28632 Federal Register / Vol. 76, No. 96 / Wednesday, May 18, 2011 / Rules and Regulations 

Alternative Methods of Compliance 

(AMOCs) 

(n)(1) The Manager, Atlanta ACO, 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 manager of the ACO, send it 

to the attention of the person identified in the 

Related Information section of this AD. 

(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. 

Related Information 

(o) For more information about this AD, 

contact Carl Gray, Aerospace Engineer, 

Airframe Branch, ACE–117A, FAA, Atlanta 

Aircraft Certification Office, 1701 Columbia 

Avenue, College Park, GA 30337; phone: 

(404) 474–5554; fax: (404) 474–5606; e-mail: 

Carl.W.Gray@faa.gov. 

Material Incorporated by Reference 

(p) You must use Lockheed Service 

Bulletin 382–57–85 (82–790), Revision 2, 

dated August 23, 2007, including 

Appendixes A, B, C, D, E, F, and G, all 

Revision 1, all dated March 8, 2007, to do the 

actions required by this AD, unless the AD 

specifies otherwise. 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

Lockheed Service Bulletin 382–57–85 (82– 

790), Revision 2, dated August 23, 2007, 

including Appendixes A, B, C, D, E, F, and 

G, all Revision 1, all dated March 8, 2007, 

under 5 U.S.C. 552(a) and 1 CFR part 51. 

(2) For service information identified in 

this AD, contact Lockheed Martin 

Corporation/Lockheed Martin Aeronautics 

Company, Airworthiness Office, Dept. 6A0M, 

Zone 0252, Column P–58, 86 S. Cobb Drive, 

Marietta, Georgia 30063; telephone 770–494– 

5444; fax 770–494–5445; e-mail 

ams.portal@lmco.com; Internet http:// 

www.lockheedmartin.com/ams/tools/ 

TechPubs.html. 

(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 April 12, 

2011. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2011–11900 Filed 5–17–11; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–0348; Directorate 

Identifier 2011–NM–069–AD; Amendment 

39–16701; AD 2011–08–51] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 737–300, –400, and 

–500 Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; request for 

comments. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for the 

products listed above. This emergency 

AD was sent previously to all known 

U.S. owners and operators of these 

airplanes. This AD requires repetitive 

external eddy current inspections of the 

lap joints at stringers S–4R and S–4L, 

along the entire length from body 

station (BS) 360 to BS 908. If a crack 

indication is found, the AD requires 

either confirming the crack by doing 

internal eddy current inspections, or 

repairing the crack. As an alternative to 

the external eddy current inspections, 

the AD provides for internal eddy 

current and detailed inspections for 

cracks in the lower skin at the lower 

row of fasteners at stringers S–4L and S– 

4R. This AD was prompted by a report 

indicating that a Model 737–300 series 

airplane experienced a rapid 

decompression when the lap joint at 

stringer S–4L between BS 664 and BS 

727 cracked and opened up due to 

cracking in the lower skin at the lower 

row of fasteners. We are issuing this AD 

to detect and correct such cracking, 

which could result in an uncontrolled 

decompression of the airplane. 

DATES: This AD is effective June 2, 2011 

to all persons except those persons to 

whom it was made immediately 

effective by Emergency AD 2011–08–51, 

issued on April 5, 2011, which 

contained the requirements of this 

amendment. 

The Director of the Federal Register 

approved the incorporation by reference 

of certain publications identified in the 

AD as of June 2, 2011. 

We must receive comments on this 

AD by July 5, 2011. 

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: 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 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. 

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 AD, the regulatory 

evaluation, any comments received, and 

other information. The street address for 

the Docket Operations 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: 

Wayne Lockett, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office 

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

Washington 98057–3356; phone: 425– 

917–6447; fax: 425–917–6590; e-mail: 

wayne.lockett@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

On April 5, 2011, we issued 

Emergency AD 2011–08–51, which 

requires repetitive external eddy current 

inspections of the lap joints at stringers 

S–4R and S–4L, along the entire length 

from body station (BS) 360 to BS 908. 

If a crack indication is found, the AD 

requires either confirming the crack by 

doing internal eddy current inspections, 

or repairing the crack. As an alternative 

to the external eddy current inspections, 

the AD provides for internal eddy 

current and detailed inspections for 

cracks in the lower skin at the lower 

row of fasteners at stringers S–4L and 

S–4R. This action was prompted by a 

report indicating that a Model 737–300 

series airplane experienced a rapid 

decompression when the lap joint at 

stringer S–4L between BS 664 and BS 

727 cracked and opened up due to 

cracking in the lower skin at the lower 

row of fasteners. The airplane had 

accumulated 39,781 total flight cycles 


wwoods2 on DSK1DXX6B1PROD with RULES_PART 1
Federal Register / Vol. 76, No. 96 / Wednesday, May 18, 2011 / Rules and Regulations 28633 

and 48,740 total flight hours. Such 

cracking, if not corrected, could result 

in an uncontrolled decompression of the 

airplane. 

