Federal Register / Vol. 75, No. 96 / Wednesday, May 19, 2010 / Proposed Rules 27969 

(PMI) or principal avionics inspector (PAI), 

as appropriate, or lacking a principal 

inspector, your local Flight Standards District 

Office. The AMOC approval letter must 

specifically reference this AD. 

Issued in Renton, Washington, on May 5, 

2010. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2010–11901 Filed 5–18–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2010–0481; Directorate 

Identifier 2009–NM–192–AD] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 737–100 and –200 

Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

Model 737–100 and –200 series 

airplanes. This proposed AD would 

require repetitive inspections for 

cracking and damaged fasteners of 

certain fuselage frames and stub beams, 

and corrective actions if necessary. For 

certain airplanes, this proposed AD 

would also require repetitive 

inspections for cracking of the inboard 

chord fastener hole of the frame at body 

station 639, stringer S–16, and 

corrective actions if necessary. For 

certain airplanes, this proposed AD 

would also require an inspection to 

determine the edge margin of the lower 

chord. For airplanes with a certain short 

edge margin, this proposed AD requires 

repetitive inspections for cracking, and 

corrective actions if necessary; replacing 

the lower chord terminates the 

repetitive inspections. This proposed 

AD requires an eventual preventive 

modification. For certain airplanes, 

doing the modification or a repair 

would terminate the repetitive 

inspections for the repaired or modified 

frame only. For airplanes on which the 

modification or repair is done at certain 

body stations, this proposed AD would 

require repetitive inspections for 

cracking of certain frame webs and 

inner and outer chords, and corrective 

actions if necessary. For certain other 

airplanes, this proposed AD requires a 

modification which includes reinforcing 

the body frame inner chords, replacing 

the stub beam upper chords and attach 

angles, and reinforcing the stub beam 

web. This proposed AD results from 

reports of fatigue cracks at certain frame 

sections, in addition to stub beam 

cracking, caused by high flight cycle 

stresses from both pressurization and 

maneuver load. We are proposing this 

AD to detect and correct fatigue 

cracking of certain fuselage frames and 

stub beams, and possible severed 

frames, which could result in reduced 

structural integrity of the frames. This 

reduced structural integrity can increase 

loading in the fuselage skin, which will 

accelerate skin crack growth and result 

in rapid decompression of the fuselage. 

DATES: We must receive comments on 

this proposed AD by July 6, 2010. 

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 proposed 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; e-mail 

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 proposed AD, the 

regulatory evaluation, any comments 

received, and other information. The 

street address for the Docket Office 

(telephone 800–647–5527) is in the 

ADDRESSES section. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Wayne Lockett, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6447; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposed AD. Send your comments 

to an address listed under the 

ADDRESSES section. Include ‘‘Docket No. 

FAA–2010–0481; Directorate Identifier 

2009–NM–192–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 have received reports of fatigue 

cracks found at certain frame sections, 

in addition to stub beam cracking, 

caused by high flight cycle stresses from 

both pressurization and maneuver load. 

Numerous cracks were found in the 

shear ties, webs, and inboard and 

outboard chords of the overwing body 

frames and stub beams between body 

stations 559 and 639. Cracks were also 

found in the webs, attach angles, and 

the upper and lower chords of the stub 

beams. There were reports of sheared 

fasteners in the overwing body frames 

and stub beams in the same location. 

Fatigue cracking of certain fuselage 

frames and stub beams, if not detected 

and corrected, and possible severed 

frames, could result in reduced 

structural integrity of the frames. This 

reduced structural integrity can increase 

loading in the fuselage skin, which will 

accelerate skin crack growth and result 

in rapid decompression of the fuselage. 

Relevant Service Information 

We have reviewed Boeing Service 

Bulletin 737–53–1061, Revision 4, 

including Addendum, dated July 16, 

1992. For airplanes on which a repair 

(Part III) or preventive modification 

(Part II) has not been done, the service 

bulletin describes procedures for 


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27970 Federal Register / Vol. 75, No. 96 / Wednesday, May 19, 2010 / Proposed Rules 

repetitive detailed inspections for cracks 

and damaged fasteners in the 

circumferential frame and the stub beam 

at body stations 559, 578, 597, 616, and 

639, and corrective actions if necessary. 

