Federal Register / Vol. 70, No. 162 / Tuesday, August 23, 2005 / Proposed Rules 49207

Government of the exporting region’’

would be added in their place. 

d. In paragraph (c)(4), the words 

‘‘Government of Mexico’’ would be 

removed and the words ‘‘national 

Government of the exporting region’’

would be added in their place.

Done in Washington, DC, this 17th day of 

August 2005. 

Elizabeth E. Gaston, 

Acting Administrator, Animal and Plant 

Health Inspection Service.

[FR Doc. 05–16689 Filed 8–22–05; 8:45 am] 

BILLING CODE 3410–34–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39

[Docket No. 2001–NM–213–AD] 

RIN 2120–AA64

Airworthiness Directives; Boeing 

Model 747SP, 747SR, 747–100, –100B, 

–100B SUD, –200B, –200C, –200F, and 

–300 Series Airplanes

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT).

ACTION: Supplemental notice of 

proposed rulemaking; reopening of 

comment period. 

SUMMARY: This document revises an 

earlier proposed airworthiness directive 

(AD), applicable to all Boeing Model 

747SP, 747SR, 747–100, –100B, –100B 

SUD, –200B, –200C, –200F, and –300 

series airplanes, that would have 

required modification of the escape 

slide/raft pack assembly and cable 

release sliders. This new action revises 

the proposed rule by incorporating new 

service information, which clarifies the 

airplanes on which certain actions must 

be done, and by adding a new 

requirement for certain airplanes. The 

actions specified by this new proposed 

AD are intended to prevent improper 

deployment of the escape slide/raft or 

blockage of the passenger/crew doors in 

the event of an emergency evacuation, 

which could result in injury to 

passengers or crewmembers. This action 

is intended to address the identified 

unsafe condition.

DATES: Comments must be received by 

September 19, 2005.

ADDRESSES: Submit comments in 

triplicate to the Federal Aviation 

Administration (FAA), Transport 

Airplane Directorate, ANM–114, 

Attention: Rules Docket No. 2001–NM–

213–AD, 1601 Lind Avenue, SW., 

Renton, Washington 98055–4056. 

Comments may be inspected at this 

location between 9 a.m. and 3 p.m., 

Monday through Friday, except Federal 

holidays. Comments may be submitted 

via fax to (425) 227–1232. Comments 

may also be sent via the Internet using 

the following address: 9-anmnprmcomment@faa.gov. Comments sent 

via fax or the Internet must contain 

‘‘Docket No. 2001–NM–213–AD’’ in the 

subject line and need not be submitted 

in triplicate. Comments sent via the 

Internet as attached electronic files must 

be formatted in Microsoft Word 97 or 

2000 or ASCII text. 

The service information referenced in 

the proposed rule may be obtained from 

Boeing Commercial Airplanes, P.O. Box 

3707, Seattle, Washington 98124–2207. 

This information may be examined at 

the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue, SW., 

Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Keith Ladderud, Aerospace Engineer, 

Cabin Safety and Environmental 

Systems Branch, ANM–150S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98055–4056; telephone 

(425) 917–6435; fax (425) 917–6590.

SUPPLEMENTARY INFORMATION: 

Comments Invited 

Interested persons are invited to 

participate in the making of the 

proposed rule by submitting such 

written data, views, or arguments as 

they may desire. Communications shall 

identify the Rules Docket number and 

be submitted in triplicate to the address 

specified above. All communications 

received on or before the closing date 

for comments, specified above, will be 

considered before taking action on the 

proposed rule. The proposals contained 

in this action may be changed in light 

of the comments received. 

Submit comments using the following 

format:

• Organize comments issue-by-issue. 

For example, discuss a request to 

change the compliance time and a 

request to change the service bulletin 

reference as two separate issues. 

• For each issue, state what specific 

change to the proposed AD is being 

requested. 

• Include justification (e.g., reasons or 

data) for each request. 

Comments are specifically invited on 

the overall regulatory, economic, 

environmental, and energy aspects of 

the proposed rule. All comments 

submitted will be available, both before 

and after the closing date for comments, 

in the Rules Docket for examination by 

interested persons. A report 

summarizing each FAA-public contact 

concerned with the substance of this 

proposal will be filed in the Rules 

Docket. 

