Browse: Departments Dates Agencies
Docket ID: [Docket No. 2003-NM-05-AD; Amendment 39-13412; AD 2003-26-13]
RIN ID: RIN 2120-AA64
SUBJECT CATEGORY: Airworthiness Directives; Boeing Model 747 Series Airplanes
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 11, 2004.
DOCUMENT SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires identification of the valves installed on the engine struts as hydraulic supply (fire) shutoff valves for the enginedriven pump, corrective action if necessary, and eventual replacement of discrepant valves with serviceable parts. This action is necessary to prevent leakage of hydraulic (flammable) fluid into an engine fire, which could result in an uncontrolled fire. This action is intended to address the identified unsafe condition.
SUMMARY: Boeing,
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to the comments received.
Support for Proposed AD
Two commenters support the proposed AD.
Request To Add Certain Part Numbers (P/N) for Valve Replacement
One commenter requests that the proposed AD be revised to include hydraulic supply (fire) shutoff valves, P/Ns 1032001 and 1032002. The commenter states that these additional valves are not manufactured by Circle Seal and should be acceptable replacements. This would provide operators with more options when replacing a discrepant Circle Seal valve.
The FAA agrees. Boeing maintenance drawings permit installation of
valve P/Ns 1032001 and 1032002, and Boeing has agreed that those
parts are acceptable for replacement of the discrepant Circle Seal
valves. In addition, we have determined that those valves do not have
the identified unsafe condition. Therefore, we have revised paragraphs
(b)(1)(ii) and (b)(3) of this final rule to include valves, P/Ns 10
32001 and 1032002, as acceptable replacements for the discrepant
Circle Seal valves. Operators should note that Boeing did not include
those valves in Boeing Alert Service Bulletin 74729A2102, dated June
29, 2000 (which was referenced in the proposed AD as the appropriate
source of service information for the inspection and corrective
actions), because they are easily damaged by improper engine shut down
procedures. Such damage necessitates unscheduled replacement of the
valves with serviceable valves of the same design or modified valves
having design features, which help prevent such damage. These design
features were incorporated in valve P/Ns 1032003 and 1032005
(specified in the service bulletin and proposed AD as the appropriate P/N for the replacement valve).
Request To Allow Repetitive Valve Tests Instead of Terminating Replacement
The same commenter requests that the proposed AD be revised to allow operators to continue performing the hydraulic supply (fire) shutoff valve test after four years from valve identification date. The commenter asserts that operational valve replacement should not have a mandatory replacement timetable of four years, and that the option to replace or continue repetitive testing should be left up to the operator to decide.
We do not agree. The Circle Seal valves having P/N S270T0103 have a known design defect. The failure mode in these valves is not a function of time or number of flight cycles. We can better ensure long term continued operational safety by modifications or design changes to remove the source of the problem, rather than by repetitive inspections/testing. Longterm inspections/testing may not provide the degree of safety necessary for the transport airplane fleet. This, coupled with a better understanding of the human factors associated with numerous repetitive inspections, has led us to consider placing less emphasis on special procedures and more emphasis on design improvements. No change to the final rule is necessary in this regard. Request To Revise Paragraph (b)(1)(ii) of Proposed AD
Another commenter, the airplane manufacturer, requests that we revise paragraph (b)(1)(ii) of the proposed AD. The commenter states that paragraph (b)(1)(ii) of the proposed AD does not allow replacement of an inoperative valve with a valve, P/N S270T0103, because that paragraph only refers to paragraph 3.I. of the Accomplishment Instructions of Boeing Alert Service Bulletin 74729A2102. However, paragraph (c) of the proposed AD specifies that a valve, P/N S270T010 3, may be installed if requirements of the AD are accomplished.
