Proposed Rule2021-15953
Airworthiness Directives; Learjet Inc.
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
July 28, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain Learjet Inc. (Learjet) Model 45 airplanes. This proposed AD was prompted by reports of corrosion found on the upper surface of the lower center wing mid spar splice plate. This proposed AD would require repetitively inspecting the center wing area for corrosion and deterioration of protective treatments, removing any corrosion, and treating any deteriorated areas. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 142 (Wednesday, July 28, 2021)</title>
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[Federal Register Volume 86, Number 142 (Wednesday, July 28, 2021)]
[Proposed Rules]
[Pages 40379-40381]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-15953]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0157; Project Identifier AD-2020-00483-T]
RIN 2120-AA64
Airworthiness Directives; Learjet Inc.
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Learjet Inc. (Learjet) Model 45 airplanes. This proposed AD
was prompted by reports of corrosion found on the upper surface of the
lower center wing mid spar splice plate. This proposed AD would require
repetitively inspecting the center wing area for corrosion and
deterioration of protective treatments, removing any corrosion, and
treating any deteriorated areas. The FAA is proposing this AD to
address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by September
13, 2021.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
<bullet> Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, contact Learjet
Inc., One Learjet Way, Wichita, KS 67209; phone: (316) 946-2000; email:
<a href="/cdn-cgi/l/email-protection#d8b9bbf6b1bbac98b9bdaab7f6bab7b5bab9aabcb1bdaaf6bbb7b5"><span class="__cf_email__" data-cfemail="accdcf82c5cfd8eccdc9dec382cec3c1cecddec8c5c9de82cfc3c1">[email protected]</span></a>; website: https://
<a href="http://businessaircraft.bombardier.com/en/aircraft/Learjet.html">businessaircraft.bombardier.com/en/aircraft/Learjet.html</a>. You may view
this referenced 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.
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-2021-0157; 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 NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Tara Shawn, Aviation Safety Engineer,
Wichita ACO Branch, FAA, 1801 Airport Road, Wichita, KS 67209; phone:
(316) 946-4141; fax: (316) 946-4107; email: <a href="/cdn-cgi/l/email-protection#097d687b68277a61687e67496f6868276e667f"><span class="__cf_email__" data-cfemail="cbbfaab9aae5b8a3aabca58badaaaae5aca4bd">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2021-0157; Project Identifier
AD-2020-00483-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Tara
Shawn, Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 Airport
Road, Wichita, KS 67209. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
Background
In December 2018, the FAA received a report from Learjet of
corrosion found in the center wing area of a Model 45 (Learjet 45)
airplane. Exfoliating corrosion was found on the upper surface of the
lower center wing mid spar splice plate during unrelated maintenance.
The corrosion appeared to extend half way through the thickness of the
splice plate. Since the initial report, the FAA has received 23
additional reports of corrosion from Learjet. The FAA determined areas
of the wing center section are not sealed against the elements; in
addition, the fuselage has drain holes that allow condensation to drain
into the center wing. The accumulation and retention of moisture in the
center wing section may lead to corrosion. This condition, if not
addressed, could result in failure of the wing centerline joint and
lead to partial wing separation with consequent loss of control of the
airplane.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or
[[Page 40380]]
develop on other products of the same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed the following service documents proposed for
compliance with this NPRM:
<bullet> Bombardier Learjet 40 Service Bulletin 40-57-06, Revision
1, dated October, 26, 2020;
<bullet> Bombardier Learjet 45 Service Bulletin 45-57-13, Revision
1, dated October, 26, 2020;
<bullet> Bombardier Learjet 70 Service Bulletin 70-57-02, Revision
1, dated October, 26, 2020; and
<bullet> Bombardier Learjet 75 Service Bulletin 75-57-01, Revision
2, dated April 19, 2021.