For Group 1–3 airplanes, the service 

bulletin describes procedures for 

repetitive eddy current inspections for 

cracking of the inboard chord fastener 

hole of the frame at body station 639, 

stringer S–16, and corrective actions if 

necessary. For airplanes on which 

certain stub beam lower chords were 

installed, the service bulletin describes 

procedures for an inspection to 

determine if a short edge margin exists 

in the lower chord and, for airplanes 

with a certain short edge margin, 

repetitive inspections for cracking and 

corrective actions if necessary. For 

airplanes on which either 

circumferential frame at body station 

597 was changed as given in Boeing 

Service Bulletin 737–53–1061, Revision 

1, dated December 16, 1983; Revision 2, 

dated April 18, 1986; or Revision 3, 

dated June 15, 1989; the service bulletin 

describes procedures for repetitive 

detailed inspections for cracking of the 

frame. 

This service bulletin also describes a 

preventive modification, which would 

eliminate the need for the repetitive 

inspections. For airplanes on which the 

modification or repair is done at body 

stations 616 and 639, the service 

bulletin describes procedures for 

repetitive detailed inspections for 

cracking of the body station 616 and 639 

frame webs and inner and outer chords, 

near stringer S–16, and corrective 

actions if necessary. 

The corrective actions include doing 

a repair for any cracking and damaged 

fasteners that are within the limits 

specified, replacing a cracked 

component by installation of a 

preventive modification if the cracks are 

outside the limits, and contacting 

Boeing for instructions if cracks or 

damaged fasteners cannot be repaired in 

accordance with the specified 

procedures or if the upper chord was 

replaced at a certain location. 

For Group 1–3 airplanes, the service 

bulletin describes procedures for a 

modification, which includes 

reinforcing the body frame inner chords, 

replacing the stub beam upper chords 

and attach angles, and reinforcing the 

stub beam web at body stations 597, 

616, and 639. 

Related Rulemaking 

We are in the process of issuing an 

AD that refers to Boeing Alert Service 

Bulletin 737–53A1254, Revision 1, 

dated July 9, 2009, and is related to this 

proposed AD. That service information 

applies to Model 737–200, –300, –400, 

and –500 series airplanes. During 

review of that service information it was 

determined that the same unsafe 

condition exists on earlier Boeing Model 

737–100 and –200 series airplanes 

identified in Boeing Service Bulletin 

737–53–1061, Revision 4, dated July 16, 

1992, referred to in this proposed AD as 

the appropriate source of service 

information for accomplishing the 

actions. 

FAA’s Determination and Requirements 

of This Proposed AD 

We are proposing this AD because we 

evaluated all relevant information and 

determined the unsafe condition 

described previously is likely to exist or 

develop in other products of the same 

type design. This proposed AD would 

require accomplishing the actions 

specified in the service information 

described previously, except as 

discussed under ‘‘Differences Between 

the Proposed AD and the Service 

Information.’’ 

Differences Between the Proposed AD 

and the Service Information 

Although the Accomplishment 

Instructions of Boeing Service Bulletin 

737–53–1061, Revision 4, dated July 16, 

1992, include a modification for Group 

4 airplanes (Model 737–200C airplanes), 

the applicability of this proposed AD 

does not include those airplanes. This 

proposed AD is applicable to passenger 

airplanes only. 

The service bulletin also specifies to 

contact the manufacturer for 

instructions on repairing cracks, but this 

proposed AD would require repairing 

cracks in one of the following ways: 

• Using a method that we approve; or 

• Using data that meet the 

certification basis of the airplane, and 

that have been approved by the Boeing 

Commercial Airplanes Organization 

Delegation Authorization (ODA) that we 

have authorized to make those findings. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 45 airplanes of U.S. 

registry. 

We estimate that it would take about 

4 work-hours per product to comply 

with the proposed inspections. The 

average labor rate is $85 per work-hour. 

Based on these figures, we estimate the 

cost of this proposed inspection to the 

U.S. operators to be $15,300, or $340 per 

product, per inspection cycle. 

We estimate that it would take about 

288 work-hours per product to comply 

with the proposed modification (for 

Group 1–3 airplanes). The average labor 

rate is $85 per work-hour. Required 

parts would cost about $58,742 per 

product. Based on these figures, we 

estimate the cost of this proposed 

modification to the U.S. operators to be 

$83,222 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 

products identified in this rulemaking 

action. 

