
[Federal Register: April 21, 2008 (Volume 73, Number 77)]
[Rules and Regulations]               
[Page 21227-21229]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21ap08-5]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29116; Directorate Identifier 2007-NM-064-AD; 
Amendment 39-15476; AD 2008-08-22]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. 
This AD requires a one-time inspection to determine the material of the 
forward and aft gray water drain masts. For airplanes having composite 
gray water drain masts, this AD requires installation of a bonding 
jumper between a ground and the clamp on the tube of the forward and 
aft gray water composite drain masts. This AD results from a report of 
charred insulation blankets and burned wires around the forward gray 
water composite drain mast found during an inspection of the forward 
cargo compartment on a Model 767-300F airplane. We are issuing this AD 
to prevent a fire near a composite drain mast and possible disruption 
of the electrical power system caused by a lightning strike on a 
composite drain mast, which could result in the loss of several 
functions essential for safe flight.

DATES: This AD is effective May 27, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 27, 
2008.

ADDRESSES: 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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Nicholas Wilson, 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) 917-6476; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) (the ``original 
NPRM'') to amend 14 CFR part 39 to include an airworthiness directive 
(AD) that would apply to all Boeing Model 737-600, -700, -700C, -800, 
and -900 series airplanes. That NPRM was published in the Federal 
Register on September 6, 2007 (72 FR 51201). That NPRM proposed to 
require a one-time inspection to determine the material of the forward 
and aft gray water drain masts. For airplanes having composite gray 
water drain masts, that NPRM also proposed to require installation of a 
bonding jumper between a ground and the clamp on the tube of the 
forward and aft gray water composite drain masts.

Actions Since NPRM Was Issued

    Since we issued the NPRM, Boeing has issued new service information 
that includes corrected measurement values and procedures that should 
be followed if the resistance of the bonding jumper exceeds certain 
values during the initial resistance check.
    We have reviewed Boeing Special Attention Service Bulletin 737-30-
1056, Revision 1, dated October 25, 2007. The service bulletin 
describes procedures for installing a bonding jumper between a ground 
and the clamp on the tube of the forward and aft gray water composite 
drain mast. We have revised this final rule to refer to Revision 1 of 
the service bulletin as the appropriate source of service information 
for the required actions. We have also added paragraph (h) to this 
final rule to give credit for actions done previously in accordance 
with Boeing Special Attention Service Bulletin 737-30-1056, dated 
February 28, 2007, provided the results of the resistance measurement 
meet the values specified in Revision 1; we have re-identified 
subsequent paragraphs accordingly.

Comments

    We have considered the following comments on the NPRM.

Request To Clarify the Proposed Applicability

    Boeing requests that we revise the Applicability statement of the 
NPRM to clarify the affected airplanes. Boeing states that airplanes 
having line numbers 1935 and subsequent have the bonding jumper 
installed during production and should not be subject to the NPRM. 
Boeing asserts that the NPRM should only be applicable to airplanes 
delivered with composite drain masts without the bonding jumper or 
airplanes with spare interchangeability notes allowing replacement of 
the aluminum drain masts with composite drain masts.
    We partially agree. For the reason stated by Boeing, we have 
determined that these airplanes should not be subject to this AD. 
However, we do not agree to revise the Applicability statement of this 
AD as suggested by

[[Page 21228]]

Boeing. Instead, we have revised the Applicability statement of this 
final rule to state, ``Boeing Model 737-600, -700, -700C, -800, and -
900 series airplanes, certificated in any category; as identified in 
Boeing Special Attention Service Bulletin 737-30-1056, Revision 1, 
dated October 25, 2007.'' We have confirmed that the effectivity of 
this service bulletin matches the applicability suggested by Boeing.

Request To Revise the Proposed Costs of Compliance

    Air Transport Association (ATA), on behalf of its member American 
Airlines (AAL), states that the work-hour estimate of 9.75 hours per 
airplane provided in the service bulletin is more realistic than the 4-
hour estimate provided in the NPRM.
    From this comment, we infer that AAL is requesting that we revise 
the Costs of Compliance section of the NPRM to reflect 9.75 work-hours 
per airplane to do the proposed actions. We do not agree. The cost 
information below describes only the direct costs of the specific 
actions required by this AD. Based on the best data available, the 
manufacturer provided the number of work hours (4) necessary to do the 
required actions. This number represents the time necessary to perform 
only the actions actually required by this AD. We recognize that, in 
doing the actions required by an AD, operators might incur incidental 
costs in addition to the direct costs. The cost analysis in AD 
rulemaking actions, however, typically does not include incidental 
costs such as the time required to gain access and close up, time 
necessary for planning, or time necessitated by other administrative 
actions. Those incidental costs, which might vary significantly among 
operators, are almost impossible to calculate. We have made no change 
to this final rule in this regard.

Request To Include Parts Installation Requirement

    ATA, on behalf of its member Delta Airlines (Delta), suggests that 
the AD specify that a composite drain mast cannot replace an aluminum 
drain mast unless the bonding jumper is installed according to Boeing 
Special Attention Service Bulletin 737-30-1056, Revision 1, dated 
October 25, 2007. Delta asserts that, according to the airplane 
illustrated parts catalog, the composite and aluminum drain masts are 
interchangeable, which could lead to unintentional non-compliance with 
the AD.
    We agree that the composite and aluminum drain mast can be 
interchangeable. Therefore, for the reasons given by Delta, we have 
added a new paragraph (i), ``Parts Installation,'' to this final rule 
to prohibit installation of a composite gray water drain mast, unless a 
bonding jumper is also installed, as specified in paragraph (g) of this 
final rule.

Additional Changes to This Final Rule

    We have also updated the Costs of Compliance section of this final 
rule to reflect the current number of U.S.-registered airplanes, and 
the cost of parts necessary to accomplish the required actions.

Costs of Compliance

    There are about 1,906 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Average                                                Number of U.S.-
              Action                    Work hours        labor rate         Parts          Cost per airplane        registered           Fleet cost
                                                           per hour                                                  airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection to determine gray       1...................          $80  None...............  $80................  873................  $69,840.
 water drain mast material.
Installation of bonding jumper...  Between 2 and 4                80  Between $8 and $16,  Between $168 and     Up to 873..........  Between $146,664
                                    (depending on                      depending on kit.    $336.                                     and $293,328.
                                    airplane
                                    configuration).
--------------------------------------------------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

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

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979), 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:


[[Page 21229]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-08-22 Boeing: Amendment 39-15476. Docket No. FAA-2007-29116; 
Directorate Identifier 2007-NM-064-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective May 27, 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 Special Attention Service Bulletin 737-30-1056, 
Revision 1, dated October 25, 2007.

Unsafe Condition

    (d) This AD results from a report of charred insulation blankets 
and burned wires around the forward gray water composite drain mast 
found during an inspection of the forward cargo compartment on a 
Model 767-300F airplane. We are issuing this AD to prevent a fire 
near a composite drain mast and possible disruption of the 
electrical power system caused by a lightning strike on a composite 
drain mast, which could result in the loss of several functions 
essential for safe flight.

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.

Inspection To Determine Material of Gray Water Drain Masts

    (f) Within 60 months after the effective date of this AD, 
inspect the forward and aft gray water drain masts to determine 
whether the drain masts are made of aluminum or composite. A review 
of airplane maintenance records is acceptable in lieu of this 
inspection if the material of the forward and aft gray water drain 
masts can be conclusively determined from that review.
    (1) For any aluminum gray water drain mast identified during the 
inspection or records check required by paragraph (f) of this AD, no 
further action is required by this paragraph for that drain mast 
only.
    (2) For any composite gray water drain mast identified during 
the inspection or records check required by paragraph (f) of this 
AD, do the actions specified in paragraph (g) of this AD.

Installation of Bonding Jumper

    (g) For any composite gray water drain mast identified during 
the inspection or records check required by paragraph (f) of this 
AD: Within 60 months after the effective date of this AD, install a 
bonding jumper between a ground and the clamp on the tube of the 
gray water composite drain mast, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-30-1056, Revision 1, dated October 25, 2007.

Actions Done Previously Using Previous Service Information

    (h) Actions done before the effective date of this AD according 
to Boeing Special Attention Service Bulletin 737-30-1056, dated 
February 28, 2007, are considered acceptable for compliance with the 
corresponding actions specified in this AD provided the results of 
the resistance measurements meet the acceptable values specified in 
Boeing Special Attention Service Bulletin 737-30-1056, Revision 1, 
dated October 25, 2007.

Parts Installation

    (i) As of the effective date of this AD, no person may install, 
on any airplane, a composite gray water drain mast, unless a bonding 
jumper is also installed, as specified in paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with 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.

Material Incorporated by Reference

    (k) You must use Boeing Special Attention Service Bulletin 737-
30-1056, Revision 1, dated October 25, 2007, to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on April 7, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-8254 Filed 4-18-08; 8:45 am]

BILLING CODE 4910-13-P
