64530 Federal Register / Vol. 69, No. 214 / Friday, November 5, 2004 / Proposed Rules 

in Figure 9 of the service bulletin. 

Completing the initial inspection required by 

this paragraph terminates the repetitive 

inspections required by paragraph (i) of this 

AD. For airplanes on which paragraph (i) of 

this AD has not been done, doing the initial 

inspection required by this paragraph at the 

specified compliance time eliminates the 

need to comply with paragraph (i) of this AD.

TABLE 3.—COMPLIANCE TIMES FOR INITIAL INSPECTION REQUIRED BY PARAGRAPH (L) 

For the inspections identified in the following 

figures referenced in figure 9 of the service bulletin—For these airplanes— Do the inspection—

Figure 10 or 11 ................................................... Airplanes not inspected previously in accordance with paragraph (i) of this AD.Within 15,000 flight cycles after doing the 

modification or permanent repair. 

Figure 10 or 11 ................................................... Airplanes inspected previously in accordance 

with paragraph (i) of this AD using the surface HFEC method for the most recent inspection.

Within 1,000 flight cycles after the most recent inspection. 

Figure 10 or 11 ................................................... Airplanes inspected previously in accordance 

with paragraph (i) of this AD using the 

open-holeHFEC method for the most recent 

inspection.

Within 3,000 flight cycles after the most recent inspection. 

Figure 12 or 13 ................................................... All airplanes ..................................................... Within 6,000 flight cycles after doing the 

modification or permanent repair, or within 

1,000 flight cycles after the effective date of 

this AD, whichever is later. 

Repair 

(m) If any crack is found during any 

inspection required by paragraph (j), (k), or 

(l) of this AD: Before further flight, repair in 

accordance with the Accomplishment 

Instructions of Boeing Service Bulletin 747–

53A2459, Revision 1, dated March 11, 2004; 

except where the service bulletin specifies to 

contact Boeing for appropriate action, repair 

in accordance with a method approved by 

the Manager, Seattle ACO; or in accordance 

with data meeting the type certification basis 

of the airplane approved by a Boeing 

Company DER who has been authorized by 

the Manager, Seattle ACO, to make such 

findings. For a repair method to be approved, 

the approval must specifically reference this 

AD. 

Reporting Not Required 

(n) Although Boeing Service Bulletin 747–

53A2459, Revision 1, dated March 11, 2004, 

specifies to report certain body frame cracks 

on certain airplanes, this AD does not 

include that requirement. 

Alternative Methods of Compliance (AMOCs) 

(o)(1) The Manager, Seattle ACO, has the 

authority to approve AMOCs for this AD, if 

requested using the procedures found in 14 

CFR 39.19. 

(2) An AMOC that provides an acceptable 

level of safety may be used for any repair 

required by this AD, if it is approved by a 

Boeing Company Designated Engineering 

Representative who has been authorized by 

the Manager, Seattle ACO, to make such 

findings. 

(3) AMOCs approved previously in 

accordance with AD 2002–18–04, 

amendment 39–12878, are approved as 

alternative methods of compliance with 

paragraphs (f), (g), (h), and (i) of this AD.

Issued in Renton, Washington, on October 

26, 2004. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service.

[FR Doc. 04–24723 Filed 11–4–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39

[Docket No. FAA–2004–19534; Directorate 

Identifier 2004–NM–99–AD] 

RIN 2120–AA64

Airworthiness Directives; Airbus Model 

A300 B2 and B4 Series Airplanes; 

Model A300 B4–600, B4–600R, and F4–

600R Series Airplanes, and Model A300 

C4–605R Variant F Airplanes 

(Collectively Called A300–600); and 

Model A310 Series Airplanes

AGENCY: Federal Aviation 

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain Airbus airplane models, as 

specified above. This proposed AD 

would require modifying the thermal 

insulation system of certain fuselage 

frames, and modifying the fuselage 

drainage system. This proposed AD 

would also require revising the FAAapproved maintenance inspection 

program to include inspections for 

corrosion or cracking in the subject 

areas. This proposed AD is prompted by 

reports of corrosion in the lower part of 

the pressure bulkhead at certain 

fuselage frames. We are proposing this 

AD to prevent accumulation of 

condensation in the insulation blankets 

of certain fuselage frames, which could 

cause corrosion that could result in 

reduced structural integrity of the 

fuselage and consequent rapid 

decompression of the airplane.