Relevant Service Information 

We reviewed Boeing Alert Service 

Bulletin 737–53A1319, dated April 4, 

2011. That service bulletin describes 

procedures for external eddy current 

inspections of the lap joints at stringers 

S–4R and S–4L, along the entire length 

from BS 360 to BS 908. If a crack 

indication is found, that service bulletin 

specifies either confirming the crack by 

doing internal eddy current inspections, 

or repairing the crack. As an alternative 

to the external eddy current inspections, 

that service bulletin provides 

procedures for internal eddy current 

and detailed inspections for cracks in 

the lower skin at the lower row of 

fasteners at stringers S–4L and S–4R. 

That service bulletin specifies 

contacting Boeing for crack repair 

instructions. 

Since we issued the emergency AD, 

we have approved Revision 1 of this 

service bulletin as an alternative method 

of compliance (AMOC) with certain 

requirements of emergency AD 2011– 

08–51. We have added paragraph (l)(4) 

to this AD to provide information on 

this approved AMOC. 

FAA’s Determination 

We are issuing this AD because we 

evaluated all the relevant information 

and determined the unsafe condition 

described previously is likely to exist or 

develop in other products of these same 

type designs. 

AD Requirements 

This AD requires accomplishing the 

actions specified in the service 

information described previously, 

except as discussed under ‘‘Differences 

Between the AD and the Service 

Information.’’ 

Differences Between the AD and the 

Service Information 

That service bulletin specifies to 

contact the manufacturer for 

instructions on how to repair certain 

conditions, but this AD requires 

repairing those conditions in one of the 

following ways: 

• In accordance with 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 

Designation Authorization (ODA) whom 

we have authorized to make those 

findings. 

FAA’s Determination of the Effective 

Date 

An unsafe condition exists that 

requires the immediate adoption of this 

AD. The FAA has found that the risk to 

the flying public justifies waiving notice 

and comment prior to adoption of this 

rule because cracking in the lower skin 

at the lower row of fasteners of the lap 

joints at stringers S–4R and S–4L, along 

the entire length from BS 360 to BS 908, 

could open up and result in an 

uncontrolled decompression of the 

airplane. Therefore, we find that notice 

and opportunity for prior public 

comment are impracticable and that 

good cause exists for making this 

amendment effective in less than 

30 days. 

Comments Invited 

This AD is a final rule that involves 

requirements affecting flight safety and 

was not preceded by notice and an 

opportunity for public comment. 

However, we invite you to send any 

written data, views, or arguments about 

this AD. Send your comments to an 

address listed under the ADDRESSES

section. Include the docket number 

FAA–2011–0348 and Directorate 

Identifier 2011–NM–069–AD at the 

beginning of your comments. We 

specifically invite comments on the 

overall regulatory, economic, 

environmental, and energy aspects of 

this AD. We will consider all comments 

received by the closing date and may 

amend this 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 AD. 

Costs of Compliance 

We estimate that this AD affects 195 

airplanes of U.S. registry. We estimate 

the following costs to comply with this 

AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per product Cost on U.S. operators 

Inspections .... 6 or 15 work-hours (depending on 

inspection method) × $85 per 

work-hour.

None ............ $510 or $1,275 per inspection cycle $99,450 or $248,625 per inspection 

cycle. 

We have received no definitive data 

that would enable us to provide a cost 

estimate for the on-condition actions 

(confirming crack indications and 

repairing cracks) 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 

This AD will not have federalism 

implications under Executive Order 

13132. This AD will not have a 

substantial direct effect on the States, on 

the relationship between the national 

government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify that this AD: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866, 

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

DOT Regulatory Policies and Procedures 

(44 FR 11034, February 26, 1979), 

(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 


wwoods2 on DSK1DXX6B1PROD with RULES_PART 1
28634 Federal Register / Vol. 76, No. 96 / Wednesday, May 18, 2011 / Rules and Regulations 

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): 

2011–08–51 The Boeing Company: 

Amendment 39–16701; Docket No. 

FAA–2011–0348; Directorate Identifier 

2011–NM–069–AD. 

Effective Date 

(a) This AD is effective June 2, 2011 to all 

persons except those persons to whom it was 

made immediately effective by Emergency 

AD 2011–08–51, issued on April 5, 2011, 

which contained the requirements of this 

amendment. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to The Boeing 

Company Model 737–300, –400, and –500 

series airplanes, certificated in any category, 

as identified in Boeing Alert Service Bulletin 

737–53A1319, dated April 4, 2011. 

