57882 Federal Register / Vol. 75, No. 184 / Thursday, September 23, 2010 / Proposed Rules 

Restatement of Requirements of AD 2007– 

02–22, With Revised Service Information 

and Reduced Compliance Time for 

Corrective Action 

Initial and Repetitive Inspections 

(g) Within 2,500 flight cycles after March 

2, 2007 (the effective date of AD 2007–02– 

22): Do a detailed inspection for any missing, 

damaged, or incorrectly installed wiper rings 

in the splined couplings of the flap 

transmission shafts; and a detailed inspection 

for any missing, damaged, or incorrectly 

installed rubber gaiters and straps on the 

sliding bearing/plunging joints of the flap 

transmission; in accordance with the 

Accomplishment Instructions of Airbus 

Service Bulletin A310–27–2099, dated 

February 17, 2006; or Airbus Mandatory 

Service Bulletin A310–27–2099, Revision 01, 

dated March 21, 2008. Repeat the inspections 

thereafter at intervals not to exceed 2,500 

flight cycles. After the effective date of this 

AD, use only Airbus Mandatory Service 

Bulletin A310–27–2099, Revision 01, dated 

March 21, 2008. 

Note 1: For the purposes of this AD, a 

detailed inspection is: ‘‘An intensive 

examination of a specific item, installation, 

or assembly to detect damage, failure, or 

irregularity. Available lighting is normally 

supplemented with a direct source of good 

lighting at an intensity deemed appropriate. 

Inspection aids such as mirror, magnifying 

lenses, etc., may be necessary. Surface 

cleaning and elaborate procedures may be 

required.’’ 

Corrective Actions 

(h) If any damaged, missing or incorrectly 

installed wiper rings, rubber gaiters, or straps 

are found during any inspection required by 

paragraph (g) of this AD: At the applicable 

time in paragraph (h)(1) or (h)(2) of this AD, 

replace the applicable component with a 

serviceable component in accordance with 

the Accomplishment Instructions of Airbus 

Service Bulletin A310–27–2099, dated 

February 17, 2006; or Airbus Mandatory 

Service Bulletin A310–27–2099, Revision 01, 

dated March 21, 2008. After the effective date 

of this AD, use only Airbus Mandatory 

Service Bulletin A310–27–2099, Revision 01, 

dated March 21, 2008. 

(1) For airplanes on which the inspection 

required by paragraph (g) of this AD has been 

done before the effective date of this AD: 

Within 400 flight cycles after accomplishing 

the inspection. 

(2) For airplanes on which the inspection 

required by paragraph (g) of this AD has not 

been done on or after the effective date of this 

AD: Within 400 flight hours after 

accomplishing the inspection required by 

paragraph (g) of this AD. 

New Requirements of This AD 

Actions 

(i) Accomplishment of the actions required 

by paragraph (h) do not terminate the 

repetitive inspections required by paragraph 

(g) of this AD. 

FAA AD Differences 

Note 2: This AD differs from the MCAI 

and/or service information as follows: No 

differences. 

Other FAA AD Provisions 

(j) The following provisions also apply to 

this AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, International 

Branch, Transport Airplane Directorate, 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: 

Dan Rodina, Aerospace Engineer, 

International Branch, ANM–116, Transport 

Airplane Directorate, FAA, 1601 Lind 

Avenue, SW., Renton, Washington 98057– 

3356; telephone (425) 227–2125; fax (425) 

227–1149. 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. AMOCs 

approved previously in accordance with AD 

2007–02–22, Amendment 39–14909, are 

approved as AMOCs for the corresponding 

provisions of paragraphs (g) and (h) of this 

AD. 

(2) Airworthy Product: For any requirement 

in this AD to obtain corrective actions from 

a manufacturer or other source, use these 

actions if they are FAA-approved. Corrective 

actions are considered FAA-approved if they 

are approved by the State of Design Authority 

(or their delegated agent). You are required 

to assure the product is airworthy before it 

is returned to service. 