DATES: We must receive comments on 

this proposed AD by December 6, 2004.

ADDRESSES: Use one of the following 

addresses to submit comments on this 

proposed AD. 

• DOT Docket Web Site: Go to

http://dms.dot.gov and follow the 

instructions for sending your comments 

electronically. 

• Government-wide Rulemaking Web 

Site: Go to http://www.regulations.gov

and follow the instructions for sending 

your comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 400 

Seventh Street, SW., Nassif Building, 

room PL–401, Washington, DC 20590. 

• By Fax: (202) 493–2251. 

• Hand Delivery: Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street, SW., 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, 1 

Rond Point Maurice Bellonte, 31707 

Blagnac Cedex, France. 

You can examine the contents of this 

AD docket on the Internet at http://

dms.dot.gov, or in person at the Docket 

Management Facility, U.S. Department 

of Transportation, 400 Seventh Street, 

SW., room PL–401, on the plaza level of 

the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: 

Federal Register / Vol. 69, No. 214 / Friday, November 5, 2004 / Proposed Rules 64531

Technical Information: Dan Rodina, 

Aerospace Engineer, International 

Branch, ANM–116, FAA, Transport 

Airplane Directorate, 1601 Lind 

Avenue, SW., Renton, Washington 

98055–4056; telephone (425) 227–2125; 

fax (425) 227–1149. 

Plain Language Information: Marcia 

Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION: 

Docket Management System (DMS) 

The FAA has implemented new 

procedures for maintaining AD dockets 

electronically. As of May 17, 2004, new 

AD actions are posted on DMS and 

assigned a docket number. We track 

each action and assign a corresponding 

directorate identifier. The DMS AD 

docket number is in the form ‘‘Docket 

No. FAA–2004–99999.’’ The Transport 

Airplane Directorate identifier is in the 

form ‘‘Directorate Identifier 2004–NM–

999–AD.’’ Each DMS AD docket also 

lists the directorate identifier (‘‘Old 

Docket Number’’) as a cross-reference 

for searching purposes. 

Comments Invited 

We invite you to submit any relevant 

written data, views, or arguments 

regarding this proposed AD. Send your 

comments to an address listed under 

ADDRESSES. Include ‘‘Docket No. FAA–

2004–19534; Directorate Identifier 

2004–NM–99–AD’’ at the beginning 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 submitted 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://

dms.dot.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 our docket 

Web site, anyone can find and read the 

comments in any of our dockets, 

including the name of the individual 

who sent the comment (or signed the 

comment on behalf of an association, 

business, labor union, etc.). You can 

review the DOT’s complete Privacy Act 

Statement in the Federal Register

published on April 11, 2000 (65 FR 

19477–78), or you can visit http://

dms.dot.gov.

We are reviewing the writing style we 

currently use in regulatory documents. 

We are interested in your comments on 

whether the style of this document is 

clear, and your suggestions to improve 

the clarity of our communications that 

affect you. You can get more 

information about plain language at 

http://www.faa.gov/language and http://

www.plainlanguage.gov.

Examining the Docket 

You can examine the AD docket on 

the Internet at http://dms.dot.gov, or in 

person at the Docket Management 

Facility office between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. The Docket 

Management Facility office (telephone 

(800) 647–5227) is on the plaza level of 

the Nassif Building at the DOT street 

address stated in the ADDRESSES section. 

Comments will be available in the AD 

docket shortly after the DMS receives 

them. 

