Rule2021-26331
Airworthiness Directives; Learjet Inc. Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 6, 2021
Effective
January 10, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain Learjet Inc. Model 45 airplanes. This AD was prompted by a report of a fuel leak due to a cracked fuel line between the engine fuel control and the engine fuel flow meter. This AD requires replacing the existing fuel flow meter bracket assembly with a redesigned bracket assembly and reporting information to the FAA. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 231 (Monday, December 6, 2021)</title>
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[Federal Register Volume 86, Number 231 (Monday, December 6, 2021)]
[Rules and Regulations]
[Pages 68887-68889]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-26331]
[[Page 68887]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0660; Project Identifier AD-2021-00398-T;
Amendment 39-21809; AD 2021-23-11]
RIN 2120-AA64
Airworthiness Directives; Learjet Inc. Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Learjet Inc. Model 45 airplanes. This AD was prompted by a
report of a fuel leak due to a cracked fuel line between the engine
fuel control and the engine fuel flow meter. This AD requires replacing
the existing fuel flow meter bracket assembly with a redesigned bracket
assembly and reporting information to the FAA. The FAA is issuing this
AD to address the unsafe condition on these products.
DATES: This AD is effective January 10, 2022.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of January 10,
2022.
ADDRESSES: For service information identified in this final rule,
contact Learjet Inc., One Learjet Way, Wichita, KS 67209; phone: (316)
946-2000; email: <a href="/cdn-cgi/l/email-protection#6302004d0a0017230206110c4d010c0e010211070a06114d000c0e"><span class="__cf_email__" data-cfemail="9ffefcb1f6fcebdffefaedf0b1fdf0f2fdfeedfbf6faedb1fcf0f2">[email protected]</span></a>; website: <a href="https://businessaircraft.bombardier.com/en/aircraft/Learjet.html">https://businessaircraft.bombardier.com/en/aircraft/Learjet.html</a>. You may view
this service information at the FAA, Airworthiness Products Section,
Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For
information on the availability of this material at the FAA, call (816)
329-4148. It is also available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0660.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0660; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, any
comments received, and other information. The address for Docket
Operations is U.S. Department of Transportation, Docket Operations, M-
30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue
SE, Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Thomas Teplik, Aviation Safety
Engineer, Wichita ACO Branch, FAA, 1801 S. Airport Road, Wichita, KS
67209; phone: (316) 946-4196; email: <a href="/cdn-cgi/l/email-protection#e5918d8a888496cb918095898c8ea5838484cb828a93"><span class="__cf_email__" data-cfemail="13677b7c7e72603d6776637f7a78537572723d747c65">[email protected]</span></a> or <a href="/cdn-cgi/l/email-protection#b6e1dfd5dedfc2d79bf5f9e5f6d0d7d798d1d9c0"><span class="__cf_email__" data-cfemail="acfbc5cfc4c5d8cd81efe3ffeccacdcd82cbc3da">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain serial numbered
Learjet Inc. Model 45 (Learjet 40), Model 45 (Learjet 45), Model 45
(Learjet 70), and Model 45 (Learjet 75) airplanes. The NPRM published
in the Federal Register on August 13, 2021 (86 FR 44660). The NPRM was
prompted by a report of a fuel leak due to a cracked fuel line between
the engine fuel control and the engine fuel flow meter on a Model 45
(Learjet 45) airplane. Further analysis of the fleet of all the 45
models revealed similar failures in this area including the following:
16 fuel line failures, 2 instances of multiple inlet attaching bolts
breaking, 9 leaking fuel controls, a broken gearbox strut, 4 cracked
No. 6 bearing oil supply lines, and 7 cracked engine oil tanks. The FAA
evaluated the flammable fluid leaks and broken parts and determined
that they may have resulted from vibration. In the NPRM, the FAA
proposed to require replacing the existing fuel flow meter bracket
assembly with a redesigned bracket assembly and reporting information
to the FAA. The FAA is issuing this AD to address the unsafe condition
on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received no comments on the NPRM or on the determination of
the costs.
Conclusion
The FAA reviewed the relevant data and determined that air safety
requires adopting this AD as proposed. Accordingly, the FAA is issuing
this AD to address the unsafe condition on these products. This AD is
adopted as proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed the following service documents required for
compliance with this AD:
<bullet> Bombardier Learjet 40 Service Bulletin (SB) SB 40-73-01,
Revision 1;
<bullet> Bombardier Learjet 45 SB 45-73-2, Revision 1;
<bullet> Bombardier Learjet 70 SB 70-73-01, Revision 1; and
<bullet> Bombardier Learjet 75 SB 75-73-01, Revision 2; all
documents dated January 9, 2017.
