Document ID: FAA-2008-0176-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 and -900 Series Airplanes
Posted Date: 2008-02-15T05:00Z

[Federal Register: February 15, 2008 (Volume 73, Number 32)]
[Proposed Rules]               
[Page 8833-8836]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15fe08-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0176; Directorate Identifier 2007-NM-228-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 
and -900 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Boeing Model 737-600, -700, -700C, -800 and -900 series 
airplanes. This proposed AD would require an inspection of the escape 
slides for the forward and aft entry and service doors to determine the 
part number and service bulletin number stenciled on the escape slide 
girt, and modification of the escape slide assemblies. This proposed AD 
also would require concurrent modification of the escape slide latch 
assembly; concurrent inspection of the escape slides to determine the 
part number and service bulletin number stenciled on the escape slide 
girts, and replacement of the trigger housing on the regulator valve 
with improved trigger housing if necessary; and concurrent replacement 
of the rod in the pilot valve regulator with a new improved rod; as 
applicable. This proposed AD results from reports that certain escape 
slides did not automatically inflate when deployed or after the manual 
inflation cable was pulled. We are proposing this AD to prevent failure 
of an escape slide to inflate when deployed, which could result in the 
slide being unusable during an emergency evacuation and consequent 
injury to passengers or crewmembers.

DATES: We must receive comments on this proposed AD by March 31, 2008.

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 AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

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: Robert K. Hettman, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; telephone (425) 917-6457, 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-2008-0176; 
Directorate Identifier 2007-NM-228-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 indicating that Goodrich 5A3307 series 
escape slides did not automatically inflate when deployed on Boeing 
Model 737-600, -700, -700C, -800 and -900 series airplanes. On some of 
these airplanes, the escape slides did not inflate even after the 
manual inflation cable was pulled and the firing cable was pulled out 
of the valve regulator assembly. Investigation revealed that these 
escape slides did not inflate because the piston rod was incorrectly 
installed in the valve regulator assembly of the escape slide. The same 
valve regulator is also used on Goodrich 5A3086 and 5A3088 series 
escape slides. If the rod is installed upside down, the valve regulator 
assembly can be charged but the rod will prevent the regulator from 
activating when the firing cable is pulled. On other airplanes, the 
escape slides did not automatically inflate when deployed, but did 
inflate after the manual inflation cable was pulled. Investigation 
revealed that these escape slides did not automatically inflate because 
there was insufficient force to pull the inflation cable from the 
valve, due to the trigger housing cover deflecting the inflation cable. 
The failure of an escape slide to inflate when deployed, if not 
corrected, could result in the slide being unusable during an emergency 
evacuation and consequent injury to passengers or crewmembers.

Other Related Rulemaking

    On July 13, 2001, we issued AD 2001-15-01, amendment 39-12335 (66 
FR 38361, July 24, 2001), applicable to certain Boeing Model 727 and 
737 airplanes; and Model 757-200, 757-200CB, and 757-300 series 
airplanes. That AD requires modification of the latch assembly of the 
escape slides. For Model 737-600, -700, and -800 series airplanes, that 
AD also requires installation of a cover assembly on the trigger 
housing of the inflation cylinder on the escape slides. For certain

[[Page 8834]]

airplanes, this proposed AD specifies prior or concurrent 
accomplishment of certain requirements of paragraph (a) of AD 2001-15-
01.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 737-25-1491, dated April 
23, 2007. The service bulletin describes procedures for inspecting the 
escape slides to determine the Goodrich part number and service 
bulletin number stenciled on the escape slide girts, and for modifying 
the escape slide assemblies.
    Boeing Service Bulletin 737-25-1491 refers to Goodrich Service 
Bulletin 25-338, Revision 1, dated March 31, 2004, as an additional 
source of service information for modifying the escape slide 
assemblies. The modification includes replacing the regulator piston 
plug in the vespel piston with a new piston plug, installing a new 
ensolite pad on the valise, and replacing the trigger housing cover 
with an improved trigger housing cover.