We agree. It was our intention to allow a valve, P/N S270T0103, to
be installed if a P/N 1032003 or 1032005 is not available and to
allow the valve to remain installed (until replacement per paragraph
(b)(3) of the AD) as long as it continues to pass the repetitive
hydraulic supply (fire) shutoff valve test, per paragraph 3.J. of the
Accomplishment Instructions of Boeing Alert Service Bulletin 747
29A2102. Therefore, we have revised paragraph (b)(1)(ii) of this final
rule to allow operators to install a valve, P/N S270T0103, as a
replacement as long as the repeated testing is performed per paragraph
3.J. of the service bulletin in accordance with paragraph (b)(2) of this final rule.
[[Page 860]]
Request To Revise Preamble and Paragraph (e) of Proposed AD
The same commenter requests that we make the following changes to the preamble and paragraph (e) of the proposed AD:
[sbull] In the ``Discussion'' section in the preamble of the
proposed AD, identify the model for which the reports indicating
malfunctioning valves were received and on which the failure mode was
discovered during production testing as Boeing Model 737, 757, and 767
series airplanes, not Model 747 series airplanes. The commenter
explains that no reports were received on Model 747 airplanes.
[sbull] In paragraph (e) of the proposed AD, omit the duplicate reference to the ``sections.''
We partially agree with the commenter's requests:
[sbull] We agree that the models for which the original
malfunctioning valve reports on which the failure mode was discovered
were Model 737, 757, and 767 series airplanesnot Model 747 series
airplanes. However, the ``Discussion'' section is not restated in this
final rule, and, therefore, no change to the final rule is necessary in this regard.
[sbull] We do not agree that the second reference to the
``sections'' in paragraph (e) of the proposed AD has been duplicated.
The parenthetical reference to sections 21.197 and 21.199 of the
Federal Aviation Regulations provides the full Code of Federal
Regulations citation for those sections, which is the legal citation. No change to the final rule is necessary in this regard.
Explanation of Change Made to the Cost Impact Section of the Final Rule
Because the cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD, we have revised the Cost Impact section of this final rule to specify an estimate of four work hours for the valve replacement instead of the estimated six work hours specified in the proposed rule for that action. The six work hours specified in the proposed rule included incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Those costs are not typically included in AD rulemaking actions.
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
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. However, for clarity and consistency in this final rule, we have retained the language of the NPRM regarding that material. Change to Labor Rate
We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.
There are approximately 681 airplanes of the affected design in the worldwide fleet. The FAA estimates that 130 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to identify the valve, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $8,450, or $65 per airplane.
The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the 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 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.
Replacing a valve, if required, will take approximately 4 work hours, at an average labor rate of $65 per work hour. Required parts and hydraulic fluid will cost approximately $4,438 per valve. Based on these figures, the cost impact of replacing a valve is estimated to be $4,698.
The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39AIRWORTHINESS 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. Section 39.13 is amended by adding the following new airworthiness directive:
Applicability: Model 747 series airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin 74729A2102, dated June 29, 2000.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an [[Page 861]]
alternative method of compliance in accordance with paragraph (d) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent leakage of hydraulic (flammable) fluid into an engine
fire, which could result in an uncontrolled fire, accomplish the following:
Part Identification
(a) Within 6 months after the effective date of this AD, check
maintenance records or perform a general visual inspection of each
engine strut to determine whether any discrepant valve is installed
as a hydraulic supply (fire) shutoff valve for the enginedriven
pump. A discrepant valve is a Circle Seal valve part number (P/N)
S270T0103 or a valve that cannot be readily identified. Identify
the part in accordance with Boeing Alert Service Bulletin 747
29A2102, dated June 29, 2000. If no discrepant valve is installed, no further work is required by this paragraph.
Note 2: For the purposes of this AD, a general visual inspection
is defined as: ``A visual examination of an interior or exterior
area, installation, or assembly to detect obvious damage, failure,
or irregularity. This level of inspection is made from within
touching distance unless otherwise specified. A mirror may be
necessary to enhance visual access to all exposed surfaces in the
inspection area. This level of inspection is made under normally
available lighting conditions such as daylight, hangar lighting,
flashlight, or droplight and may require removal or opening of
access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.''
