
[Federal Register Volume 77, Number 122 (Monday, June 25, 2012)]
[Proposed Rules]
[Pages 37831-37834]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-15469]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0617; Directorate Identifier 2007-NM-354-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: We are revising an earlier proposed airworthiness directive 
(AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, -
900, and -900ER series airplanes. That NPRM proposed to require 
repetitive operational tests of the engine fuel suction feed of the 
fuel system, and other related testing if necessary. That NPRM was 
prompted by a report of an in-service occurrence of total loss of boost 
pump pressure of the fuel feed system, followed by loss of fuel system 
suction feed capability on one engine, and in-flight shutdown of the 
engine. This action revises that NPRM by proposing to require 
repetitive operational tests, and other related testing and corrective 
action if necessary. We are proposing this supplemental NPRM to detect 
and correct loss of the engine fuel suction feed capability of the fuel 
system, which in the event of total loss of the fuel boost pumps could 
result in dual engine flameout, inability to restart the engines, and 
consequent forced landing of the airplane.
    Since these actions impose an additional burden over that proposed 
in the previous NPRM, we are reopening the comment period to allow the 
public the chance to comment on these proposed changes.

DATES: We must receive comments on this supplemental NPRM by August 9, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The

[[Page 37832]]

street address for the Docket Office (phone: 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Sue Lucier, Aerospace Engineer, 
Propulsion Branch, ANM-140S, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: 425-917-6438; fax: 425-917-6590; email: 
suzanne.lucier@faa.gov.

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-2008-0617; 
Directorate Identifier 2007-NM-354-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 issued an NPRM to amend 14 CFR part 39 to include an AD that 
would apply to certain The Boeing Company Model 737-600, -700, -700C, -
800, -900, and -900ER series airplanes. That NPRM published in the 
Federal Register on June 6, 2008 (73 FR 32255). That NPRM proposed to 
require repetitive operational tests of the engine fuel suction feed of 
the fuel system, and other related testing if necessary.

Actions Since Previous NPRM (73 FR 32255, June 6, 2008) Was Issued

    Since we issued the previous NPRM (73 FR 32255, June 6, 2008), we 
have received comments from operators indicating a high level of 
difficulty performing the actions in the previous NPRM during 
maintenance operations.

Relevant Service Information

    We reviewed Section 9, Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs), D626A001-CMR, Revision 
August 2011, of the Boeing 737-600/700/700C/800/900/900ER Maintenance 
Planning Data (MPD) Document. Among other things, Section 9 describes 
AWL No. 28-AWL-101, Engine Fuel Suction Feed Operational Test, of 
Section E., AWLS--Fuel Systems, which provides procedures for 
performing repetitive operational tests of the engine fuel suction feed 
of the fuel system.

Comments

    We gave the public the opportunity to comment on the previous NPRM 
(73 FR 32255, June 6, 2008). The following presents the comments 
received on the previous NPRM and the FAA's response to each comment.

Requests To Change Approved Method of Compliance for Operational Test

    Continental Airlines (CAL), Airlines for America (A4A) on behalf of 
its member American Airlines (AAL), and Sun Country Airlines asked that 
the approved method of compliance specified in paragraph (f) of the 
previous NPRM (73 FR 32255, June 6, 2008) be changed to refer to the 
airplane maintenance manual (AMM) instead of requiring the repetitive 
tasks.
    CAL and AAL recommended that certain language in paragraph (f) of 
the previous NPRM (73 FR 32255, June 6, 2008) be changed to require 
incorporation of the operational test into the operator's maintenance 
program in the same manner as the Instructions for Continued 
Airworthiness (ICA).
    AAL stated that since there is no modification or terminating 
action for the actions specified in the previous NPRM (73 FR 32255, 
June 6, 2008), the AD need not mandate the task itself. AAL noted that 
operators should be required to incorporate into their respective 
maintenance programs a mandatory task, as specified in CMRs, AWLs, or 
airworthiness limitation items. AAL stated that this approach would be 
consistent with the processes utilized by operators for the SFAR 88 (66 
FR 23086, May 7, 2001) requirements.
    We agree with the requests to refer to the AMM. AWL No. 28-AWL-101 
refers to the AMM. We have replaced paragraph (f) of the previous NPRM 
(73 FR 32255, June 6, 2008), with a new paragraph (g) in this 
supplemental NPRM that would require the operational tests as specified 
in the MPD.
    Sun Country Airlines stated that related AMM tasks are equivalent 
procedures for performing the operational test referred to in paragraph 
(f) of the previous NPRM (73 FR 32255, June 6, 2008). This commenter 
stated that clarification should be provided as to whether using the 
procedures specified in AMM Task 28-22-00-710-801 meets the intent of 
paragraph (f) of the previous NPRM. This commenter also noted that, 
because the AMM task is already contained in Task Card 28-050-00-01, 
and has a repetitive interval identified in the MPD, the repetitive 
action should be removed from the previous NPRM and addressed as a CMR.
    We disagree with the commenter's request. The manifold test (Task 
28-22-00-710-801) is not equivalent to the operational test (Task 28-
22-00-710-802) for the purposes of this proposed action. The positive 
internal fuel line pressure applied during the manifold test does not 
simulate the same conditions encountered during fuel suction feed 
(i.e., vacuum), and may mask a failure. We have not changed the 
supplemental NPRM in this regard.