Commenters wishing the FAA to 

acknowledge receipt of their comments 

submitted in response to this action 

must submit a self-addressed, stamped 

postcard on which the following 

statement is made: ‘‘Comments to 

Docket Number 2001–NM–213–AD.’’

The postcard will be date stamped and 

returned to the commenter. 

Availability of NPRMs 

Any person may obtain a copy of this 

NPRM by submitting a request to the 

FAA, Transport Airplane Directorate, 

ANM–114, Attention: Rules Docket No. 

2001–NM–213–AD, 1601 Lind Avenue, 

SW., Renton, Washington 98055–4056. 

Discussion 

A proposal to amend part 39 of the 

Federal Aviation Regulations (14 CFR 

part 39) to add an airworthiness 

directive (AD), applicable to all Boeing 

Model 747SP, 747SR, 747–100, –100B, 

–100B SUD, –200B, –200C, –200F, and 

–300 series airplanes, was published as 

a notice of proposed rulemaking 

(NPRM) (hereafter referred to as the 

‘‘original NPRM’’) in the Federal 

Register on September 10, 2003 (68 FR 

53309). That NPRM would have 

required modification of the escape 

slide/raft pack assembly and cable 

release sliders. The original NPRM was 

prompted by improper escape slide/raft 

deployment and passenger/crew door 

blockage during slide deployment tests. 

That condition, if not corrected, could 

result in injury to passengers or 

crewmembers. 

Comments 

Due consideration has been given to 

the comments received in response to 

the original NPRM. 

Request To Change Preamble/Add 

Revised Service Information 

One commenter asks that Boeing 

Special Attention Service Bulletin 747–

25–3274, Revision 2, dated August 26, 

2004, be added to the first paragraph of 

the ‘‘Explanation of Relevant Service 

Information’’ section of the original 

NPRM. Revision 1 of the service bulletin 

was referenced in the original NPRM as 

the source of service information for 

modifying the slide/raft pack assembly. 

The commenter also asks that the 

following be added to that paragraph: 

‘‘Note: Revision 2 will revise work 

instructions to move two airplane 

effectivities to a different group to 

reflect conversion from passenger 

49208 Federal Register / Vol. 70, No. 162 / Tuesday, August 23, 2005 / Proposed Rules 

configuration to special freighter 

configuration and will add a note that 

no work needs to be done at Door 3 lefthand and right-hand if Boeing Service 

Bulletin 747–25–2666, Revision 2, dated 

April 24, 2003, has previously been 

incorporated.’’

The commenter asks that the term 

‘‘pulley guard bracket’’ be changed to 

‘‘cable guard bracket’’ in that same 

section and in the paragraph following 

‘‘modification’’ of the original NPRM. 

The commenter provides no reason for 

these changes. 

The commenter also asks that Boeing 

Special Attention Service Bulletin 747–

25–3307, Revision 1, dated February 12, 

2004, be added to the second paragraph 

of the ‘‘Explanation of Relevant Service 

Information’’ section of the original 

NPRM. The original issue of the service 

bulletin was referenced in the original 

NPRM as the source of service 

information for modifying the cable 

release sliders. The commenter also asks 

that the following be added to that 

paragraph: ‘‘Note: Revision 1 will add 

airplanes to service bulletin effectivities, 

combine Groups 2 and 3, and revise 

work instructions and Figure 2 to 

provide airlines with an alternate, easier 

modification.’’

The commenter asks that the phrase 

‘‘of the escape slide/raft pack assembly’’

be changed to ‘‘of the floor-mounted 

upper deck slide pack assembly.’’ The 

commenter provides no reason for these 

changes. 

We acknowledge and agree with the 

commenter’s remarks on the preamble 

of the original NPRM as these 

descriptions provide clarification; 

however, the ‘‘Explanation of Relevant 

Service Information’’ section is not 

restated in this supplemental NPRM. 

We have changed the term ‘‘pulley 

guard bracket’’ to ‘‘cable guard bracket’’

in paragraph (a)(2) of the supplemental 

NPRM, which is the only paragraph 

where the term is used. We have also 

changed the phrase ‘‘of the escape slide/

raft pack assembly’’ to ‘‘of the floormounted upper deck slide pack 

assembly’’ in paragraph (b) of the 

supplemental NPRM. 