(3) Reporting Requirements: For any 

reporting requirement in this AD, 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 and has assigned OMB Control 

Number 2120–0056. 

Related Information 

(k) Refer to MCAI European Aviation 

Safety Agency Airworthiness Directive 2006– 

0111R1, dated August 26, 2009; and Airbus 

Mandatory Service Bulletin A310–27–2099, 

Revision 01, dated March 21, 2008; for 

related information. 

Issued in Renton, Washington, on 

September 10, 2010. 

Jeffrey E. Duven, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2010–23738 Filed 9–22–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2010–0855; Directorate 

Identifier 2010–NM–066–AD] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 737–300, –400, and 

–500 Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede an existing airworthiness 

directive (AD) that applies to all Model 

737–300, –400, and –500 series 

airplanes. The existing AD currently 

requires repetitive inspections for 

discrepancies of the fuse pins of the 

inboard and outboard midspar fittings of 

the nacelle strut, and corrective actions 

if necessary. This proposed AD would 

add replacing the midspar fuse pins 

with new, improved fuse pins, which 

would terminate the repetitive 

inspections. This proposed AD results 

from a report of corrosion damage of the 

chrome runout on the head side found 

on all four midspar fuse pins of the 

nacelle strut. Additionally, a large 

portion of the chrome plate was missing 

from the corroded area of the shank. We 

are proposing this AD to prevent 

damage of the fuse pins of the inboard 

and outboard midspar fittings of the 

nacelle strut, which could result in 

reduced structural integrity of the fuse 

pins, and consequent loss of the strut 

and separation of the engine from the 

airplane. 

DATES: We must receive comments on 

this proposed AD by November 8, 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. 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1
Federal Register / Vol. 75, No. 184 / Thursday, September 23, 2010 / Proposed Rules 57883 

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: 

Alan Pohl, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6450; 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–2010–0855; Directorate Identifier 

2010–NM–066–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 

On September 29, 2008, we issued AD 

2008–21–03, amendment 39–15687 (73 

FR 59493, October 9, 2008), for all 

Model 737–300, –400, and –500 series 

airplanes. That AD requires repetitive 

inspections for discrepancies of the fuse 

pins of the inboard and outboard 

midspar fittings of the nacelle strut, and 

corrective actions if necessary. That AD 

resulted from a report of corrosion 

damage of the chrome runout on the 

head side found on all four midspar fuse 

pins of the nacelle strut. Additionally, a 

large portion of the chrome plate was 

missing from the corroded area of the 

shank. We issued that AD to detect and 

correct discrepancies of the fuse pins of 

the inboard and outboard midspar 

fittings of the nacelle strut, which could 

result in reduced structural integrity of 

the fuse pins, and consequent loss of the 

strut and separation of the engine from 

the airplane. 

Actions Since Existing AD Was Issued 

In the preamble to the NPRM of AD 

2008–21–03, the FAA specified that the 

actions required by that AD were 

considered ‘‘interim action’’ and that the 

manufacturer was developing a 

modification to address the unsafe 

condition. The FAA indicated that it 

may consider further rulemaking action 

once the modification was developed, 

approved, and available. The 

manufacturer now has developed such a 

modification, and the FAA has 

determined that further rulemaking 

action is indeed necessary; this 

proposed AD follows from that 

determination. 

Relevant Service Information 

We have reviewed Boeing Alert 

Service Bulletin 737–54A1044, Revision 

2, dated January 20, 2010. The repetitive 

detailed inspections and corrective 

actions are similar to those described in 

Boeing Special Attention Service 

Bulletin 737–54–1044, dated December 

10, 2007 (referenced in AD 2008–21–03 

as the appropriate source of service 

information). Revision 2 of the service 

bulletin adds procedures for replacing 

the midspar fuse pins with new, 

improved fuse pins. Replacement with 

the new, improved fuse pin eliminates 

the need for repetitive detailed 

inspections. 