Subject 

(d) Joint Aircraft System Component 

(JASC)/Air Transport Association (ATA) of 

America Code 53: Fuselage. 

Unsafe Condition 

(e) This AD was prompted by a report 

indicating that a Model 737–300 series 

airplane experienced a rapid decompression 

when the lap joint at stringer S–4L between 

body station (BS) 664 and BS 727 cracked 

and opened up due to cracking in the lower 

skin at the lower row of fasteners. We are 

issuing this AD to detect and correct such 

cracking, which could result in an 

uncontrolled decompression of the airplane. 

Compliance 

(f) Comply with this AD within the 

compliance times specified, unless already 

done. 

Inspections 

(g) At the applicable time specified in 

paragraph (g)(1), (g)(2), or (g)(3) of this AD: 

Except as provided by paragraphs (h) and (i) 

of this AD, do external eddy current 

inspections of the lap joint at stringers S–4R 

and S–4L, along the entire length from body 

station (BS) 360 to BS 908, in accordance 

with the Accomplishment Instructions of 

Boeing Alert Service Bulletin 737–53A1319, 

dated April 4, 2011. If any crack indication 

is detected, before further flight, either 

confirm the crack indication by doing eddy 

current inspections from the interior of the 

fuselage in the lower skin at the lower row 

of fasteners at stringer S–4L and S–4R, in 

accordance with Boeing Alert Service 

Bulletin 737–53A1319, dated April 4, 2011, 

or repair in accordance with paragraph (j) of 

this AD. 

(1) For airplanes that have accumulated 

fewer than 30,000 total flight cycles as of the 

effective date of this AD: Inspect before the 

accumulation of 30,000 total flight cycles, or 

within 20 days after the effective date of this 

AD, whichever occurs later. 

(2) For airplanes that have accumulated 

30,000 or more total flight cycles and fewer 

than 35,000 total flight cycles as of the 

effective date of this AD: Inspect within 20 

days after the effective date of this AD. 

(3) For airplanes that have accumulated 

35,000 total flight cycles or more as of the 

effective date of this AD: Inspect within 5 

days after the effective date of this AD. 

(h) For areas repaired with external 

doublers, paragraphs (h)(1) and (h)(2) of this 

AD apply. 

(1) If the repair meets the criteria specified 

in paragraphs 3.B.1.c.(1) and 3.B.1.c.(2) of 

Boeing Alert Service Bulletin 737–53A1319, 

dated April 4, 2011, no inspection of the 

lower skin at the lap joint lower fastener row 

is required under the doubler. 

(2) If the repair does not meet the criteria 

specified in paragraphs 3.B.1.c.(1) and 

3.B.1.c.(2) of Boeing Alert Service Bulletin 

737–53A1319, dated April 4, 2011, inspect 

the lower skin lap joint lower row internally 

in the area covered by the doubler, in 

accordance with Boeing Alert Service 

Bulletin 737–53A1319, dated April 4, 2011. 

(i) The inspections required by paragraph 

(g) of this AD may alternatively be done by 

internal eddy current and detailed 

inspections for cracks in the lower skin at the 

lower row of fasteners at stringer S–4L and 

S–4R, along the entire length from BS 360 to 

BS 908, in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–53A1319, dated April 4, 

2011. 

(j) If any crack is found during any 

inspection required by this AD: Before 

further flight, repair the crack using a method 

approved in accordance with the procedures 

specified in paragraph (l) of this AD. 

(k) Repeat the inspections specified in 

either paragraph (g) or (i) of this AD 

thereafter at intervals not to exceed 500 flight 

cycles. Either inspection method may be 

used at any repetitive inspection cycle. 

Alternative Methods of Compliance 

(AMOCs) 

(l)(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. 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 manager of the ACO, send it to the 

attention of the person identified in the 

Related Information section of this AD. 

Information may be e-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 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, and the 

approval must specifically refer to this AD. 

(4) AMOCs approved for emergency AD 

2011–08–51 are approved as AMOCs for the 

corresponding requirements of this AD. 

Related Information 

(m)(1) For further information about this 

AD, contact Wayne Lockett, Aerospace 

Engineer, Airframe Branch, ANM–120S, 

FAA, Seattle Aircraft Certification Office 

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

Washington 98057–3356; phone: 425–917– 

6447; fax: 425–917–6590; e-mail: 

wayne.lockett@faa.gov. 

(2) For copies of the service information 

referenced 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; 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. 

Material Incorporated by Reference 

(n) You must use Boeing Alert Service 

Bulletin 737–53A1319, dated April 4, 2011, 

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; e-mail 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 


wwoods2 on DSK1DXX6B1PROD with RULES_PART 1
Federal Register / Vol. 76, No. 96 / Wednesday, May 18, 2011 / Rules and Regulations 28635 

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 May 6, 

2011. 