Since issuance of the original NPRM, 

Boeing has issued, and we have 

reviewed, Boeing Special Attention 

Service Bulletin 747–25–3274, Revision 

2, dated August 26, 2004; and Revision 

3, dated December 16, 2004. Revision 2 

contains the changes described 

previously by the commenter. Revision 

2 also clarifies the airplanes on which 

certain actions must be done. Revision 

3 is essentially the same as Revision 2, 

but the work hours and parts cost for the 

modification are reduced and Revision 

3 provides further clarification of 

certain actions. Revision 3 specifies that 

no more work is necessary on airplanes 

changed as shown in Revision 2, except 

that certain cable assemblies must be 

replaced with new cable assemblies for 

airplanes on which Boeing Service 

Bulletin 747–25–2666, Revision 2, dated 

April 24, 2003; and Goodrich Service 

Bulletin 25–092, Revision 3, dated 

December 8, 1986 (superseded by 

Goodrich Service Bulletin 25–238, 

Revision 1, dated January 31, 2003); 

have been incorporated at Door 3 of the 

emergency exit. Service Bulletin 747–

25–2666 describes procedures for 

installation of a one-piece ramp/slide at 

Door 3 of the emergency exit. Service 

Bulletins 25–092 and 25–238 describe 

procedures for modification of the 

escape slide raft assembly. We have 

added the new requirement specified in 

Service Bulletin 25–238 to paragraph 

(a)(2) of the supplemental NPRM. 

In addition, as specified in Revision 3 

of Service Bulletin 747–25–3274, no 

further action is required if corrective 

actions were performed in accordance 

with previous revisions, except as 

specified in paragraph 1.D., 

‘‘Description’’, of the service bulletin. 

That paragraph, in part, specifies that no 

more work is necessary on airplanes 

changed per Revision 1 of the service 

bulletin, except airplanes RD103 or 

RD104 that have incorporated Service 

Bulletin 747–25–2258 and have stored 

gas upper deck slides that should be 

modified by the instructions for Group 

1 and Group 13 airplanes, as specified 

in Revision 3 of Service Bulletin 747–

25–3274. Therefore, we have added 

Revision 3 of the service bulletin for 

accomplishing the modification 

specified in paragraph (a) of this 

supplemental NPRM, except as 

specified in paragraph 1.D. of the 

service bulletin. 

We have also reviewed Boeing Special 

Attention Service Bulletin 747–25–

3307, Revision 1, dated February 12, 

2004; and Revision 2, dated July 8, 

2004. Revision 1 contains the changes 

described previously. Revision 2 is 

essentially the same as Revision 1, and 

specifies that no more work is necessary 

on airplanes changed as shown in 

Revision 1. We have referenced 

Revision 2 of the service bulletin as the 

appropriate source of service 

information for accomplishing the 

modification required by paragraph (b) 

of this supplemental NPRM.

Request To Change Parts Installation 

Paragraph 

One commenter, the airplane 

manufacturer, asks that paragraph (c) of 

the original NPRM be changed. The 

commenter states that, as written, 

paragraph (c) would not allow 

installation of certain parts on any 

airplane after the effective date of the 

AD. The commenter adds that it finds 

the requirements in this paragraph 

excessively restrictive because those 

requirements would not allow slides to 

be moved from one airplane to another, 

or installation of an overhauled slide 

during the next 36 months if an old part 

number cable is installed. The 

commenter states that, since the original 

NPRM affects slide/raft pack assemblies 

rather than airplanes, installing old 

cables after the effective date of the AD 

should be restricted to include the slide/

raft pack assemblies only. The 

commenter suggests that paragraph (c) 

be changed as follows: ‘‘As of the 

effective date of this AD, no one may 

install, on any slide/raft pack assembly, 

a pin cable assembly with a part number 

listed.’’

In light of the rationale provided by 

the commenter, we agree with the 

remark that the proposed requirements 

of paragraph (c) are too restrictive. 

Operators must comply with the 

requirements of this AD by the 

compliance time specified in paragraph 

(a) of the supplemental NPRM. If an 

operator must install an escape slide, it 

is their responsibility to ensure that all 

affected parts of that slide conform to 

the requirements of this supplemental 

NPRM by the compliance deadline. 