Regulatory Findings 

We determined that this proposed AD 

would not have federalism implications 

under Executive Order 13132. This 

proposed AD would not have a 

substantial direct effect on the States, on 

the relationship between the national 

Government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify this proposed regulation: 

1. Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

2. Is not a ‘‘significant rule’’ under the 

DOT Regulatory Policies and Procedures 

(44 FR 11034, February 26, 1979), and 

3. Will not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

You can find our regulatory 

evaluation and the estimated costs of 

compliance in the AD Docket. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, 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: 


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Federal Register / Vol. 75, No. 96 / Wednesday, May 19, 2010 / Proposed Rules 27971 

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: 

The Boeing Company: Docket No. FAA– 

2010–0481; Directorate Identifier 2009– 

NM–192–AD. 

Comments Due Date 

(a) We must receive comments by July 6, 

2010. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to The Boeing 

Company Model 737–100 and –200 series 

airplanes, certificated in any category; line 

numbers 1 through 848 inclusive. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 53: Fuselage. 

Unsafe Condition 

(e) This AD results from reports of fatigue 

cracks at certain frame sections, in addition 

to stub beam cracking, caused by high flight 

cycle stresses from both pressurization and 

maneuver load. The Federal Aviation 

Administration is issuing this AD to detect 

and correct fatigue cracking of certain 

fuselage frames and stub beams, and possible 

severed frames, which could result in 

reduced structural integrity of the frames. 

This reduced structural integrity can increase 

loading in the fuselage skin, which will 

accelerate skin crack growth and result in 

rapid decompression of the fuselage. 

Compliance 

(f) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Inspections 

(g) For airplanes on which a repair (Part III 

of the Accomplishment Instructions of 

Boeing Service Bulletin 737–53–1061) or 

preventive modification (Part II of the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061) has not been 

done in accordance with Boeing Service 

Bulletin 737–53–1061 as of the effective date 

of this AD: Before the accumulation of 15,000 

total flight cycles or within 3,000 flight 

cycles after the effective date of this AD, 

whichever occurs later, do the inspections 

required by paragraphs (g)(1) and (g)(2) of 

this AD, in accordance with the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, Revision 4, 

dated July 16, 1992. Repeat the inspection at 

the time specified, until the terminating 

action required by paragraph (l) of this AD 

is done. 

(1) Do a detailed inspection (Part I of the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061) for cracks and 

damaged fasteners of the fuselage frames and 

stub beams. If no crack or damaged fastener 

is found, repeat the inspection thereafter at 

intervals not to exceed 4,500 flight cycles. 

(2) Do an eddy current inspection (Part IV 

of the Accomplishment Instructions of 

Boeing Service Bulletin 737–53–1061) for 

cracking of the inboard chord fastener hole 

of the frame at body station 639, stringer S– 

16. If no crack is found, repeat the inspection 

thereafter at intervals not to exceed 15,000 

flight cycles. 

Note 1: Access and restoration instructions, 

as detailed in the Accomplishment 

Instructions of Boeing Service Bulletin 737– 

53–1061, Revision 4, dated July 16, 1992, are 

not required by this AD. Operators may do 

those actions in accordance with their 

maintenance practices. 

(h) For airplanes on which the body station 

597 frame was changed as of the effective 

date of this AD, in accordance with the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, dated May 28, 

1982; Revision 1, dated December 16, 1983; 

Revision 2, dated April 18, 1986; or Revision 

3, dated June 15, 1989: Within 3,000 flight 

cycles after the effective date of this AD, do 

a detailed inspection for cracking of the 

frame, in accordance with the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, Revision 4, 

dated July 16, 1992. Repeat the detailed 

inspection thereafter at intervals not to 

exceed 4,500 flight cycles. Installation of new 

radius fillers in accordance with the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, Revision 4, 

dated July 16, 1992, terminates the 

inspections required by this paragraph. 