Kalene C. Yanamura, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2011–11928 Filed 5–17–11; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2011–0230; Directorate 

Identifier 2011–CE–004–AD; Amendment 

39–16699; AD 2011–11–01] 

RIN 2120–AA64 

Airworthiness Directives; British 

Aerospace Regional Aircraft Model 

HP.137 Jetstream Mk.1, Jetstream 

Series 200, Jetstream Series 3101, and 

Jetstream Model 3201 Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for the 

products listed above. This AD results 

from mandatory continuing 

airworthiness information (MCAI) 

issued by an aviation authority of 

another country to identify and correct 

an unsafe condition on an aviation 

product. The MCAI describes the unsafe 

condition as: 

As a result of fatigue-testing programme on 

Jetstream aeroplanes, cracks have been found 

on the main landing gear (MLG) fittings that 

embody modifications JM5218 or JM8003. 

This condition, if not detected and 

corrected, could lead to a MLG collapse on 

the ground or during landing, possibly 

resulting in a fuel tank rupture, consequent 

damage to the aeroplane or injury to the 

occupants. 

We are issuing this AD to require 

actions to correct the unsafe condition 

on these products. 

DATES: This AD becomes effective June 

22, 2011. 

On June 22, 2011, the Director of the 

Federal Register approved the 

incorporation by reference of a certain 

publication listed in this AD. 

ADDRESSES: You may examine the AD 

docket on the Internet at http:// 

www.regulations.gov or in person at 

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 service information identified in 

this AD, contact BAE Systems 

(Operations) Ltd, Customer Information 

Department, Prestwick International 

Airport, Ayrshire, KA9 2RW, Scotland, 

United Kingdom; phone: +44 1292 

675207, fax: +44 1292 675704; Internet: 

http://www.baesystems.com/ 

WorldWideLocations/UK/. E-mail: 

RApublications@baesystems.com. You 

may review copies of the referenced 

service information at the FAA, Small 

Airplane Directorate, 901 Locust, 

Kansas City, Missouri 64106. For 

information on the availability of this 

material at the FAA, call (816) 329– 

4148. 

FOR FURTHER INFORMATION CONTACT: 

Taylor Martin, Aerospace Engineer, 

FAA, Small Airplane Directorate, 901 

Locust, Room 301, Kansas City, 

Missouri 64106; telephone: (816) 329– 

4138; fax: (816) 329–4090; e-mail: 

taylor.martin@faa.gov. 

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 March 16, 2011 (76 FR 

14349). That NPRM proposed to correct 

an unsafe condition for the specified 

products. The MCAI states: 

As a result of fatigue-testing programme on 

Jetstream aeroplanes, cracks have been found 

on the main landing gear (MLG) fittings that 

embody modifications JM5218 or JM8003. 

This condition, if not detected and 

corrected, could lead to a MLG collapse on 

the ground or during landing, possibly 

resulting in a fuel tank rupture, consequent 

damage to the aeroplane or injury to the 

occupants. 

Analysis of this failure indicates that an 

inspection regime has to be implemented in 

order to ensure the safe operation of the MLG 

beyond the accumulation of 41,000 Flight 

Cycles (FC). 

For the reasons described above, this AD 

requires initial and repetitive eddy current 

inspections, and depending on findings, 

accomplishment of corrective actions. 

The MCAI requires replacing or 

repairing any cracked MLG fitting found 

during the initial and repetitive 

inspections. 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 

received no comments on the NPRM or 

on the determination of the cost to the 

public. 

Conclusion 

We reviewed the available data and 

determined that air safety and the 

public interest require adopting the AD 

as proposed. 

Differences Between This AD and the 

MCAI or Service Information 

We have reviewed the MCAI and 

related service information and, in 

general, agree with their substance. But 

we might have found it necessary to use 

different words from those in the MCAI 

to ensure the AD is clear for U.S. 

operators and is enforceable. In making 

these changes, we do not intend to differ 

substantively from the information 

provided in the MCAI and related 

service information. 

We might also have required different 

actions in this AD from those in the 

MCAI in order to follow FAA policies. 

Any such differences are highlighted in 

a Note within the AD. 

Costs of Compliance 

We estimate that this AD will affect 

190 products of U.S. registry. We also 

estimate that it will take about 20 workhours per product to comply with the 

basic requirements of this AD. The 

average labor rate is $85 per work-hour. 

Based on these figures, we estimate 

the cost of this AD on U.S. operators to 

be $323,000 or $1,700 per product. 

In addition, we estimate that any 

necessary follow-on actions will take 

about 4 work-hours and require parts 

costing $8,000, for a cost of $8,340 per 

product. We have no way of 

determining the number of products 

that may need these actions. 

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 


wwoods2 on DSK1DXX6B1PROD with RULES_PART 1