Concurrent Service Information

    Boeing Service Bulletin 737-25-1491 also specifies prior or 
concurrent accomplishment of the following service bulletins:
     Boeing Service Bulletin 737-25-1404, dated May 25, 2000, 
or Revision 1, dated April 18, 2002, for certain Model 737-600, -700, 
and -800 series airplanes, equipped with any escape slide having P/N 
5A3307-1, P/N 5A3307-3, P/N 5A3086-3, or P/N 5A3088-3. The original 
issue of the service bulletin is required by paragraph (a) of AD 2001-
15-01. This service bulletin describes procedures for modifying the 
escape slide latch assembly.
     Boeing Special Attention Service Bulletin 737-25-1475, 
dated November 26, 2002, for Model 737-600, -700, -700C, -800 and -900 
series airplanes equipped with any escape slide having P/N 5A3086-3 or 
P/N 5A3088-3. Boeing Special Attention Service Bulletin 737-25-1475 
describes procedures for inspecting the four escape slides to determine 
the part number and service bulletin number stenciled on the escape 
slide girts, and replacing the trigger housing on the regulator valve 
with improved trigger housing if Goodrich Service Bulletin 5A3086/
5A3088-25-302 is not stenciled on the girt. For certain airplanes, the 
Boeing service bulletin also specifies that a records review may be 
done in lieu of the inspection to determine the part number. Boeing 
Service Bulletin 737-25-1475 refers to Goodrich Service Bulletin 
5A3086/5A3088-25-336, dated June 17, 2002, as an additional source of 
service information for replacing the trigger housing on the regulator 
valve with new improved trigger housing.
     Goodrich Service Bulletin 25-308, dated January 21, 2000, 
for any escape slide having P/N 5A3307-1, P/N 5A3086-3, or P/N 5A3088-
3; or P/N 5A3307-3 and Goodrich Service Bulletin 5A3307-25-309 
stenciled on the girt. Goodrich Service Bulletin 25-308 describes 
procedures for replacing the rod in the pilot valve regulator with a 
new improved rod.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the(se) same type 
design(s). This proposed AD would require accomplishing the actions 
specified in the service information described previously.

Clarification of Concurrent Service Information

    Although Boeing Service Bulletin 737-25-1491 identifies Boeing 
Special Attention Service Bulletin 737-25-1403, dated May 4, 2000, or 
Revision 1, dated November 29, 2001; and Goodrich Service Bulletin 
5A3307-25-309, dated October 29, 1999; as concurrent requirements, this 
proposed AD would not require accomplishment of those service 
bulletins. (Boeing Service Bulletin 737-25-1491 incorrectly dates the 
original issue of Boeing Special Attention Service Bulletin 737-25-1403 
as November 29, 2001.) Instead, this proposed AD would require 
installing an improved trigger housing cover in accordance with 
Goodrich Service Bulletin 25-338. Goodrich Service Bulletin 25-338 
incorporates a larger escape slide valise pad that provides the same 
shielding function as the trigger housing modification specified in 
Boeing Special Attention Service Bulletin 737-25-1403 and Goodrich 
Service Bulletin 5A3307-25-309. However, some operators might have 
previously incorporated Boeing Special Attention Service Bulletin 737-
25-1403 and Goodrich Service Bulletin 5A3307-25-309 on certain Model 
737-600, -700, and -800 series airplanes delivered with an escape slide 
having P/N 5A3307-1, as required by AD 2001-15-01. For these airplanes, 
this proposed AD would further require replacing the rod in the pilot 
valve regulator with a new improved rod in accordance with Goodrich 
Service Bulletin 25-308.
    Although Boeing Service Bulletin 737-25-1491 identifies Goodrich 
Service Bulletin 5A3086/5A3088-25-302, dated November 13, 1998, or 
Revision 1, dated February 19, 2001, as a concurrent requirement, this 
proposed AD would not require accomplishment of that service bulletin. 
However, some operators might have previously accomplished the actions 
specified in Goodrich Service Bulletin 5A3086/5A3088-25-302. If 
Goodrich Service Bulletin 5A3086/5A3088-25-302 has been previously 
accomplished on Model 737-600, -700, -700C, -800 and -900 series 
airplanes equipped with any escape slide having P/N 5A3086-3 or P/N 
5A3088-3, the trigger housing replacement specified in Boeing Special 
Attention Service Bulletin 737-25-1475 and Goodrich Service Bulletin 
5A3086/5A3088-25-336 would not need to be accomplished.

Costs of Compliance

    We estimate that this proposed AD would affect 480 airplanes of 
U.S. registry. We also estimate that it would take about 1 work-hour 
per product to comply with the proposed inspection. The average labor 
rate is $80 per work-hour. Based on these figures, we estimate the cost 
of this proposed AD to the U.S. operators to be $38,400 or $80 per 
product.
    The following table provides the estimated costs, at an average 
labor rate of $80 per work-hour, for U.S. operators to comply with the 
proposed concurrent actions, if applicable.

                             Estimated Costs
------------------------------------------------------------------------
                                                               Cost per
              Action                Work hours     Parts       airplane
------------------------------------------------------------------------
Concurrent actions specified in              2       $1,424       $1,584
 Boeing Service Bulletin 737-25-
 1404............................
Concurrent actions specified in              3        1,740        1,980
 Boeing Special Attention Service
 Bulletin 737-25-1475............

[[Page 8835]]

Concurrent actions specified in              3          516          756
 Goodrich Service Bulletin 25-308
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866,
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979), and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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.

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new AD:

Boeing: Docket No. FAA-2008-0176; Directorate Identifier 2007-NM-
228-AD.

Comments Due Date

    (a) We must receive comments by March 31, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800 
and -900 series airplanes, certificated in any category, as 
identified in Boeing Service Bulletin 737-25-1491, dated April 23, 
2007.

