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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0801; Product Identifier 2017-NM-147-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier, Inc., Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to supersede Airworthiness Directive (AD) 2008-24-
14, which applies to all Bombardier, Inc., Model CL-600-2B19 (Regional
Jet Series 100 & 440) airplanes. AD 2008-24-14 requires revising the
instructions for continued airworthiness to incorporate certain
airworthiness limitations for the main landing gear (MLG) trunnion
fitting assembly. Since we issued AD 2008-24-14, new airworthiness
limitation (AWL) tasks have been introduced with revised inspection,
modification, and safe-life requirements. This proposed AD would
require revising the maintenance or inspection program, as applicable,
to incorporate certain AWLs. It would also require reworking the
trunnion fitting in order to meet new structural safe-life limits. We
are proposing this AD to address the unsafe condition on these
products.
DATES: We must receive comments on this proposed AD by November
15, 2018.
ADDRESSES: You may send comments, using the procedures found in
14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
Fax: 202-493-2251.
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.
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
Bombardier, Inc., 400 Cote-Vertu Road West, Dorval, Quebec
H4S 1Y9, Canada; Widebody Customer Response Center North America toll-
free telephone 1-866-538-1247 or direct-dial telephone 1-514-855-2999;
fax 514-855-7401; email ac.yul@aero.bombardier.com; internet http://
www.bombardier.com. You may view this referenced service information at
the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines,
WA. For information on the availability of this material at the FAA,
call 206-231-3195.
Examining the AD Docket
You may examine the AD docket on the internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2018-0801;
or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this NPRM, the regulatory evaluation, any comments received,
and other information. The street address for the Docket Operations
office (telephone 800-647-5527) is in the ADDRESSES section. Comments
will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Aziz Ahmed, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7329;
fax 516-794-5531.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2018-0801;
Product Identifier 2017-NM-147-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD based on those comments.
We will post all comments we receive, without change, to http://www.
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact
we receive about this proposed AD.
Discussion
We issued AD 2008-24-14, Amendment 39-15758 (73 FR 73785, December
4, 2008) ("AD 2008-24-14"), for all Bombardier, Inc., Model CL-600-
2B19 (Regional Jet Series 100 & 440) airplanes. AD 2008-24-14 requires
revising the Airworthiness Limitations Section (ALS) of the
Instructions for Continued Airworthiness to incorporate new structural
inspection requirements. AD 2008-24-14 resulted from reports of the
discovery of cracks on the MLG trunnion fitting web during fatigue
testing. We issued AD 2008-24-14 to detect and correct fatigue cracking
of the MLG trunnion fitting web.
Actions Since AD 2008-24-14 Was Issued
Since we issued AD 2008-24-14, new AWL tasks have been introduced
with revised inspection, modification, and safe-life requirements, and
we have determined that the trunnion fitting lower flange and both
forward and aft bore holes are also subject to fatigue cracking.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian Airworthiness Directive CF-
2017-27, dated August 2, 2017 (referred to after this as the Mandatory
Continuing Airworthiness Information, or "the MCAI"), to correct an
unsafe condition for certain Bombardier, Inc., Model CL-600-2B19
(Regional Jet Series 100 & 440) airplanes. The MCAI states:
Cracks on the main landing gear (MLG) trunnion fitting web
discovered during fatigue testing led to the issuance of [Canadian]
AD CF-2008-21 [which corresponds to FAA AD 2008-24-14], which
mandated new inspection requirements to ensure that fatigue cracking
of the trunnion web would be detected and corrected.
Additional fatigue test article findings and in-service findings
have shown that the trunnion fitting lower flange and both forward
and aft bore holes are also subject to fatigue cracking. Failure of
the main landing gear trunnion fitting could result in the collapse
of the main landing gear. Bombardier Inc. has decided to implement a
series of design changes to improve the fatigue life of the trunnion
fitting that is now a safe-life assembly.