Discussion 

The Direction Ge ́ne ́rale de l’Aviation 

Civile (DGAC), which is the 

airworthiness authority for France, 

notified us that an unsafe condition may 

exist on certain Airbus Model A300 B2 

and B4 series airplanes; Model A300 

B4–600, B4–600R, and F4–600R series 

airplanes, and Model A300 C4–605R 

Variant F airplanes (collectively called 

A300–600); and Model A310 series 

airplanes. The DGAC advises that 

corrosion has been found in the lower 

part of the pressure bulkhead at fuselage 

frame (FR) 54 and, on certain airplanes, 

FR 39. Investigation revealed that the 

rear face of FR 54, and the front face of 

FR 39 on certain airplanes, are 

completely thermally insulated; no 

drainage is provided at the insulation 

blankets. The lack of drainage results in 

condensation being trapped. This 

condition, if not corrected, could result 

in corrosion that could result in reduced 

structural integrity of the fuselage and 

consequent rapid decompression of the 

airplane.

Relevant Service Information 

Airbus has issued the service 

bulletins listed in the table below, 

which describe procedures for 

modifying the thermal insulation system 

using the specific procedures identified 

in the table below.

SERVICE BULLETINS FOR MODIFYING THE THERMAL INSULATION SYSTEM

Airbus model Airbus service bulletin Specific procedures described 

A300 B2 and B4 series ..................................... A300–21–0116, Revision 02, dated June 13, 

2003.

Permanently removing insulation blankets 

from the front face of FR 39 and the rear 

face of FR 54 between the cargo compartment floor and the fuselage lower wall and 

removing insulation blankets between FR 

54 and FR 54.1 and stringers 50 through 56 

inclusive on the left and right sides of the 

airplane; installing bracket assemblies to 

raise the blankets in this area; and reinstalling these insulation blankets. 

A300 B4–600, B4–600R, and F4–600R series; 

and A300 C4–605R Variant F (collectively 

called A300–600).

A300–21–6025, Revision 01, dated June 13, 

2003.

Permanently removing insulation blankets 

from the rear face of FR 54 between the 

cargo compartment floor and the fuselage 

lower wall and removing insulation blankets 

between FR 54 and FR 54.1 and stringers 

50 through 56 inclusive on the left and right 

sides of the airplane; installing bracket assemblies to raise the blankets in this area; 

and reinstalling these insulation blankets. 

64532 Federal Register / Vol. 69, No. 214 / Friday, November 5, 2004 / Proposed Rules 

SERVICE BULLETINS FOR MODIFYING THE THERMAL INSULATION SYSTEM—Continued

Airbus model Airbus service bulletin Specific procedures described 

A310 series ........................................................ A310–21–2041, Revision 02, dated June 13, 

2003.

Permanently removing insulation blankets 

from the rear face of FR 54 between the 

cargo compartment floor and the fuselage 

lower wall and removing insulation blankets 

between FR 54 and FR 54.1 and stringers 

50 through 56 inclusive on the left and right 

sides of the airplane; installing bracket assemblies to raise the blankets in this area; 

and reinstalling these insulation blankets 

and testing the additional center fuel tank, if 

installed. 

Airbus has also issued the service 

bulletins listed in the table below, 

which describe procedures for 

modifying the fuselage drainage system 

using the specific procedures identified 

in the table below.

SERVICE BULLETINS FOR MODIFYING THE FUSELAGE DRAINAGE SYSTEM

Airbus model Airbus service bulletin Specific procedures described 

A300 B2 and B4 series ..................................... A300–53–0201, Revision 04, dated May 2, 

2003.

Replacing all existing drain valves in the lower 

fuselage and upper deck cargo door with 

new, improved (plastic) drain valves; installing one additional drain valve; and drilling 

additional drain holes in the stringers. 

A300 B4–600, B4–600R, and F4–600R series; 

and A300 C4–605R Variant F (collectively 

called A300–600).

A300–53–6008, Revision 05, dated July 15, 

2004.

Replacing all existing drain valves in the lower 

fuselage and upper deck cargo door with 

new, improved (plastic) drain valves; installing one additional drain valve; and drilling 

additional drain holes in the stringers. 

A310 series ........................................................ A310–53–2027, Revision 04, dated July 15, 

2004.