FAA’s Determination and Requirements 

of the Proposed AD 

We have evaluated all pertinent 

information and identified an unsafe 

condition that is likely to develop on 

other airplanes of the same type design. 

For this reason, we are proposing this 

AD, which would supersede AD 2008– 

21–03 and would retain the 

requirements of the existing AD. This 

proposed AD would also require 

replacing the midspar fuse pins with 

new, improved fuse pins, which would 

terminate the requirement for repetitive 

detailed inspections. 

Change to Existing AD 

This proposed AD would retain all 

requirements of AD 2008–21–03. Since 

AD 2008–21–03 was issued, the AD 

format has been revised, and certain 

paragraphs have been rearranged. As a 

result, paragraph (f) of the existing AD 

has been re-identified as paragraph (g) 

in this NPRM. 

Costs of Compliance 

There are about 1,961 airplanes of the 

affected design in the worldwide fleet. 

The following table provides the 

estimated costs for U.S. operators to 

comply with this proposed AD. 

ESTIMATED COSTS

Action Work hours Average labor 

rate per hour Parts Cost per airplane 

Number of 

U.S.- 

registered 

airplanes 

Fleet cost 

Repetitive detailed inspections (required 

by AD 2008–21–03).

4 ................................. $85 None ........ $340, per inspection 

cycle.

616 $209,440, per inspection cycle. 

Midspar fuse pin replacement (new proposed action).1 per pin (up to 4 pins 

per airplane).

85 $843 per 

pin.

Up to $3,712 .............. 616 Up to $2,286,592. 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1
57884 Federal Register / Vol. 75, No. 184 / Thursday, September 23, 2010 / Proposed Rules 

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 have 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 that the 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. 

We prepared a regulatory evaluation 

of the estimated costs to comply with 

this proposed AD and placed it in the 

AD docket. See the ADDRESSES section 

for a location to examine the regulatory 

evaluation. 

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 

removing amendment 39–15687 (73 FR 

59493, October 9, 2008) and adding the 

following new AD: 

The Boeing Company: Docket No. FAA– 

2010–0855; Directorate Identifier 2010– 

NM–066–AD. 

Comments Due Date 

(a) The FAA must receive comments on 

this AD action by November 8, 2010. 

Affected ADs 

(b) This AD supersedes AD 2008–21–03, 

Amendment 39–15687. 

Applicability 

(c) This AD applies to all The Boeing 

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

series airplanes, certificated in any category. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 54: Nacelles/Pylons. 

Unsafe Condition 

(e) This AD results from a report of 

corrosion damage of the chrome runout on 

the head side found on all four midspar fuse 

pins of the nacelle strut. Additionally, a large 

portion of the chrome plate was missing from 

the corroded area of the shank. The Federal 

Aviation Administration is issuing this AD to 

prevent damage of the fuse pins of the 

inboard and outboard midspar fittings of the 

nacelle strut, which could result in reduced 

structural integrity of the fuse pins, and 

consequent loss of the strut and separation of 

the engine from the airplane. 

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. 

Restatement of Requirements of AD 2008– 

21–03 

Repetitive Inspections/Corrective Actions, 

With Revised Service Information 

(g) At the applicable time specified in 

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

Special Attention Service Bulletin 737–54– 

1044, dated December 10, 2007; except, 

where the service bulletin specifies a 

compliance time after the date on the service 

bulletin, this AD requires compliance within 

the specified compliance time after 

November 13, 2008 (the effective date of AD 

2008–21–03): Do a detailed inspection for 

discrepancies of the fuse pins of the inboard 

and outboard midspar fittings of the nacelle 

strut by doing all the actions, including all 

applicable corrective actions, in accordance 

with the Accomplishment Instructions of 

Boeing Special Attention Service Bulletin 

737–54–1044, dated December 10, 2007; or 

Boeing Alert Service Bulletin 737–54A1044, 

Revision 2, dated January 20, 2010. Do all 

applicable corrective actions before further 

flight. Repeat the inspection at the time 

specified in paragraph 1.E. of Boeing Special 

Attention Service Bulletin 737–54–1044, 

dated December 10, 2007. Accomplishing the 

actions of paragraph (h) of this AD terminates 

the requirements of this paragraph. 