Requests To Clarify if Engine Fuel Suction Feed Test Is Allowed in Lieu 
of the Operational Test

    KLM, A4A on behalf of its member DAL, and Sun Country Airlines 
asked that we clarify the engine fuel suction feed test procedure in 
the AMM as an option to performing the operational test. KLM suggested 
that we consider the test procedure done per AMM Task 28-22-15-710-801 
as an alternative test. KLM added that this alternative test is allowed 
by MPD 28-050-00, and is mentioned in Task Card 28-050-00-01. KLM noted 
that the advantage of this alternative test is that it can be performed 
without fuel in the tank; therefore, if the tanks are still open during 
the test and the test fails, easy access is gained to the damaged area. 
DAL stated that the intention of the previous NPRM (73 FR 32255, June 
6, 2008) seems to be performing an engine fuel suction feed test, so 
paragraph (f) of the previous NPRM should be clarified to include that 
test as an option. The commenters stated that the engine fuel suction 
feed test in the AMM and the operational test in the previous NPRM are 
equivalent tests and are allowed per Task Card 28-050-00-01.
    We agree to provide clarification. As noted previously, the 
manifold test (Task 28-22-00-710-801) is not equivalent to the 
operational test (Task 28-22-00-710-802) for the purposes of this 
proposed action. The positive internal fuel line pressure applied 
during the manifold test does not simulate the same conditions 
encountered during fuel suction feed (i.e., vacuum), and may mask a 
failure. Therefore, we have not changed the supplemental NPRM in this 
regard.

Request To Include Corrective Action

    Boeing and CAL asked that corrective action be included in the 
proposed requirements of the previous NPRM (73

[[Page 37833]]

FR 32255, June 6, 2008). CAL recommended that paragraph (f) of the 
previous NPRM be changed to also ``correct any discrepancy identified 
as necessary, before further flight. Refer to 737NG FIM 28-22 task 
819.'' CAL noted that the fault isolation manual (FIM) should be 
considered as an ICA that is an approved method by the Manager, Seattle 
Aircraft Certification Office (ACO), FAA. Boeing stated that the 
requirement in the preamble of the previous NPRM (FAA's Conclusions) 
for additional testing would be better described as performing 
corrective action in case the engine suction feed operational test is 
not successful.
    We agree with the requests to include corrective action for this 
supplemental NPRM. Since the current revision of the AWL does not 
include the corrective action, paragraph (g) of this supplemental NPRM 
specifies that corrective action for findings from the operational 
tests be done in accordance with a method approved by the Manager, 
Seattle ACO, FAA.

Requests To Revise Repetitive Interval

    CAL, Qantas Airways Ltd (Qantas), and Boeing asked that we revise 
the compliance time for the repetitive operational test proposed by 
paragraph (f) of the previous NPRM (73 FR 32255, June 6, 2008).
    CAL asked that the interval be extended from 7,500 flight hours to 
2C-check or 12,500 flight hours, whichever occurs first. As 
justification for extending the repetitive interval, CAL stated that 
fleet history revealed no reported engine flameout events or related 
operational discrepancies.
    Qantas and Boeing asked that the repetitive interval be changed to 
7,500 flight hours or 36 months, whichever occurs first. Qantas and 
Boeing stated that, for low-utilization airplanes, it would take more 
than 10 years of operation before an operational test would be 
necessary.
    We agree to revise the compliance times. We have added new 
paragraph (g) to this supplemental NPRM to include an initial test 
within 7,500 flight hours or 36 months, whichever occurs first after 
the maintenance program is revised. We have also included a repetitive 
interval of 7,500 flight hours or 36 months, whichever occurs first.

Request To Include Warning Information

    CAL suggested that the Boeing service manuals include a critical 
design configuration control limitations (CDCCL) warning identification 
statement to alert maintenance personnel of the importance of 
regulatory compliance, as well as the configuration control requirement 
of the task. CAL did not include any justification for this request.
    We agree that a CDCCL warning statement would serve as direct 
communication to maintenance personnel that there is an AD associated 
with certain maintenance actions, but do not find this additional 
measure necessary to adequately address the unsafe condition. We have 
made no change to the supplemental NPRM in this regard.

Request To Clarify the Reason for the Unsafe Condition

    Boeing asked that we clarify the unsafe condition identified in the 
previous NPRM (73 FR 32255, June 6, 2008) by specifying that the AD 
results from a report of an in-service occurrence of total loss of 
pressure of the fuel feed system, followed by loss of fuel system 
suction feed capability on one engine.
    We agree to clarify the unsafe condition. We have revised the 
Summary section and paragraph (e) of this supplemental NPRM 
accordingly.

Request To Revise Costs of Compliance Section

    A4A, on behalf of its member DAL, asked that the cost estimate be 
changed. DAL stated that the cost estimate specified in the previous 
NPRM (73 FR 32255, June 6, 2008) is too low, and asked that it be 
changed. DAL noted that $80 per product based on 1 work hour per 
product does not include the cost of fuel. DAL estimated that the cost 
of fuel alone would be $83 per test occurrence; for the 71 airplanes in 
its fleet, this translates to a cost of $5,893 per test cycle.
    We do not agree that the cost estimate should be changed. ADs, 
which require specific actions to address specific unsafe conditions, 
appear to impose costs that would not otherwise be borne by operators. 
However, because of the general obligation of operators to maintain and 
operate their airplanes in an airworthy condition, this appearance is 
deceptive. Attributing those fuel costs solely to the issuance of this 
AD is unrealistic because, in the interest of maintaining and operating 
safe airplanes, prudent operators would accomplish the required actions 
even if they were not required to do so by the AD. In any case, we have 
determined that direct and incidental costs are still outweighed by the 
safety benefits of the AD. Except for updating the hourly labor rate to 
$85, we have made no further change to the cost estimates provided in 
this supplemental NPRM.

FAA's Determination

    We are proposing this supplemental NPRM because we evaluated all 
the relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design. Certain changes described above expand the scope of the 
original NPRM (73 FR 32255, June 6, 2008). As a result, we have 
determined that it is necessary to reopen the comment period to provide 
additional opportunity for the public to comment on this supplemental 
NPRM.

Proposed Requirements of the Supplemental NPRM

    This supplemental NPRM revises the previous NPRM (73 FR 32255, June 
6, 2008); by proposing to require repetitive operational tests of the 
engine fuel suction feed of the fuel system, and would require other 
related testing and corrective action if necessary.

Explanation of Change to Costs of Compliance

    Since issuance of the previous NPRM (73 FR 32255, June 6, 2008), we 
have increased the labor rate used in the Costs of Compliance from $80 
per work-hour to $85 per work-hour. The Costs of Compliance 
information, below, reflects this increase in the specified labor rate.

Costs of Compliance

    We estimate that this proposed AD would affect 1,080 airplanes of 
U.S. registry. We estimate the following costs to comply with this 
proposed AD:

                                                 Estimated Costs
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                                                                                    Cost per       Cost on U.S.
                    Action                                Labor cost                product         operators
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Operational Test.............................  1 work-hour x $85 per hour =                $85          $91,800
                                                $85.
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[[Page 37834]]

    We have received no definitive data that would enable us to provide 
a cost estimate for the on-condition actions or the optional 
terminating action specified in this AD.

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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2008-0617; Directorate Identifier 
2007-NM-354-AD.

(a) Comments Due Date

    We must receive comments by August 9, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any 
category, with a date of issuance of the original airworthiness 
certificate or the date of issuance of the original export 
certificate of airworthiness before March 22, 2011.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 2800, Aircraft Fuel System.

(e) Unsafe Condition

    This AD was prompted by a report of an in-service occurrence of 
total loss of boost pump pressure of the fuel feed system, followed 
by loss of fuel system suction feed capability on one engine, and 
in-flight shutdown of the engine. We are issuing this AD to detect 
and correct loss of the engine fuel suction feed capability of the 
fuel system, which in the event of total loss of the fuel boost 
pumps could result in dual engine flameout, inability to restart the 
engines, and consequent forced landing of the airplane.

(f) Compliance

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

(g) Initial/Repetitive Operational Tests

    Within 7,500 flight hours or 36 months after the effective date 
of this AD, whichever occurs first: Do the initial operational test 
identified in AWL No. 28-AWL-101, Engine Fuel Suction Feed 
Operational Test, of Section E., AWLS--Fuel Systems of Section 9, 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D626A001-CMR, Revision August 2011, of Boeing 
737-600/700/700C/800/900/900ER Maintenance Planning Data (MPD) 
Document. Repeat the test thereafter at intervals not to exceed 
7,500 flight hours or 36 months, whichever is earlier. If the test 
is not considered successful, as specified in AWL No. 28-AWL-101, 
before further flight, perform all related testing and corrective 
actions, using a method approved in accordance with the procedures 
specified in paragraph (h) of this AD. Thereafter, except as 
provided in paragraph (h) of this AD, no alternative procedure or 
repeat test intervals will be allowed.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(i) Related Information

    (1) For more information about this AD, contact Sue Lucier, 
Aerospace Engineer, Propulsion Branch, ANM-140S, 1601 Lind Avenue 
SW., Renton, Washington 98057-3356; phone: 425-917-6438; fax: 425-
917-6590; email: suzanne.lucier@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, Washington. For information on the 
availability of this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on June 18, 2012.
John P. Piccola,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-15469 Filed 6-22-12; 8:45 am]
BILLING CODE 4910-13-P