Corrective Actions for Discrepant Valves
(b) For any discrepant valve found during the part
identification required by paragraph (a) of this AD:
(1) Within 6 months after the effective date of this AD, do a
hydraulic supply (fire) shutoff valve test, in accordance with
paragraph 3.J. of the Accomplishment Instructions of Boeing Alert Service Bulletin 74729A2102, dated June 29, 2000.
(i) If the valve passes the test, repeat the test in accordance with paragraph (b)(2) of this AD.
(ii) If the valve does not pass the test: Before further flight,
replace the valve with a serviceable valve, P/N S270T0103, 103200
1, 1032002, or a valve identified in paragraph 3.I. of the
Accomplishment Instructions of the service bulletin; and do a
hydraulic supply (fire) shutoff valve test; in accordance with the
Accomplishment Instructions of the service bulletin. Replacement
with a serviceable valve, P/N 1032001, 1032002, or a valve
identified in paragraph 3.I. of the Accomplishment Instructions of
the service bulletin, terminates the repetitive tests required by
paragraph (b)(2) of this AD for that valve. If a P/N S270T0103
valve is installed as a replacement, repeated testing must be
performed per paragraph 3.J. of the Accomplishment Instructions of
the service bulletin in accordance with paragraph (b)(2) of this AD.
(2) Repeat the test specified in paragraph (b)(1) of this AD on
each discrepant valve at intervals not to exceed 6 months, until the
actions specified by paragraph (b)(3) of this AD have been accomplished.
(3) Within 4 years after identifying the valve as required by
paragraph (a) of this AD: Replace each discrepant valve with a
serviceable valve, P/N 1032001, 1032002, or a valve identified
in paragraph 3.I. of the Accomplishment Instructions of the service
bulletin, and do a hydraulic supply (fire) shutoff valve test, in
accordance with the Accomplishment Instructions of the service
bulletin. Replacement with a serviceable valve, P/N 1032001, 10 32002, or a valve identified in paragraph 3.I. of the
Accomplishment Instructions of the service bulletin terminates the
repetitive tests required by paragraph (b)(2) of this AD for that valve.
Part Installation
(c) As of the effective date of this AD, no person may install a
Circle Seal valve P/N S270T0103 on any airplane unless the requirements of this AD are accomplished for that valve.
Alternative Methods of Compliance
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA. Operators shall submit their requests through an
appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
Sec. Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.
Incorporation by Reference
(f) Unless otherwise specified in this AD, the actions shall be
done in accordance with Boeing Alert Service Bulletin 74729A2102,
dated June 29, 2000. This incorporation by reference was approved by
the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. Copies may be obtained from Boeing
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124
2207. Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
Effective Date
(g) This amendment becomes effective on February 11, 2004.
Issued in Renton, Washington, on December 23, 2003. Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 0432 Filed 1604; 8:45 am]
BILLING CODE 491013P
FOR FURTHER INFORMATION CONTACT Kenneth W. Frey, Aerospace Engineer, Systems and Equipment Branch, ANM130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055 4056; telephone (425) 9176468; fax (425) 9176590.
14 CFR Part 39 40 CFR Part 52 14 CFR Part 71 33 CFR Part 165 50 CFR Part 679 47 CFR Part 73 26 CFR Part 1 40 CFR Part 180 33 CFR Part 117 50 CFR Part 17 44 CFR Part 67 50 CFR Part 648 14 CFR Part 97 33 CFR Part 100 40 CFR Part 63 50 CFR Part 622 44 CFR Part 65 50 CFR Part 660 26 CFR Part 301 39 CFR Part 111 40 CFR Part 300 6 CFR Part 5 40 CFR Part 271 47 CFR Part 64 40 CFR Parts 52 and 81 50 CFR Part 665 44 CFR Part 64 10 CFR Part 50 49 CFR Part 571 47 CFR Part 76