Replacing all existing drain valves in the lower 

fuselage with new, improved (plastic) drain 

valves; installing additional drain valves; 

and drilling additional drain holes in the 

stringers. 

Airbus has also issued Maintenance 

Planning Documents containing Task 

Numbers 538295–0603–01 (for Airbus 

Model A300 B2 and B4 series airplanes), 

and 541531–01–1 and 531533–01–1 (for 

Airbus Model A300–600 and Model 

A310 series airplanes). These task 

numbers describe procedures for 

repetitive detailed visual inspections for 

corrosion or cracking of fuselage 

structure from FR 38.2 to 39, and at FR 

54, as applicable. These tasks are 

necessary for airplanes modified in 

accordance with the service information 

described previously. 

Accomplishing the actions specified 

in the applicable service information is 

intended to adequately address the 

unsafe condition. The DGAC mandated 

the service information and issued 

French airworthiness directive 2003–

317(B), dated August 20, 2003, to ensure 

the continued airworthiness of these 

airplanes in France. 

FAA’s Determination and Requirements 

of the Proposed AD

These airplane models are 

manufactured in France and are type 

certificated for operation in the United 

States under the provisions of section 

21.29 of the Federal Aviation 

Regulations (14 CFR 21.29) and the 

applicable bilateral airworthiness 

agreement. Pursuant to this bilateral 

airworthiness agreement, the DGAC has 

kept the FAA informed of the situation 

described above. We have examined the 

DGAC’s findings, evaluated all pertinent 

information, and determined that we 

need to issue an AD for products of this 

type design that are certificated for 

operation in the United States. 

Therefore, we are proposing this AD, 

which would require accomplishing the 

actions specified in the service 

information described previously. This 

proposed AD would also require 

revising the FAA-approved maintenance 

inspection program to include detailed 

inspections for corrosion and cracking 

in the area of FRs 39 and 54, as 

described in the Maintenance Planning 

Document task numbers identified 

previously. 

Differences Between the Proposed AD 

and French Airworthiness Directive 

The applicability of French 

airworthiness directive 2003–317(B) 

excludes airplanes that accomplished 

Airbus Service Bulletin A300–53–0201, 

A300–53–6008, or A310–53–2027 in 

service. However, we have not excluded 

those airplanes in the applicability of 

this proposed AD; rather, this proposed 

AD includes a requirement to 

accomplish the actions specified in 

those service bulletins. This 

requirement would ensure that the 

actions specified in the service bulletins 

and that would be required by this 

proposed AD are accomplished on all 

affected airplanes. Operators must 

continue to operate the airplane in the 

configuration that would be required by 

this proposed AD unless we approve an 

alternative method of compliance. 

French airworthiness directive 2003–

317(B) specifies that airplanes modified 

in accordance with the service 

Federal Register / Vol. 69, No. 214 / Friday, November 5, 2004 / Proposed Rules 64533

information described previously must 

be inspected in accordance with the 

Maintenance Planning Document tasks 

described previously. However, no 

compliance time is given for revising 

the maintenance program. This 

proposed AD would require revising the 

maintenance program to include these 

tasks within 90 days after doing the 

modifications specified in the service 

information described previously, or 

within 90 days after the effective date of 

the AD, whichever is later. We find that 

this represents an appropriate interval 

of time in which this action may be 

accomplished by all affected operators 

without jeopardizing continued flight 

safety. 

Clarification of Inspection Terminology 

In this proposed AD, the ‘‘detailed 

visual inspections’’ specified in 

Maintenance Planning Document Task 

Numbers 538295–0603–01 (for Airbus 

Model A300 B2 and B4 series airplanes), 

and 541531–01–1 and 531533–01–1 (for 

Airbus Model A300 B4–600, B4–600R, 

and F4–600R series airplanes, and A300 

C4–605R Variant F airplanes 

(collectively called A300–600); and 

Model A310 series airplanes), are 

referred to as ‘‘detailed inspections.’’

We have included the definition for a 

detailed inspection in a note in the 

proposed AD. 

Costs of Compliance 

The following table provides the 

estimated costs for U.S. operators to 

comply with this proposed AD, at an 

average labor rate of $65 per work hour.