(i) For airplanes on which a stub beam 

lower chord with 1⁄4-inch diameter fasteners 

at body station 597 is installed as of the 

effective date of this AD, in accordance with 

the Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, Revision 1, 

dated December 16, 1983; Revision 2, dated 

April 18, 1986; or Revision 3, dated June 15, 

1989: Within 3,000 flight cycles after the 

effective date of this AD, do a detailed 

inspection for short edge margins. If the short 

edge margin is determined to be less than 

1.5D (diameter), before further flight, do a 

detailed inspection for cracking of the stub 

beam lower chords, in accordance with 

Boeing Service Bulletin 737–53–1061, 

Revision 4, dated July 16, 1992. Repeat the 

detailed inspection thereafter at intervals not 

to exceed 4,500 flight cycles, if the edge 

margin is less than 1.5D. If the edge margin 

is greater than or equal to 1.5D, no further 

action is required by this paragraph. 

Replacing the lower chord in accordance 

with Boeing Service Bulletin 737–53–1061, 

Revision 4, dated July 16, 1992, terminates 

the repetitive inspections specified in this 

paragraph. 

Corrective Actions 

(j) Except as required by paragraph (k) of 

this AD, if any crack or damaged fastener is 

found during any inspection required by this 

AD, before further flight, repair if cracking 

and damaged fasteners are within the 

specified limits, or do a preventive 

modification if cracking or damaged fasteners 

are outside the specified limits, in 

accordance with the Accomplishment 

Instructions of Boeing Service Bulletin 737– 

53–1061, Revision 4, dated July 16, 1992. 

Exception to Service Information 

(k) Where Boeing Service Bulletin 737–53– 

1061, Revision 4, dated July 16, 1992, 

specifies to contact Boeing for repair 

instructions: Before further flight, repair 

using a method approved in accordance with 

the procedures specified in paragraph (n) of 

this AD. 

Terminating Action (Preventive 

Modification) for Certain Inspections 

(l) Before the accumulation of 75,000 total 

flight cycles: Do the preventive modification 

in accordance with Part II, or repair in 

accordance with Part III, of the 

Accomplishment Instructions of Boeing 

Service Bulletin 737–53–1061, Revision 4, 

dated July 16, 1992. The modification or 

repair terminates the repetitive inspection 

requirements of this AD for the repaired or 

modified frame only, except as required by 

paragraph (m) of this AD. 

Post-Modification or Repair Inspections 

(m) For airplanes on which a repair or 

modification at body station 616 or 639 is 

done: Within 24,000 flight cycles after doing 

the repair or modification, or within 3,000 

flight cycles after the effective date of this 

AD, whichever occurs later, do a detailed 

inspection for cracking of the BS 616 and 639 

frame webs, inner chord, and outer chord 

near stringer S–16, in accordance with 

Boeing Service Bulletin 737–53–1061, 

Revision 4, dated July 16, 1992. 

(1) If no cracking is found, repeat the 

inspection thereafter at intervals not to 

exceed 4,500 flight cycles. 

(2) If any cracking is found, before further 

flight, repair the cracking using a method 

approved in accordance with the procedures 

specified in paragraph (n) of this AD. 

Alternative Methods of Compliance 

(AMOCs) 

(n)(1) The Manager, Seattle Aircraft 

Certification Office (ACO), FAA, has the 

authority to approve AMOCs for this AD, if 

requested using the procedures found in 14 

CFR 39.19. Send information to ATTN: 

Wayne Lockett, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue, SW., Renton, Washington 98057– 

3356; telephone (425) 917–6447; fax (425) 

917–6590. Or, e-mail information to 9-ANMSeattle-ACO-AMOC-Requests@faa.gov. 

(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 principal maintenance inspector 

(PMI) or principal avionics inspector (PAI), 

as appropriate, or lacking a principal 

inspector, your local Flight Standards District 

Office. The AMOC approval letter must 

specifically reference this AD. 

(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 


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27972 Federal Register / Vol. 75, No. 96 / Wednesday, May 19, 2010 / Proposed Rules 

Boeing Commercial Airplanes Organization 

Delegation Authorization (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. 

Issued in Renton, Washington, on May 5, 

2010. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2010–11905 Filed 5–18–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2010–0514; Directorate 

Identifier 2010–NE–02–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney JT8D–9, –9A, –11, –15, –17, 

and –17R Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

Pratt & Whitney (PW) JT8D–9, –9A, –11, 

–15, –17, and –17R turbofan engines. 