Accordingly, paragraph (c) of the 

proposed rule has not been included in 

this supplemental NPRM. (Operators 

should note, however, that once an 

airplane has been modified according to 

this AD, the airplane cannot be 

modified in any way that negates 

accomplishment of the actions in this 

AD—i.e., an escape slide with a 

modified cable assembly cannot be 

replaced with an escape slide with an 

unmodified cable assembly.) 

Request To Remove Requirement for 

Prior or Concurrent Modification of 

Cable Release Sliders 

The same commenter states that it 

does not agree that modification/

replacement of the cable release sliders 

on the floor-mounted upper deck escape 

slide (as specified in paragraph (b) of 

the original NPRM) warrants an AD. 

Boeing Special Attention Service 

Bulletin 747–25–3307, Revision 2, dated 

July 8, 2004, is referenced as the 

appropriate source of service 

information for the concurrent 

modification required by paragraph (b). 

The commenter notes that although 

deployment forces can be higher than 

normal if the modification/replacement 

is not accomplished, the commenter is 

Federal Register / Vol. 70, No. 162 / Tuesday, August 23, 2005 / Proposed Rules 49209

not aware of any non-deployment due to 

this condition. 

We partially agree with the 

commenter. We agree that certain 

concurrent actions specified in Boeing 

Special Attention Service Bulletin 747–

25–3307, Revision 2, are not necessary. 

We have determined that the concurrent 

modification specified in Figure 1 of the 

service bulletin is not required; 

however, the concurrent modification of 

the outboard cover panel, as specified in 

Figure 2 of the service bulletin, must be 

accomplished on Groups 2, 5, 6, 7, 8, 11, 

12, 13, 14, and 15 airplanes. We have 

changed paragraph (b) of this 

supplemental NPRM accordingly. 

Request To Change Applicability 

One commenter asks that the 

applicability specified in the original 

NPRM be changed to specify a 

component (appliance), rather than 

airplanes, and suggests that the AD 

apply only to airplanes with floormounted upper deck slide pack 

assemblies having the part numbers 

identified in the referenced service 

information. The commenter states that 

the applicability specified can be 

misleading and has the potential to 

cause compliance and record-keeping 

errors. The commenter adds that the 

original NPRM should not be applicable 

to airplanes because the actions are 

required for a removable component; 

the component can be removed, 

repaired, and/or overhauled separately 

from the airplane, moved to another 

airplane, or stored until installation. 

The commenter notes that it operates 

several Model 747–100 series airplanes 

that do not have the affected floormounted upper deck slide pack 

assemblies installed, although the 

airplanes are included in the 

applicability. In addition, the 

commenter states that it operates one 

Model 747SR series airplane that is 

equipped with an affected assembly, but 

is not included in the effectivity 

specified in the referenced service 

information. 

We do not agree with the commenter. 

Our general policy, when an unsafe 

condition results from an appliance or 

other item that is, or could be, installed 

on multiple airplane models, is that the 

AD is issued so that it is applicable to 

all of those airplane models, rather than 

to the item. The applicability of the 

original NPRM states ‘‘all’’ and takes 

precedence over the service bulletin 

effectivity. By making the AD applicable 

to the airplane models on which the 

appliance or other item is installed, we 

ensure that operators of those airplanes 

will be notified directly of the unsafe 

condition and the action required to 

correct it. While we assume that an 

operator will know the models of 

airplanes that it operates, there is a 

potential that the operator will not 

know or be aware of specific items that 

are installed on its airplanes. Therefore, 

calling out the airplane model as the 

subject of the AD prevents ‘‘unknowing 

non-compliance’’ on the part of the 

operator. 

Additionally, there have been reports 

of non-deployments of escape slides 

that were delivered by Boeing with the 

airplane, as well as those that were 

installed post-delivery by the 

supplemental type certification (STC) 

process. After reviewing the in-service 

incidents, we found that all of the 

escape slides installed per the STC used 

the packboards that were delivered with 

the airplane. We then determined that 

specifying the airplane model in the 

applicability of the NPRM instead of the 

escape slide itself ensures that all 

discrepant cable assemblies are replaced 

on all Model 747 escape slide 

packboards, regardless of which 

airplane the escape slide is installed on. 

Therefore, components on airplanes not 

affected would not be overlooked. We 

have made no change to the 

supplemental NPRM in this regard. 

Another commenter states that in the 

applicability of the original NPRM, 

Model 747–400F series airplanes are 

missing. The commenter notes that the 

upper deck slides on Model 747–400F 

series airplanes are the same as the 

slides installed on Model 747–200 series 

airplanes. 

Although no specific request was 

made, we infer that the commenter 

wants us to add Model 747–400F series 

airplanes to the applicability of the 

supplemental NPRM. Although the 

slides for Model 747–200 and 747–400F 

series airplanes are similar, they are not 

interchangeable. When the Model 747–

400F series airplanes were built, the 

escape slides that were installed had 

newer cover release cables which 

changed the configuration; therefore, the 

actions specified in the supplemental 

NPRM are not required for Model 747–

400F series airplanes. We have made no 

change to the supplemental NPRM in 

this regard. 

FAA’s Determination and Proposed 

Requirements of the Supplemental 

NPRM 

Since a certain change, discussed 

above, expands the scope of the original 

NPRM, we have determined that it is 

necessary to reopen the comment period 

to provide additional opportunity for 

public comment on this supplemental 

NPRM. 

Changes to 14 CFR Part 39/Effect on the 

Original NPRM 

On July 10, 2002, the FAA issued a 

new version of 14 CFR part 39 (67 FR 

47997, July 22, 2002), which governs the 

FAA’s airworthiness directives system. 

The regulation now includes material 

that relates to altered products, special 

flight permits, and alternative methods 

of compliance (AMOCs). These changes 

are reflected in this supplemental 

NPRM.

Cost Impact 

There are approximately 592 

airplanes of the affected design in the 

worldwide fleet. We estimate that 187 

airplanes of U.S. registry would be 

affected by this proposed AD. 

It would take approximately 2 work 

hours per escape slide to accomplish the 

new proposed modification of the 

escape slide/raft pack assembly, at an 

average labor rate of $65 per work hour. 

Required parts would cost between 

$8,354 and $30,688 per airplane. Based 

on these figures, the cost impact of the 

modification of the escape slide/raft 

pack assembly proposed by this AD on 

U.S. operators is estimated to be 

between $1,586,508 and $5,762,966, or 

between $8,484 and $30,818 per 

airplane. 

Should an operator be required to 

accomplish the overhaul of the cable 

release sliders, it would take 

approximately 2 work hours to 

accomplish the proposed overhaul, at an 

average labor rate of $65 per work hour. 

Required parts cost would be negligible. 

Based on these figures, the cost impact 

of the overhaul of the cable release 

sliders proposed by this AD on U.S. 

operators is estimated to be $130 per 

escape slide and $260 per airplane. 

Should an operator be required to 

accomplish the replacement of the cable 

release sliders, it would take 

approximately 1 work hour to 

accomplish the proposed replacement, 

at an average labor rate of $65 per work 

hour. Required parts would cost 

approximately $2,940 per escape slide. 

Based on these figures, the cost impact 

of the replacement of the cable release 

sliders proposed by this AD on U.S. 

operators is estimated to be $3,005 per 

escape slide or $6,010 per airplane. 

The cost impact figures discussed 

above are based on assumptions that no 

operator has yet accomplished any of 

the proposed requirements of this AD 

action, and that no operator would 

accomplish those actions in the future if 

this AD were not adopted. The cost 

impact figures discussed in AD 

rulemaking actions represent only the 

time necessary to perform the specific 

49210 Federal Register / Vol. 70, No. 162 / Tuesday, August 23, 2005 / Proposed Rules 

actions actually required by the AD. 

These figures typically do not include 

incidental costs, such as the time 

required to gain access and close up, 

planning time, or time necessitated by 

other administrative 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 

products identified in this rulemaking 

action. 

Regulatory Impact 

The regulations proposed herein 

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. Therefore, 

it is determined that this proposal 

would not have federalism implications 

under Executive Order 13132. 

For the reasons discussed above, I 

certify that 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) if 

promulgated, 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. A copy of the draft 

regulatory evaluation prepared for this 

action is contained in the Rules Docket. 

A copy of it may be obtained by 

contacting the Rules Docket at the 

location provided under the caption 

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation 

safety, Safety.

The Proposed Amendment 

Accordingly, pursuant to the 

authority delegated to me by the 

Administrator, the Federal Aviation 

Administration proposes to amend part 

39 of the Federal Aviation Regulations 

(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. Section 39.13 is amended by 

adding the following new airworthiness 

directive:

Boeing: Docket 2001–NM–213–AD.