ESTIMATED COSTS

Action Models Work hours Parts Cost per airplane 

Number of 

U.S.-registered 

airplanes 

Fleet cost 

Modifying the Thermal Insulation System.A300 B2/B4 ........................ 5 $567 $892 23 $20,516

Modifying the Thermal Insulation System.A300 B4–600, B4–600R, 

and F4–600R series; and 

A300 C4–605R Variant F 

(collectively called A300–

600).

4 567 827 116 95,932

Modifying the Thermal Insulation System.A310 ................................... 4 567 827 47 38,869

Modifying the Fuselage 

Drainage System.

A300 B2/B4 ........................ 38 1,857 4,327 23 99,521

Modifying the Fuselage 

Drainage System.

A300 B4–600, B4–600R, 

and F4–600R series; and 

A300 C4–605R Variant F 

(collectively called A300–

600).

36 1,378 3,718 116 431,288

Modifying the Fuselage 

Drainage System.

A310 ................................... 27 1,451 3,206 47 150,682

Maintenance Program Revision.All ........................................ 1 None 65 186 12,090

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. 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, 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–2004–19534; 

Directorate Identifier 2004–NM–99–AD. 

Comments Due Date 

(a) The Federal Aviation Administration 

must receive comments on this AD action by 

December 6, 2004. 

Affected ADs 

(b) None. 

Applicability: (c) This AD applies to Airbus 

Model A300 B2 and B4 series airplanes; 

A300 B4–600, B4–600R, and F4–600R series 

airplanes, and A300 C4–605R Variant F 

airplanes (collectively called A300–600); and 

A310 series airplanes; certificated in any 

category; except those on which Airbus 

Modification 5946 was done during 

production. 

Unsafe Condition 

(d) This AD was prompted by reports of 

corrosion in the lower part of the pressure 

bulkhead at fuselage frames (FR) 39 and 54. 

We are issuing this AD to prevent 

accumulation of condensation in the 

insulation blankets of certain fuselage FRs, 

which could cause corrosion that could 

result in reduced structural integrity of the 

fuselage and consequent rapid 

decompression of the airplane. 

Compliance: (e) You are responsible for 

having the actions required by this AD 

performed within the compliance times 

specified, unless the actions have already 

been done. 

64534 Federal Register / Vol. 69, No. 214 / Friday, November 5, 2004 / Proposed Rules 

Modification of Thermal Insulation and 

Fuselage Drainage Systems 

(f) Within 22 months after the effective 

date of this AD, modify the thermal 

insulation system of applicable fuselage 

frames and modify the fuselage drainage 

system, by doing all actions in the 

Accomplishment Instructions of the 

applicable service bulletins specified in 

Table 1 of this AD.

TABLE 1.—RELEVANT SERVICE BULLETINS

For Airbus models Modify the thermal insulation according to Airbus Service Bulletin 

And modify the fuselage drainage system according to Airbus Service Bulletin 

A300 B2 and B4 series ..................................... A300–21–0116, Revision 02, dated June 13, 

2003.

A300–53–0201, Revision 04, dated May 2, 

2003. 

A300 B4–600, B4–600R, and F4–600R series; 

A300 C4–605R Variant F (collectively called 

A300–600).

A300–21–6025, Revision 01, dated June 13, 

2003.

A300–53–6008, Revision 05, dated July 15, 

2004. 

A310 series ........................................................ A310–21–2041, Revision 02, dated June 13, 

2003.

A310–53–2027, Revision 04, dated July 15, 

2004. 

Modifications Accomplished According to 

Previous Issues of Service Bulletins 

(g) Modifications accomplished before the 

effective date of this AD according to Airbus 

Service Bulletin A300–53–6008, Revision 03, 

dated November 6, 1990, or Revision 04, 

dated April 28, 2003 (for Model A300 B4–

600, B4–600R, and F4–600R series airplanes; 

and A300 C4–605R Variant F airplanes 

(collectively called A300–600)); or Airbus 

Service Bulletin A310–53–2027, Revision 02, 

dated November 6, 1990, or Revision 03, 

dated May 2, 2003 (for Model A310 series 

airplanes); are considered acceptable for 

compliance with the corresponding action 

specified in this AD. 