As applicable to the model configuration specified, each service
bulletin contains procedures for inspecting for corrosion and
deterioration of protective treatments of the center wing area from the
front spar to the rear spar between wing stations 33.00L to 33.00R,
treating deteriorated areas, and removing any corrosion. Bombardier
Learjet 75 Service Bulletin 75-57-01, Revision 2, dated April 19, 2021,
does not apply to newly- manufactured airplanes, since Learjet added
this inspection to the Airworthiness Limitation Section, which will be
delivered with new airplanes starting at S/N 45-597.
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 the ADDRESSES.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described. This proposed AD would
also require reporting the inspection results to the FAA by email at
<a href="/cdn-cgi/l/email-protection#77201e141f1e03165a3438243711161659101801"><span class="__cf_email__" data-cfemail="5c0b353f3435283d711f130f1c3a3d3d723b332a">[email protected]</span></a>.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 450 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspection....................... 7.50 work-hours x $85 Not applicable..... $637.50 $286,875
per hour = $637.50.
Reporting to FAA................. 1 work-hour x $85 per Not applicable..... 85 38,250
hour = $85.
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The extent of corrosion and deterioration of protective treatments
may vary significantly from airplane to airplane. The FAA has no way of
determining how much damage may be found on each airplane, the cost to
remove the corrosion or treat deteriorated areas (or replacing the
part, if needed), or the number of airplanes that may require repair.
If corrosion is found and removed, the FAA estimates that it would
take 2 work-hours per airplane to provide data to Learjet. With an
average labor rate of $85 per work-hour, the FAA estimates a cost of
$170 per airplane.
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 current 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 up to
3 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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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:
[[Page 40381]]
Learjet Inc.: Docket No. FAA-2021-0157; Project Identifier AD-2020-
00483-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by September 13, 2021.
(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 45-596 and 45-2001 through
45-2146, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 5714, Wing, Center
Box.
(e) Unsafe Condition
This AD was prompted by reports of corrosion found on the upper
surface of the lower center wing mid spar splice plate. The FAA is
issuing this AD to detect and correct corrosion or deterioration of
protective treatments on the center wing area. The unsafe condition,
if not addressed, could result in failure of the wing centerline
joint and lead to partial wing separation with consequent loss of
control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Applicable Service Bulletins
Use the following service bulletins, as applicable to your
airplane model configuration, to perform the actions required by
paragraph (h) of this AD:
(1) Bombardier Learjet 40 Service Bulletin 40-57-06, Revision 1,
dated October 26, 2020;
(2) Bombardier Learjet 45 Service Bulletin 45-57-13, Revision 1,
dated October 26, 2020;
(3) Bombardier Learjet 70 Service Bulletin 70-57-02, Revision 1,
dated October 26, 2020; and
(4) Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 2,
dated April 19, 2021.
(h) Wing Center Spar Inspection, Related Investigative Inspections, and
Corrective Actions
At the applicable initial compliance time specified in paragraph
(h)(1) or (2) of this AD and thereafter at intervals not to exceed 8
years, inspect the center wing area for corrosion and deterioration
of protective treatments and perform all related corrective actions
by following the Accomplishment Instructions, steps 3.A. and 3.B.,
of the applicable service bulletin listed in paragraph (g) of this
AD.
(1) For airplanes with 8 or fewer years since the date of
issuance of the original airworthiness certificate or the date of
issuance of the original export certificate of airworthiness,
whichever date is earlier: Before or upon accumulating 8 years or
within 12 months after the effective date of this AD, whichever
occurs later; or
(2) For airplanes that have accumulated more than 8 years since
the date of issuance of the original airworthiness certificate or
the date of issuance of the original export certificate of
airworthiness, whichever date is earlier: Within 12 months after the
effective date of this AD.
(i) Service Information Exception
Where Bombardier Learjet 40 Service Bulletin 40-57-06, Revision
1, dated October 26, 2020, Bombardier Learjet 45 Service Bulletin
45-57-13, Revision 1, dated October 26, 2020, Bombardier Learjet 70
Service Bulletin 70-57-02, Revision 1, dated October 26, 2020, and
Bombardier Learjet 75 Service Bulletin 75-57-01, Revision 2, dated
April 19, 2021, specify contacting Learjet Inc. for appropriate
action: Before further flight, repair using a method approved in
accordance with the procedures specified in paragraph (l) of this
AD.
(j) Reporting Requirement
Within 30 days after completing the initial inspection required
by paragraph (h) of this AD or within 30 days after the effective
date of this AD, whichever occurs later, submit a report of the
findings (both positive and negative) of the inspection to: <a href="/cdn-cgi/l/email-protection#a4f3cdc7cccdd0c589e7ebf7e4c2c5c58ac3cbd2"><span class="__cf_email__" data-cfemail="c592aca6adacb1a4e8868a9685a3a4a4eba2aab3">[email protected]</span></a>; or Ann Johnson, Wichita ACO Branch, 1801 Airport Road,
Wichita, KS 67209. This reporting requirement is limited to the
initial inspection results only. The report must include: The name
of the owner; the address of the owner; the name of the organization
doing the actions required by this AD; the date the inspection was
completed; the name of the person submitting the report; the
address, telephone number, and email of the person submitting the
report; the airplane serial number; the date of issuance of the
original airworthiness certificate, or the date of issuance of the
original export certificate of airworthiness (whichever date is
earlier); whether protective treatments are deteriorated, and if so,
the location of deteriorated areas; whether corrosion was detected,
and if so, the location of corrosion; and a list of parts replaced
if the level of corrosion required replacement of parts.
(k) Credit for Previous Actions
You may take credit for the initial wing spar inspection
required by the introductory text to paragraph (h) of this AD if you
performed the visual inspection before the effective date of this AD
using Bombardier Learjet 40 Service Bulletin 40-57-06, Basic Issue,
dated February 25, 2019; Bombardier Learjet 45 Service Bulletin 45-
57-13, Basic Issue, dated February 25, 2019; Bombardier Learjet 70
Service Bulletin 70-57-02, Basic Issue, dated February 25, 2019;
Bombardier Learjet 75 Service Bulletin 75-57-01, Basic Issue, dated
February 25, 2019; or Bombardier Learjet 75 Service Bulletin 75-57-
01, Revision 1, dated October 26, 2020.
(1) To take credit for the initial inspection, you must comply
with paragraph (j) of this AD within 30 days after the effective
date of this AD.
(2) You cannot take credit for the recurring inspections, only
the initial inspection.
(l) 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 Related Information.
(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.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair, modification, or alteration required by this AD
if it is approved by a Learjet Inc. Designated Engineering
Representative, or a Unit Member of the Learjet Organization
Designation Authorization, that has been authorized by the Manager,
Wichita ACO Branch, to make those findings. To be approved, the
repair, modification, or alteration method must meet the
certification basis of the airplane, and the approval must
specifically refer to this AD.
(m) Related Information
(1) For more information about this AD, contact Tara Shawn,
Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 Airport
Road, Wichita, KS 67209; phone: (316) 946-4141; fax: (316) 946-4107;
email: <a href="/cdn-cgi/l/email-protection#a3d7c2d1c28dd0cbc2d4cde3c5c2c28dc4ccd5"><span class="__cf_email__" data-cfemail="0b7f6a796a2578636a7c654b6d6a6a256c647d">[email protected]</span></a>.
(2) 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#1273713c7b7166527377607d3c707d7f707360767b77603c717d7f"><span class="__cf_email__" data-cfemail="7312105d1a1007331216011c5d111c1e111201171a16015d101c1e">[email protected]</span></a>; website:
<a href="http://businessaircraft.bombardier.com/en/aircraft/Learjet.html">businessaircraft.bombardier.com/en/aircraft/Learjet.html</a>. You may
view this referenced 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.
Issued on July 21, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-15953 Filed 7-27-21; 8:45 am]
BILLING CODE 4910-13-P
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