[Federal Register: November 14, 2005 (Volume 70, Number 218)]
[Rules and Regulations]
[Page 69069-69071]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14no05-14]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-22169; Directorate Identifier 2005-NM-094-AD;
Amendment 39-14361; AD 2005-23-03]
RIN 2120-AA64
Airworthiness Directives; Learjet Model 23, 24, 24A, 24B, 24B-A,
24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, and 25F
Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E,
24F, 24F-A, 25, 25A, 25B, 25C, 25D, and 25F airplanes. This AD requires
replacement of the spherical accumulator for the main hydraulic system
with a new cylindrical accumulator. For certain airplanes, this AD also
requires modification of the accumulator pressure gauge. This AD
results from reports of the failure of two thrust reverser accumulators
(which are similar to the main hydraulic system's spherical
accumulator) and fatigue cracks found on four thrust reverser
accumulators. We are issuing this AD to prevent failure of the
spherical accumulator for the main hydraulic system, due to fatigue
cracking on the threads, which could result in the loss of hydraulic
power, damage to the surrounding airplane structure, and loss of
airplane control. The failure of the accumulator could also result in
injury to any persons in the surrounding area. The loss of hydraulic
fluid could also leak onto a potential source of ignition and result in
a consequent fire.
DATES: This AD becomes effective December 19, 2005.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of December 19,
2005.
ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov
or in person at the Docket Management Facility, U.S.
Department of Transportation, 400 Seventh Street SW., Nassif Building,
room PL-401, Washington, DC.
Contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942,
for service information identified in this AD.
FOR FURTHER INFORMATION CONTACT: Robert Busto, Aerospace Engineer,
Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft
Certification Office, 1801 Airport Road, Room 100, Mid-Continent
Airport, Wichita, Kansas 67209; telephone (316) 946-4157; fax (316)
946-4107.
SUPPLEMENTARY INFORMATION:
Examining the Docket
You may examine the airworthiness directive (AD) docket on the
Internet at http://dms.dot.gov or in person at the Docket Management
Facility office between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The Docket Management Facility office
(telephone (800) 647-5227) is located on the plaza level of the Nassif
Building at the street address stated in the ADDRESSES section.
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to include an AD that would apply to certain Learjet Model
23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A,
25B, 25C, 25D, and 25F airplanes. That NPRM was published in the
Federal Register on August 23, 2005 (70 FR 49210). That NPRM proposed
to require replacement of the spherical accumulator for the main
hydraulic system with a new cylindrical accumulator. For certain
[[Page 69070]]
airplanes, that proposed AD would also require modification of the
accumulator pressure gauge.
Comments
We provided the public the opportunity to participate in the
development of this AD. We received no comments on the NPRM or on the
determination of the cost to the public.
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have revised this action to clarify the appropriate procedure
for notifying the principal inspector before using any approved AMOC on
any airplane to which the AMOC applies.
Conclusion
We have carefully reviewed the available data, and determined that
air safety and the public interest require adopting the AD with the
change described previously. We have determined that this change will
neither increase the economic burden on any operator nor increase the
scope of the AD.
Costs of Compliance
There are about 434 airplanes of the affected design in the
worldwide fleet. This AD will affect about 242 airplanes of U.S.
registry. The actions will take about 9 to 13 work hours per airplane,
at an average labor rate of $65 per work hour. Required parts will cost
about $1,336 to $1,363 per airplane. Based on these figures, the
estimated cost of the AD for U.S. operators is $464,882 to $534,336, or
$1,921 to $2,208 per airplane.
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 have determined that 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.
We prepared a regulatory evaluation of the estimated costs to
comply with this AD and placed it in the AD docket. See the ADDRESSES
section for a location to examine the regulatory evaluation.
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:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
2005-23-03 Learjet: Amendment 39-14361. Docket No. FAA-2005-22169;
Directorate Identifier 2005-NM-094-AD.
Effective Date
(a) This AD becomes effective December 19, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Learjet Model 23, 24, 24A, 24B, 24B-A,
24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, and 25F
airplanes, certificated in any category; having serial numbers 23-
003 through 23-099 inclusive, 24-100 through 24-284 inclusive, and
25-003 through 25-153 inclusive.
Unsafe Condition
(d) This AD results from reports of the failure of two thrust
reverser accumulators (which are similar to the main hydraulic
system's accumulator) and fatigue cracks found on four thrust
reverser accumulators. We are issuing this AD to prevent failure of
the spherical accumulator for the main hydraulic system, due to
fatigue cracking on the threads, which could result in the loss of
hydraulic power, damage to the surrounding airplane structure, and
loss of airplane control. The failure of the accumulator could also
result in injury to any persons in the surrounding area. The loss of
hydraulic fluid could also leak onto a potential source of ignition
and result in a consequent fire.
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.
Replacement
(f) Within 60 days after the effective date of this AD, replace
the spherical accumulator having part number (P/N) 2380025-() or P/N
2380167-() with a new cylindrical accumulator having P/N 2497202-
801, in accordance with the Accomplishment Instructions of
Bombardier Alert Service Bulletin A23/24/25-29-4, Revision 1, dated
January 17, 2005.
Concurrent Action
(g) For airplanes having serial numbers 23-003 through 23-014
inclusive: Prior to or concurrently with the actions in Bombardier
Alert Service Bulletin A23/24/25-29-4, Revision 1, dated January 17,
2005, relocate the accumulator pressure gauge in accordance with
Learjet Service Kit SK23-215, dated April 4, 1966.
Parts Installation
(h) As of the effective date, no spherical accumulator having P/
N 2380025-() or P/N 2380167-() may be installed on any airplane.
Previous Actions
(i) Replacements done before the effective date of this AD in
accordance with Bombardier Alert Service Bulletin A23/24/25-29-4,
dated August 20, 2004, are acceptable for compliance with the
requirements of paragraph (f) of this AD.
No Reporting Required
(j) Although the service bulletin referenced in this AD
specifies to submit certain information to the manufacturer, this AD
does not include that requirement.
Alternative Methods of Compliance (AMOCs)
(k)(1) The Manager, Wichita 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) Before using any AMOC approved in accordance with Sec.
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.
[[Page 69071]]
Material Incorporated by Reference
(l) You must use Bombardier Alert Service Bulletin A23/24/25-29-
4, Revision 1, dated January 17, 2005; and Learjet Service Kit SK23-
215, dated April 4, 1966; as applicable, to perform the actions that
are required by this AD, unless the AD specifies otherwise. (The
issue date of Learjet Service Kit SK23-215 is located only on the
first and last pages of the document.) The Director of the Federal
Register approved the incorporation by reference of this document in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Learjet,
Inc., One Learjet Way, Wichita, Kansas 67209-2942, for a copy of
this service information. You may review copies at the Docket
Management Facility, U.S. Department of Transportation, 400 Seventh
Street SW., room PL-401, Nassif Building, Washington, DC; on the
Internet at http://dms.dot.gov; or at the National Archives and
Records Administration (NARA). For information on the availability
of this material at the 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 October 26, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-22220 Filed 11-10-05; 8:45 am]
BILLING CODE 4910-13-P