Maintenance Program Revision 

(h) Within 90 days after doing the actions 

required by paragraph (f) of this AD, or 

within 90 days after the effective date of this 

AD, whichever is later: Incorporate into the 

FAA-approved maintenance inspection 

program repetitive detailed inspections for 

corrosion or cracking of fuselage structure 

from FR 38.2 to 39, and at FR 54, as 

applicable, as described in Airbus 

Maintenance Planning Document Task 

Numbers 538295–0603–01 (for Airbus Model 

A300 B2 and B4 series airplanes), and 

541531–01–1 and 531533–01–1 (for Airbus 

Model A300 B4–600, B4–600R, and F4–600R 

series airplanes, and A300 C4–605R Variant 

F airplanes (collectively called A300–600); 

and Model A310 series airplanes). Then, 

thereafter, comply with the applicable 

requirements.

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.’’

Alternative Methods of Compliance 

(AMOCs) 

(i) The Manager, International Branch, 

ANM–116, Transport Airplane Directorate, 

FAA, has the authority to approve AMOCs 

for this AD, if requested in accordance with 

the procedures found in 14 CFR 39.19. 

Related Information 

(j) French airworthiness directive 2003–

317(B), dated August 20, 2003, also addresses 

the subject of this AD.

Issued in Renton, Washington, on October 

26, 2004. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service.

[FR Doc. 04–24722 Filed 11–4–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39

[Docket No. FAA–2004–19533; Directorate 

Identifier 2004–NM–31–AD] 

RIN 2120–AA64

Airworthiness Directives; Boeing 

Model 737–300, –400, and –500 Series 

Airplanes

AGENCY: Federal Aviation 

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain Boeing Model 737–300, –400, 

and –500 series airplanes. This 

proposed AD would require repetitive 

inspections for cracking of the crown 

area of the fuselage skin, and corrective 

actions, if necessary. This proposed AD 

is prompted by a 737 fuselage structure 

test and fatigue analysis that indicate 

fuselage skin cracking could occur 

between 21,000 and 42,000 total flight 

cycles. We are proposing this AD to 

detect and correct fatigue cracking of the 

fuselage skin, which could cause the 

fuselage skin to fracture and fail, and 

could result in rapid decompression of 

the airplane.

DATES: We must receive comments on 

this proposed AD by December 20, 

2004.

ADDRESSES: Use one of the following 

addresses to submit comments on this 

proposed AD. 

• DOT Docket Web Site: Go to

http://dms.dot.gov and follow the 

instructions for sending your comments 

electronically. 

• Government-wide Rulemaking Web 

Site: Go to http://www.regulations.gov

and follow the instructions for sending 

your comments electronically. 

• Mail: Docket Management Facility, 

U.S. Department of Transportation, 400 

Seventh Street SW., Nassif Building, 

room PL–401, Washington, DC 20590. 

• By Fax: (202) 493–2251. 

• Hand Delivery: Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street SW., 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 Boeing 

Commercial Airplanes, P.O. Box 3707, 

Seattle, Washington 98124–2207. 

You can examine the contents of this 

AD docket on the Internet at http://

dms.dot.gov, or in person at the Docket 

Management Facility, U.S. Department 

of Transportation, 400 Seventh Street 

SW., room PL–401, on the plaza level of 

the Nassif Building, Washington, DC. 

This docket number is FAA–2004–

19533; the directorate identifier for this 

docket is 2004–NM–31–AD.

FOR FURTHER INFORMATION CONTACT:

Technical Information: Sue Lucier, 

Aerospace Engineer, Airframe Branch, 

ANM–120S, FAA, Seattle Aircraft 

Certification Office, 1601 Lind Avenue, 

SW., Renton, Washington 98055–4056; 

telephone (425) 917–6438; fax (425) 

917–6590. 

Plain Language Information: Marcia 

Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION: