[Federal Register Volume 61, Number 35 (Wednesday, February 21, 1996)]
[Rules and Regulations]
[Pages 6501-6503]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3150]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-155-AD; Amendment 39-9514; AD 96-04-03]
Airworthiness Directives; Boeing Model 737-200 and -200C
Airplanes Equipped With dB Partners Hush Kits Installed in Accordance
With Supplemental Type Certificate (STC) SA5730NM
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 737-200 and -200C airplanes,
that currently requires installation of fail-safe straps onto the
engine inlet attach ring of the nose cowl. This amendment requires
repetitive inspections to detect cracking of the attach ring of the
nose cowl, and replacement of cracked attach rings. Replacement with an
improved attach ring, if accomplished, would terminate the requirement
to inspect the attach ring repetitively. This amendment is prompted by
the development of an improved attach ring that eliminates the need for
repetitive inspections. The actions specified by this AD are intended
to prevent cracking of the attach ring of the nose cowl, which could
result in separation of the nose cowl from the engine following failure
of a turbine blade.
DATES: Effective March 22, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 22, 1996.
The incorporation by reference of Nordam Service Bulletin SB 71-03,
dated March 17, 1995, as listed in the regulations, was approved
previously by the Director of the Federal Register as of May 2, 1995
(60 FR 19157, April 17, 1995).
ADDRESSES: The service information referenced in this AD may be
obtained from The Nordam Group, 624 East 4th Street, Tulsa, Oklahoma
74120. 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: Thomas Rodriguez, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue SW., Renton, Washington; telephone (206) 227-2779; fax
(206) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 95-08-08,
amendment 39-9197 (60 FR 19157, April 17, 1995), which is applicable to
certain Boeing Model 737-200 and -200C airplanes, was published in the
Federal Register on November 22, 1995 (60 FR 57840). The action
proposed to supersede AD 95-08-08 to continue to require installation
of fail-safe straps onto the engine inlet attach ring of the nose cowl.
The action also proposed to require repetitive inspections to detect
cracking of the attach ring of the nose cowl, and replacement of
cracked attach rings. That action also proposed to provide an optional
terminating action
[[Page 6502]]
(installation of an improved attach ring) for the repetitive
inspections.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the two comments received.
Both commenters support the proposed rule.
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.
There are approximately 46 Model 737 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 1
airplane of U.S. registry will be affected by this AD.
The replacement action that is currently required by AD 95-08-08
takes approximately 8 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Required parts will be
provided at no cost to the operator. Based on these figures, the cost
impact of the currently required actions on the sole U.S. operator is
estimated to be $480 per airplane.
The inspection that is required by this new AD will take
approximately 10 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact on U.S. operators of the new requirements of this AD is
estimated to be $600 per airplane, per inspection cycle.
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.
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 removing amendment 39-9197 (60 FR
19157, April 17, 1995), and by adding a new airworthiness directive
(AD), amendment 39-9514, to read as follows:
96-03-04 Boeing: Amendment 39-9514. Docket 95-NM-155-AD. Supersedes
AD 95-08-08, Amendment 39-9197.
Applicability: Model 737-200 and -200C airplanes equipped with
dB Partners Hush Kit having attach ring, part number 65ND-54301-1,
installed in accordance with Supplemental Type Certificate (STC)
SA5730NM, 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 (e) 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 separation of the nose cowl from the engine following
turbine blade failure, accomplish the following:
(a) Within 30 days after May 2, 1995 (the effective date of AD
95-08-08, amendment 39-9197), install fail-safe straps onto the
attach ring, part number (P/N) 65ND-54301-1, of the nose cowl in
accordance with Nordam Service Bulletin SB 71-03, dated March 17,
1995, or Revision 1, dated June 16, 1995.
(b) As of the effective date of this AD: Prior to further flight
following each incident of turbine blade failure, perform a detailed
visual inspection to detect cracking of the attach ring of the nose
cowl. Fail-safe straps must be removed to perform this inspection.
(1) If no cracking is detected, prior to further flight,
reinstall the fail-safe straps in accordance with Nordam Service
Bulletin SB 71-03, dated March 17, 1995, or Revision 1 dated June
16, 1995.
(2) If any cracking is detected, prior to further flight,
accomplish the requirements of either paragraph (b)(2)(i) or
(b)(2)(ii) of this AD.
(i) Replace the cracked attach ring with an attach ring having
P/N 65ND-54301-1 in accordance with STC SA5730NM, and reinstall the
fail-safe strap in accordance with Nordam Service Bulletin SB 71-03,
dated March 17, 1995, or Revision 1, dated June 16, 1995. Repeat the
visual inspection of the attach ring prior to further flight
following each incident of turbine blade failure. Or
(ii) Replace the cracked attach ring with an attach ring having
P/N 65ND-54301-5 in accordance with Nordam Service Bulletin SB 71-
04, Revision 1, dated June 16, 1995. After this replacement is
accomplished, the inspections required by this paragraph may be
terminated.
(c) Installation of an attach ring having P/N 65ND-54301-5
constitutes terminating action for the repetitive inspections
required by paragraph (b) of this AD.
(d) As of May 2, 1995 (the effective date of AD 95-08-08), fail-
safe straps must be installed onto the attach ring, P/N 65ND-54301-
1, of the nose cowl in accordance with Nordam Service Bulletin SB
71-03, dated March 17, 1995, or Revision 1, dated June 16, 1995,
prior to installation of STC SA5730NM on any airplane.
(e) 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.
(f) Special flight permits may be issued in accordance with
sections 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.
(g) The actions shall be done in accordance with the following
Nordam service bulletins, as applicable, which contain the specified
effective pages:
[[Page 6503]]
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Revision level shown on
Service bulletin reference and date Page No. page Date shown on page
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SB 71-03, March 17, 1995............... 1-12 Original................. March 17, 1995.
SB 71-03, Revision 1, June 16, 1995.... 1-11 1........................ June 16, 1995.
12 Original................. March 17, 1995.
SB 71-04, Revision 1, June 16, 1995.... 1, 2 Original................. May 22, 1995.
3-18 1........................ June 16, 1995.
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The incorporation by reference of Nordam Service Bulletin SB 71-
03, dated March 17, 1995, was approved previously by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51 as of May 2, 1995 (60 FR 19157, April 17, 1995). The
incorporation by reference of the remainder of the service documents
listed above is approved 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 The Nordam Group, 624 East 4th Street,
Tulsa, Oklahoma 74120. 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.
(h) This amendment becomes effective on March 22, 1996.
Issued in Renton, Washington, on February 7, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-3150 Filed 2-20-96; 8:45 am]
BILLING CODE 4910-13-P