Unsafe Condition

    (d) This AD results from reports that certain escape slides did 
not inflate when deployed or after the manual inflation cable was 
pulled. We are issuing this AD to prevent failure of an escape slide 
to inflate when deployed, which could result in the slide being 
unusable during an emergency evacuation and consequent injury to 
passengers or crewmembers.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Inspection and Modification

    (f) Within 36 months after the effective date of this AD, 
inspect the escape slides for the forward and aft entry and service 
doors to determine the Goodrich part number and service bulletin 
number stenciled on the escape slide girts, and modify the escape 
slide assemblies, in accordance with the Accomplishment Instructions 
of Boeing Service Bulletin 737-25-1491, dated April 23, 2007.

    Note 1: Boeing Service Bulletin 737-25-1491 refers to Goodrich 
Service Bulletin 25-338, Revision 1, dated March 31, 2004, as an 
additional source of service information for modifying the escape 
slide assemblies.

Concurrent Requirements

    (g) Prior to or concurrently with accomplishing the actions 
required by paragraph (f) of this AD, do the applicable actions 
specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD.
    (1) For Model 737-600, -700, and -800 series airplanes 
identified in Boeing Service Bulletin 737-25-1404, dated May 25, 
2000, equipped with any escape slide having P/N 5A3307-1, P/N 
5A3307-3, P/N 5A3086-3, or P/N 5A3088-3: Modify the escape slide 
latch assembly in accordance with Boeing Service Bulletin 737-25-
1404, dated May 25, 2000, as required by paragraph (a) of AD 2001-
15-01; or Boeing Service Bulletin 737-25-1404, Revision 1, dated 
April 18, 2002.
    (2) For Model 737-600, -700, -700C, -800 and -900 series 
airplanes equipped with any escape slide having P/N 5A3086-3 or P/N 
5A3088-3: Inspect the four escape slides to determine the part 
number and service bulletin number stenciled on the escape slide 
girts, and replace the trigger housing on the regulator valve with 
improved trigger housing if Goodrich Service Bulletin 5A3086/5A3088-
25-302 is not stenciled on the girt, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-25-1475, dated November 26, 2002. For airplanes 
identified as Group 2 in the service bulletin, a records review may 
be done in lieu of the inspection to determine the part number.

    Note 2: Boeing Service Bulletin 737-25-1475 refers to Goodrich 
Service Bulletin 5A3086/5A3088-25-336, dated June 17, 2002, as an 
additional source of service information for replacing the trigger 
housing on the regulator valve with new improved trigger housing.

    (3) For Model 737-600, -700, -700C, -800 and -900 series 
airplanes equipped with any escape slide having P/N 5A3307-1, P/N 
5A3086-3, or P/N 5A3088-3; or P/N 5A3307-3 and Goodrich Service 
Bulletin 5A3307-25-309 stenciled on the girt: Replace the rod in the 
pilot valve regulator with a new improved rod in accordance with 
Goodrich Service Bulletin 25-308, dated January 21, 2000.

Terminating Action for AD 2001-15-01

    (h) For Model 737-600, -700, and -800 series airplanes 
identified in Boeing Special Attention Service Bulletin 737-25-1403, 
dated May 4, 2000: Accomplishing the replacement of the regulator 
piston plug in the vespel piston with a new piston plug, 
installation of a new insolate pad on the valise, and removal of the 
trigger housing cover, in accordance with Goodrich Service Bulletin 
25-338, Revision 1, dated March 31, 2004, terminates the 
modification specified in Boeing Special Attention Service Bulletin 
737-25-1403, dated May 4, 2000, as required by paragraph (a) of AD 
2001-15-01. All other applicable actions required by paragraph (a) 
of AD 2001-15-01 must be fully complied with.
    (i) For Model 737-600, -700, and -800 series airplanes: 
Installation of a cover

[[Page 8836]]

assembly on the trigger housing of the inflation cylinder on the 
escape slides in accordance with Boeing Special Attention Service 
Bulletin 737-25-1403, Revision 1, dated November 29, 2001, 
terminates the corresponding action required by paragraph (a) of AD 
2001-15-01. All other applicable actions required by paragraph (a) 
of AD 2001-15-01 must be fully complied with.
    (j) For Model 737-600, -700, and -800 series airplanes: 
Modification of the escape slide latch assembly in accordance with 
Boeing Service Bulletin 737-25-1404, Revision 1, dated April 18, 
2002, terminates the corresponding action required by paragraph (a) 
of AD 2001-15-01. All other applicable actions required by paragraph 
(a) of AD 2001-15-01 must be fully complied with.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
ATTN: Robert K. Hettman, Aerospace Engineer, Cabin Safety and 
Environmental Systems Branch, ANM-150S, 1601 Lind Avenue SW., 
Renton, Washington 98057-3356; telephone (425) 917-6457, fax (425) 
917-6590; has the authority to approve AMOCs for this AD, if 
requested using the procedures found in 14 CFR 39.19.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on February 10, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E8-2887 Filed 2-14-08; 8:45 am]

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