[Federal Register Volume 64, Number 28 (Thursday, February 11, 1999)]
[Rules and Regulations]
[Pages 6791-6793]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3188]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-258-AD; Amendment 39-11035; AD 99-04-11]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, and -800
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 737-600, -700, and -800 series
airplanes, that requires repetitive inspections to detect damage of the
aft strut insulation blanket. This AD also requires eventual
replacement of the insulation blankets with new, improved blankets,
which constitutes terminating action for the requirements of this AD.
This amendment is prompted by reports of damaged aft strut insulation
blankets. The actions specified by this AD are intended to prevent such
damage, which could result in exposure of the lower surface of the
strut to extreme high temperatures, consequent creation of a source of
fuel ignition, and increased risk of a fuel tank explosion and fire.
DATES: Effective March 18, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 18, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Bernie Gonzalez, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2682; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 737-600, -
700, and -800 series airplanes was published in the Federal Register on
October 15, 1998 (63 FR 55343). That action proposed to require
repetitive inspections to detect damage of the aft strut insulation
blanket. That action also proposed to require eventual replacement of
the insulation blankets with new, improved blankets, which would
constitute terminating action for the requirements of the AD.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
[[Page 6792]]
Two commenters express no objection to the proposed rule, and one
commenter supports the proposed rule.
Conclusion
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 as proposed.
Cost Impact
There are approximately 33 Model 737-600, -700, and -800 series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 26 airplanes of U.S. registry will be affected by this
AD.
It will take approximately 1 work hour per airplane to accomplish
the required inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the inspection required by
this AD on U.S. operators is estimated to be $1,560, or $60 per
airplane, per inspection cycle.
It will take approximately 1 work hour per airplane to accomplish
the required replacement, at an average labor rate of $60 per work
hour. Required parts will be provided by the manufacturer at no cost to
the operators. Based on these figures, the cost impact of the
replacement required by this AD on U.S. operators is estimated to be
$1,560, or $60 per airplane.
The cost impact figures discussed above are 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.
Regulatory Impact
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
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.
List of Subjects in 14 CFR Part 39
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 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. Section 39.13 is amended by adding the following new
airworthiness directive:
99-04-11 Boeing: Amendment 39-11035. Docket 98-NM-258-AD.
Applicability: Model 737-600, -700, and -800 series airplanes,
line numbers 1 through 64 inclusive, certificated in any category.
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
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 damage of the aft strut insulation blankets, which
could result in exposure of the lower surface of the strut to
extreme high temperatures, consequent creation of a source of fuel
ignition, and increased risk of a fuel tank explosion and fire,
accomplish the following:
(a) Within 500 flight hours since date of manufacture of the
airplane, or within 30 days after the effective date of this AD,
whichever occurs later, perform a visual or borescope inspection to
detect damage (cracks greater than 2.00 inches and/or separation of
the face sheet) of the aft strut insulation blanket, part number (P/
N) S315A213-42, in accordance with Boeing Alert Service Bulletin
737-54A1038, dated May 7, 1998, as revised by Notice of Status
Change 737-54A1038 NSC 01, dated June 18, 1998. Thereafter, repeat
the visual or borescope inspection at intervals not to exceed 250
flight hours.
(b) If damage (cracks greater than 2.00 inches and/or separation
of the face sheet) of any aft strut insulation blanket is detected
during any inspection required by paragraph (a) of this AD, prior to
further flight, accomplish either paragraph (b)(1) or (b)(2) of this
AD.
(1) Replace any damaged insulation blanket having P/N S315A213-
42 with a new insulation blanket having P/N S315A213-42, in
accordance with Boeing Alert Service Bulletin 737-54A1038, dated May
7, 1998, as revised by Notice of Status Change 737-54A1038 NSC 01,
dated June 18, 1998. Thereafter, repeat the visual or borescope
inspection required by paragraph (a) of this AD at intervals not to
exceed 250 flight hours. Or
(2) Replace any damaged insulation blanket having P/N S315A213-
42 with a new, improved insulation blanket having P/N S315A213-47,
in accordance with Boeing Alert Service Bulletin 737-54A1038, dated
May 7, 1998, as revised by Notice of Status Change 737-54A1038 NSC
01, dated June 18, 1998. Accomplishment of this replacement
constitutes terminating action for the repetitive inspection
requirements of this AD.
(c) Within 18 months after the effective date of this AD,
replace any aft strut insulation blanket having P/N S315A213-42 with
a new, improved insulation blanket having P/N S315A213-47, in
accordance with Boeing Alert Service Bulletin 737-54A1038, dated May
7, 1998, as revised by Notice of Status Change 737-54A1038 NSC 01,
dated June 18, 1998. Accomplishment of this replacement constitutes
terminating action for the requirements of this AD.
(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, Transport Airplane Directorate. 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(e) Special flight permits may be issued in accordance with
Secs. 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.
(f) The actions shall be done in accordance with Boeing Alert
Service Bulletin 737-54A1038, dated May 7, 1998, as revised by
Notice of Status Change 737-54A1038 NSC 01, dated June 18, 1998.
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
[[Page 6793]]
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
(g) This amendment becomes effective on March 18, 1999.
Issued in Renton, Washington, on February 4, 1999.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-3188 Filed 2-10-99; 8:45 am]
BILLING CODE 4910-13-P