Applicability: All Model 747SP, 747SR, 

747–100, –100B, –100B SUD, –200B, –200C, 

–200F, and –300 series airplanes; certificated 

in any category. 

Compliance: Required as indicated, unless 

accomplished previously. 

To prevent improper deployment of the 

escape slide/raft or blockage of the 

passenger/crew doors in the event of an 

emergency evacuation, which could result in 

injury to passengers or crewmembers, 

accomplish the following:

Modification 

(a) Within 36 months after the effective 

date of this AD: Accomplish the actions 

specified in paragraphs (a)(1) and (a)(2) of 

this AD, as applicable, in accordance with 

Boeing Special Attention Service Bulletin 

747–25–3274, Revision 3, dated December 

16, 2004. Previously accomplishing the 

modification in accordance with Boeing 

Special Attention Service Bulletin 747–25–

3274, Revision 1, dated January 9, 2003; or 

Revision 2, dated August 26, 2004; is 

acceptable for compliance with paragraph 

(a)(1) of this AD, except as specified in 

paragraph 1.D, ‘Description’, of Revision 3 of 

the service bulletin. 

(1) For airplanes on which the actions 

specified in Boeing Service Bulletin 747–25–

2666, Revision 2, dated April 24, 2003; and 

Goodrich Service Bulletin 25–238, Revision 

1, dated January 31, 2003, have been 

accomplished: Replace cable assemblies 

having part number (P/N) 69B55462–( ) with 

new cable assemblies having P/N 416U6004–

1. 

(2) For airplanes on which the 

modification required by paragraph (a)(1) of 

this AD has not been accomplished: Modify 

the escape slide/raft pack assembly (includes 

removing the slide packs, replacing the cover 

release pin cable assemblies with new 

assemblies, and removing the cable guard 

bracket, as applicable). 

Concurrent Modification 

(b) For Groups 2, 5, 6, 7, 8, 11, 12, 13, 14, 

and 15 airplanes: Prior to or concurrently 

with accomplishment of paragraph (a) of this 

AD, modify the outboard cover panel of the 

cable release sliders of the floor-mounted 

upper deck slide pack assembly, as specified 

in Figure 2 of Boeing Special Attention 

Service Bulletin 747–25–3307, Revision 2, 

dated July 8, 2004. 

Alternative Methods of Compliance 

(c) The Manager, Seattle Aircraft 

Certification Office (ACO), FAA, has the 

authority to approve AMOCs for this AD, if 

requested in accordance with the procedures 

found in 14 CFR 39.19.

Issued in Renton, Washington, on August 

12, 2005. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service.

[FR Doc. 05–16751 Filed 8–22–05; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39

[Docket No. FAA–2005–22169; Directorate 

Identifier 2005–NM–094–AD] 

RIN 2120–AA64

Airworthiness Directives; Learjet 

Model 23, 24, 24A, 24B, 24B–A, 24C, 

24D, 24D–A, 24E, 24F, 24F–A, 25, 25A, 

25B, 25C, 25D, and 25F Airplanes

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT).

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain Learjet Model 23, 24, 24A, 24B, 

24B–A, 24C, 24D, 24D–A, 24E, 24F, 

24F–A, 25, 25A, 25B, 25C, 25D, and 25F 

airplanes. This proposed AD would 

require replacement of the spherical 

accumulator for the main hydraulic 

system with a new cylindrical 

accumulator. For certain airplanes, this 

proposed AD would also require 

modification of the accumulator 

pressure gauge. This proposed AD is 

prompted by reports of the failure of 

two thrust reverser accumulators (which 

are similar to the main hydraulic 

system’s spherical accumulator) and 

fatigue cracks found on four thrust 

reverser accumulators. We are 

proposing this AD to prevent failure of 

the spherical accumulator for the main 

hydraulic system, due to fatigue 

cracking on the threads, which could 

result in the loss of hydraulic power, 

damage to the surrounding airplane 

structure, and loss of airplane control. 

The failure of the accumulator could 

also result in injury to any persons in 

the surrounding area. The loss of 

hydraulic fluid could also leak onto a 

potential source of ignition and result in 

a consequent fire.

DATES: We must receive comments on 

this proposed AD by October 7, 2005.