As applicable to the model configuration specified, each service
bulletin contains procedures for replacing the existing fuel flow meter
bracket assembly with a redesigned fuel flow meter bracket assembly
that has an increased material thickness. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
ADDRESSES.
Differences Between This AD and the Service Information
This AD requires reporting certain maintenance information to the
FAA, where the service information does not. The information provided
in the reports is related to contributing factors that the FAA found
showed a correlation between the reported engine fan vibration levels
and the cracking fuel line between engine fuel control and the engine
fuel flow meter and a correlation between the cracking fuel line and a
certain batch of fan disks. In addition, the FAA found that a
contributing factor could be the susceptibility of the fuel flow meter
bracket assembly to the engine installation vibration. The requested
reporting information allows the FAA to determine whether further
rulemaking action is necessary to mitigate the unsafe condition.
Also, the effectivity of Bombardier Learjet 45 SB 45-73-2, Revision
1, dated January 9, 2017, begins with serial number 45-005. This AD
also applies to airplane serial numbers 45-002 through 45-004 because,
although these three airplanes are not currently in service, they are
subject to the unsafe condition. Thus, it is necessary to include them
in the event they are returned to service.
Costs of Compliance
The FAA estimates that this AD affects 443 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
[[Page 68888]]
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts Cost product operators
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Replacing the bracket assembly.... 4.5 work-hours x $85 $3,895............... $4,277.50 $1,894,932.50
per hour = $382.50.
Reporting and reviewing logbooks.. 9 work-hours x $85 Not Applicable....... 765 338,895
per hour = $765.
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Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to take
approximately 9 hours per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
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.
The FAA is 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
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) Will not affect intrastate aviation in Alaska, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Amendment
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 FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2021-23-11 Learjet Inc.: Amendment 39-21809; Docket No. FAA-2021-
0660; Project Identifier AD-2021-00398-T.
(a) Effective Date
This airworthiness directive (AD) is effective January 10, 2022.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Learjet Inc. Model 45 (Learjet 40), Model 45
(Learjet 45), Model 45 (Learjet 70), and Model 45 (Learjet 75)
airplanes, serial numbers 45-002 through 45-556 and 45-2001 through
45-2146, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 7100, Powerplant
System.
(e) Unsafe Condition
This AD was prompted by a report of a fuel leak due to a cracked
fuel line between the engine fuel control and the engine fuel flow
meter. The FAA is issuing this AD to prevent cracking and failures.
The unsafe condition, if not addressed, could result in an engine
installation fire, which could progress to an uncontrolled fire and
consequent loss of control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Reporting Requirement
Within 60 days after the effective date of this AD, report the
following information, where available, to the Wichita ACO Branch
via email at <a href="/cdn-cgi/l/email-protection#cbbfa3a4a6aab8e5bfaebba7a2a08badaaaae5aca4bd"><span class="__cf_email__" data-cfemail="384c505755594b164c5d48545153785e5959165f574e">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection#adfac4cec5c4d9cc80eee2feedcbcccc83cac2db"><span class="__cf_email__" data-cfemail="0c5b656f6465786d214f435f4c6a6d6d226b637a">[email protected]</span></a>; or by
mail to Wichita ACO Branch, FAA, Attn: Thomas Teplik, 1801 S.
Airport Road, Room 100, Wichita, KS 67209.
(1) Name of the owner; the address of the owner; name of the
organization doing the actions required by this AD; the date the
actions were completed; the name of the person submitting the
report; the address, telephone number, and email of the person
submitting the report.
(2) The fan vibration levels that have been recorded in the
airplane and engine maintenance records since November 1, 2019.
Include the airplane and engine serial numbers.
(3) The date of each vibration level recorded and the associated
hours time-in-service (TIS) for the airplane and each engine.
(4) For each fan vibration level reported, include:
(i) Whether molybdenum coating for the fan was applied per
Temporary Revision 72-494, dated August 15, 2017 (or as subsequently
incorporated into the engine's Inspection/Repair Manual TFE731 (ATA
Number 72-IR-02)).
(ii) If molybdenum coating was applied using a different process
than Temporary Revision 72-494, dated August 15, 2017 (or as
subsequently incorporated into the engine's Inspection/Repair Manual
TFE731 (ATA Number 72-IR-02)), report the process by which the
molybdenum coating was applied and the revision level of the
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document defining the application process for the molybdenum
coating.
Note 1 to paragraph (g)(4): Temporary Revision 72-494, dated
August 15, 2017, specifies applying a dry film lubricant on the
mating surfaces of the fan hub and the fan blades. The lubricating
solid for this dry film lubricant is molybdenum disulfide, which is
referred to in this AD as molybdenum coating.
(5) For each fan vibration level reported, the fan hub serial
number and hours TIS for this fan hub.
(6) Installation date and service bulletin (SB) revision level
for the installation of the bracket assembly with fuel flow meter
and hose if installed before the effective date of this AD.
(7) Any failures of the bracket assembly with fuel flow meter
and hose installed in accordance with any SB listed in paragraph (h)
of this AD or any prior revision of these SBs.
(8) Installation date and SB revision level used for
installation of the fuel control screws within the engine fuel
control in accordance with Honeywell SB TFE731-73-5146.
(9) Any failures of fuel control screws after compliance with
Honeywell SB TFE731-73-5146.
(h) Replacement
Within 12 months after the effective date of this AD or 750
hours TIS after the effective date of this AD, whichever occurs
first, replace the engine fuel flow meter bracket in accordance with
the Accomplishment Instructions, paragraphs 3.A through 3.C, of the
following Bombardier SB, listed in paragraphs (h)(1) through (4) of
this AD, applicable to your airplane model configuration.
(1) Bombardier Learjet 40 SB 40-73-01, Revision 1, dated January
9, 2017.
(2) Bombardier Learjet 45 SB 45-73-2 Revision 1, dated January
9, 2017.
(3) Bombardier Learjet 70 SB 70-73-01 Revision 1, dated January
9, 2017.
(4) Bombardier Learjet 75 SB 75-73-01, Revision 2, dated January
9, 2017.
(i) Credit for Previous Actions
(1) This paragraph provides credit for the action required by
paragraph (h) of this AD, if that action was performed before the
effective date of this AD using Bombardier Learjet 40 SB 40-73-01,
Basic Issue; Bombardier Learjet 45 Service Bulletin SB 45-73-2,
Basic Issue; Bombardier Learjet 70 SB 70-73-01, Basic Issue; or
Bombardier Learjet 75 SB 75-73-01, Basic Issue; all dated October 3,
2016; or Bombardier Learjet 75 SB 75-73-01, Revision 1, dated
October 10, 2016.
(2) To take credit for any previous action, you must comply with
paragraph (g) of this AD within 60 days after the effective date of
this AD.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Wichita ACO Branch, 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 certification office, send it to the attention of the
person identified in paragraph (k) of this AD.
(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.
(k) Related Information
For more information about this AD, contact Thomas Teplik,
Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 S. Airport
Road, Wichita, KS 67209; phone: (316) 946-4196; email:
<a href="/cdn-cgi/l/email-protection#196d717674786a376d7c69757072597f7878377e766f"><span class="__cf_email__" data-cfemail="483c202725293b663c2d38242123082e2929662f273e">[email protected]</span></a>.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference of the service information listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Bombardier Learjet 40 Service Bulletin 40-73-01, Revision 1,
dated January 9, 2017.
(ii) Bombardier Learjet 45 Service Bulletin 45-73-2 Revision 1,
dated January 9, 2017.
(iii) Bombardier Learjet 70 Service Bulletin 70-73-01 Revision
1, dated January 9, 2017.
(iv) Bombardier Learjet 75 Service Bulletin 75-73-01, Revision
2, dated January 9, 2017.
(3) For service information identified in this AD, contact
Learjet Inc., One Learjet Way, Wichita, KS 67209; phone: (316) 946-
2000; email: <a href="/cdn-cgi/l/email-protection#6f0e0c41060c1b2f0e0a1d00410d00020d0e1d0b060a1d410c0002"><span class="__cf_email__" data-cfemail="0c6d6f22656f784c6d697e63226e63616e6d7e6865697e226f6361">[email protected]</span></a>; website: <a href="https://businessaircraft.bombardier.com/en/aircraft/Learjet.html">https://businessaircraft.bombardier.com/en/aircraft/Learjet.html</a>.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 901
Locust, Kansas City, MO 64106. For information on the availability
of this material at the FAA, call (816) 329-4148.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email: <a href="/cdn-cgi/l/email-protection#1573673b7c7b66657076617c7a7b557b7467743b727a63"><span class="__cf_email__" data-cfemail="7016025e191e0300151304191f1e301e1102115e171f06">[email protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on November 1, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-26331 Filed 12-3-21; 8:45 am]
BILLING CODE 4910-13-P
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