This proposed AD would require 

overhauling fan blade leading edges at 

the first shop visit after 4,000 cycles-inservice (CIS) since the last total fan 

blade overhaul was performed. This 

proposed AD results from reports of 

failed fan blades. We are proposing this 

AD to prevent high-cycle fatigue 

cracking at the blade root, which could 

result in uncontained failures of first 

stage fan blades and damage to the 

airplane. 

DATES: We must receive any comments 

on this proposed AD by July 19, 2010. 

ADDRESSES: Use one of the following 

addresses to comment on this proposed 

AD. 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov and follow 

the instructions for sending your 

comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 1200 

New Jersey Avenue, SE., West Building 

Ground Floor, Room W12–140, 

Washington, DC 20590–0001. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

• Fax: (202) 493–2251. 

Contact Pratt & Whitney, 400 Main 

St., East Hartford, CT 06108; telephone 

(860) 565–7700; fax (860) 565–1605, for 

a copy of the service information 

identified in this proposed AD. 

FOR FURTHER INFORMATION CONTACT: 

James Gray, Aerospace Engineer, Engine 

Certification Office, FAA, Engine & 

Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; 

e-mail: james.gray@faa.gov; telephone 

(781) 238–7742; fax (781) 238–7199. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send us any written 

relevant data, views, or arguments 

regarding this proposal. Send your 

comments to an address listed under 

ADDRESSES. Include ‘‘Docket No. FAA– 

2010–0514; Directorate Identifier 2010– 

NE–02–AD’’ in the subject line of your 

comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of the proposed AD. We will 

consider all comments received by the 

closing date and may amend the 

proposed AD in light 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 with FAA 

personnel concerning this proposed AD. 

Using the search function of the Web 

site, anyone can find and read the 

comments in any of our dockets, 

including, if provided, the name of the 

individual who sent the comment (or 

signed the comment on behalf of an 

association, business, labor union, etc.). 

You may review the DOT’s complete 

Privacy Act Statement in the Federal 

Register published on April 11, 2000 

(65 FR 19477–78). 

Examining the AD Docket 

You may examine the AD docket on 

the Internet at http:// 

www.regulations.gov; or in person at the 

Docket Operations office 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 the 

same as the Mail address provided in 

the ADDRESSES section. Comments will 

be available in the AD docket shortly 

after receipt. 

Discussion 

We have received reports of 16 first 

stage fan blade root fractures, two of 

which resulted in penetration of the 

cowl and minor damage to the fuselage. 

Engineering investigation has 

determined that increased vibratory 

stress in the root and airfoil from eroded 

and blunt leading edges caused the fan 

blade failures. The primary cause of 

leading edge erosion is the operating 

environment, particularly rain and sand. 

The aerodynamic performance of the 

blade is diminished and vibratory stress 

in the airfoil and root is increased. This 

condition, if not corrected, could result 

in uncontained failures of first stage fan 

blades and damage to the airplane. 

Relevant Service Information 

We have reviewed and approved the 

technical contents of PW JT8D 

Maintenance Advisory Notice MAN– 

JT8D–2–06, dated November 20, 2006, 

that describes procedures for 

overhauling the first stage fan blades at 

every shop visit where pairs of major 

mating flanges are separated. 

FAA’s Determination and Requirements 

of the Proposed AD 

We have evaluated all pertinent 

information and identified an unsafe 

condition that is likely to exist or 

develop on other products of this same 

type design. We are proposing this AD, 

which would require overhauling the 

total set of stage 1 fan blades at: 

• The first shop visit after 4,000 CIS 

since the last total stage 1 fan blade 

overhaul or 

• The next shop visit after the 

effective date of this proposed AD if the 

CIS since the last total stage 1 fan blade 

overhaul is unknown and 

• Thereafter, at the next shop visit 

after 4,000 CIS since the last total stage 

fan blade overhaul. 

The proposed AD would require you 

to use the service information described 

previously to perform these actions. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 1,527 engines installed on 

airplanes of U.S. registry. We also 

estimate that it would take about 63 

work-hours per engine to perform the 

proposed actions, and that the average 

labor rate is $85 per work-hour. There 

would be no required parts. Based on 

these figures, we estimate the total cost 

of the proposed AD to U.S. operators to 

be $8,177,085. 

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 


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