New Requirements of This AD 

Replacement 

(h) Within 120 months after the effective 

date of this AD, replace all midspar fuse pins 

having part number (P/N) 311A1092–2 with 

a midspar fuse pin having P/N 311A1092–3, 

in accordance with the Accomplishment 

Instructions of Boeing Alert Service Bulletin 

737–54A1044, Revision 2, dated January 20, 

2010. Accomplishing the requirements of this 

paragraph terminates the requirements of 

paragraph (g) of this AD for that fuse pin. 

Actions Accomplished According to 

Previous Revision of Service Information 

(i) Actions done before the effective date of 

this AD in accordance with Boeing Special 

Attention Service Bulletin 737–54–1044, 

Revision 1, dated November 26, 2008, are 

acceptable for compliance with the 

corresponding requirements of this AD. 

Alternative Methods of Compliance 

(AMOCs) 

(j)(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: Alan 

Pohl, Aerospace Engineer, Airframe Branch, 

ANM–120S, FAA, Seattle Aircraft 

Certification Office, 1601 Lind Avenue, SW., 

Renton, Washington 98057–3356; telephone 

(425) 917–6450; fax (425) 917–6590. 

Information may be e-mailed 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 

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 in accordance with 

the requirements of AD 2008–21–03 are 

acceptable for the corresponding 

requirements of this AD. 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1
Federal Register / Vol. 75, No. 184 / Thursday, September 23, 2010 / Proposed Rules 57885 

Issued in Renton, Washington, on 

September 15, 2010. 

Robert D. Breneman, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2010–23841 Filed 9–22–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2010–0856; Directorate 

Identifier 2010–NM–117–AD] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 737–600, –700, –700C, 

–800, and –900 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 737–600, –700, –700C, –800, and 

–900 series airplanes. This proposed AD 

would require inspecting for part 

numbers of the operational program 

software of the flight control computers, 

and doing corrective actions if 

necessary. This proposed AD results 

from reports of erroneous undetected 

output from a single radio altimeter 

channel, which resulted in premature 

autothrottle retard during approach. We 

are proposing this AD to detect and 

correct erroneous output from a radio 

altimeter channel, which could result in 

premature autothrottle landing flare 

retard and the loss of automatic speed 

control, and consequent loss of control 

of the airplane. 

DATES: We must receive comments on 

this proposed AD by November 8, 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: 

Richard Reed, Aerospace Engineer, 

Systems and Equipment Branch, ANM– 

130S, FAA, Seattle Aircraft Certification 

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

Renton, Washington 98057–3356; 

telephone (425) 917–6431; 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–2010–0856; Directorate Identifier 

2010–NM–117–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 a number 

of instances in service, of erroneous 

undetected output from a single radio 

altimeter channel, which resulted in 

premature autothrottle retard during 

approach. This condition can lead to 

premature autothrottle landing flare 

retard and the loss of automatic speed 

control, and consequent loss of control 

of the airplane. 

Relevant Service Information 

We have reviewed Boeing Alert 

Service Bulletin 737–22A1211, dated 

April 13, 2010, which describes 

procedures for inspecting to determine 

the operational program software part 

numbers of the flight control computers, 

and installing new software if necessary. 

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 these same 

type designs. This proposed AD would 

require accomplishing the actions 

specified in the service information 

described previously. 

Costs of Compliance 

We estimate that this proposed AD 

would affect 207 airplanes of U.S. 

registry. We also estimate that it would 

take about 1 work-hour per product to 

comply with the inspection of this 

proposed AD. The average labor rate is 

$85 per work-hour. Based on these 

figures, we estimate the cost of the 

inspection of this proposed AD to the 

U.S. operators to be $17,595, or $85 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 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1