper 

chord on horizontal stabilizers, which 

could lead to galvanic corrosion and 

consequent cracking of the rear spar 

upper chord. This proposed AD would 

require an inspection or records check 

to determine if affected horizontal 

stabilizers are installed, related 

investigative actions, and for affected 

horizontal stabilizers, repetitive 

inspections for any crack of the 

horizontal stabilizer rear spar upper 

chord, and corrective action if 

necessary. We are proposing this AD to 

detect and correct cracking of the rear 

spar upper chord, which can result in 

the failure of the upper chord and 

consequent departure of the horizontal 

stabilizer from the airplane, which can 

lead to loss of continued safe flight and 

landing. 

DATES: We must receive comments on 

this proposed AD by January 14, 2016. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, 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: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

For service information identified in 

this proposed AD, contact Boeing 

Commercial Airplanes, Attention: Data 

& Services Management, P.O. Box 3707, 

MC 2H–65, Seattle, WA 98124–2207; 

telephone: 206–544–5000, extension 1; 

fax: 206–766–5680; Internet: https://

www.myboeingfleet.com. You may view 

this referenced service information at 

the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue SW., 

Renton, WA. For information on the 

availability of this material at the FAA, 

call 425–227–1221. It is also available 

on the Internet at http://

www.regulations.gov by searching for 

and locating Docket No. FAA–2015– 

6541. 

Examining the AD Docket 

You may examine the AD docket on 

the Internet at http://

www.regulations.gov by searching for 

and locating Docket No. FAA–2015– 

6541; 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 

(phone: 800–647–5527) is in the 

ADDRESSES section. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Jason Deutschman, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office 

(ACO), 1601 Lind Avenue SW., Renton, 

WA 98057–3356; phone: 425–917–6595; 

fax: 425–917–6590; email: 

jason.deutschman@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposal. Send your comments to 

an address listed under the ADDRESSES

section. Include ‘‘Docket No. FAA– 

2015–6541; Directorate Identifier 2015– 

NM–135–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 

We received reports of a 

manufacturing oversight, in which the 

required protective finish (zinc-nickel 

alloy plate or cadmium plate) was 

omitted on the 182A1508–4/–5/–6 

bushings (in line with the terminal 

fitting holes) installed in the rear spar 

upper chord on horizontal stabilizers 

with certain serial numbers. This issue 

was discovered after production of the 

affected stabilizers. 

The 182A1508–4/–5/–6 bushings are 

made from aluminum-nickel-bronze. 

Installing these bushings, without the 

required protective finish, into the 

2024–T3511 aluminum horizontal 

stabilizer rear spar upper chord can lead 

to galvanic corrosion between the 

dissimilar metals. Bushings with 

galvanic corrosion, if not corrected, can 

lead to cracking of the rear spar upper 

chord, which can result in the failure of 

the upper chord and consequent 

departure of the horizontal stabilizer 

from the airplane, which can lead to 

loss of continued safe flight and 

landing. 

Related Service Information Under 1 

CFR Part 51 

We reviewed Boeing Alert Service 

Bulletin 737–55A1097, dated July 1, 

2015. The service information describes 

procedures for an inspection or records 

review to determine if affected 

horizontal stabilizers are installed, 


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