New and revised Airworthiness Limitation (AWL) tasks for the MLG
trunnion fitting assembly have been introduced in order to require
new inspection, modification, and safe-life requirements. This
[Canadian] AD mandates the incorporation of these new and revised
AWL tasks, and removal of the AWL tasks they replace, to ensure that
fatigue cracking of the MLG trunnion fitting is detected and
corrected. This [Canadian] AD also requires rework of the trunnion
fitting in order to meet new structural safe-life limits.
You may examine the MCAI in the AD docket on the internet at http://
www.regulations.gov by searching for and locating Docket No. FAA-2018-
0801.
Related Service Information Under 1 CFR Part 51
Bombardier has issued the following service information.
Bombardier Service Bulletin 601R-57-046, Revision C, dated
December 20, 2012, describes the cold working of fastener holes in the
MLG trunnion fitting, and related investigative and corrective actions.
Bombardier Service Bulletin 601R-57-047, Revision B, dated
October 2, 2012, describes the installation of forcemate bushings in
the MLG trunnion, and related investigative and corrective actions.
Bombardier Service Bulletin 601R-57-048, Revision C, dated
June 6, 2013, describes the cold working of holes on the web of the MLG
trunnion, and related investigative and corrective actions.
These documents are distinct because they apply to different parts
of the airplane.
The following service information describes certain AWL tasks for
the MLG trunnion fitting assembly.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2237, dated June 19, 2014.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2238, dated June 19, 2014.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2239, dated June 19, 2014.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2241, dated June 19, 2014.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2242, dated June 19, 2014.
Bombardier Maintenance Requirements Manual Temporary
Revision (TR) 2B-2246, dated November 7, 2014.
These documents are distinct because they describe different
actions. 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 section.
FAA's Determination and Requirements of This Proposed AD
This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with the State of Design Authority, we have
been notified of the unsafe condition described in the MCAI and service
information referenced above. We are proposing this AD because we
evaluated all pertinent information and determined an unsafe condition
exists and is likely to exist or develop on other products of the same
type design.
This proposed AD would require revisions to certain operator
maintenance documents to include new actions (e.g., inspections).
Compliance with these actions is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance according to paragraph
(p)(1) of this proposed AD. The request should include a description of
changes to the required actions that will ensure the continued
operational safety of the airplane.
Differences Between This Proposed AD and the Service Information
The MCAI includes the following statement: "If it is not possible
to complete all of the instructions in the SBs . . . due to the
configuration of the aircraft, contact Bombardier Inc. for approved
instructions." This issue is addressed in 14 CFR 39.17, which states
that "If a change in a product affects your ability to accomplish the
actions required by the AD in any way, you must request FAA approval of
an AMOC [alternative method of compliance]. . . ." Since we do not
currently have the authority to delegate AMOC approvals to foreign
civil aviation authorities, the FAA is responsible for these approvals.
Costs of Compliance
We estimate that this proposed AD affects 460 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed
AD:
Estimated Costs
| Action |
Labor cost |
Parts cost |
Cost per product |
Cost on U.S. operators |
| Retained actions |
1 work-hour x $85 per hour =
$85 |
$0 |
$85 |
$39,100 |
| Rework trunnion bearings (new
proposed actions) |
Up to 178 work-hours x $85 per
hour = Up to $15,130 |
38,928 |
Up to $54,058 |
Up to $24,866,680 |
We have determined that revising
the maintenance or inspection
program takes an average of 90 work-hours per operator, although we
recognize that this number may vary from operator to operator. In the
past, we have estimated that this action takes 1 work-hour per
airplane. Since operators incorporate maintenance or inspection program
changes for their affected fleet(s), we have determined that a per-
operator estimate is more accurate than a per-airplane estimate.
Therefore, we estimate the total cost per operator to be $7,650 (90
work-hours x $85 per work-hour).
We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions specified in this proposed
AD.
According to the manufacturer, some or all of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all costs in our cost
estimate.
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.
This proposed AD is issued in accordance with authority delegated
by the Executive Director, Aircraft Certification Service, as
authorized by FAA Order 8000.51C. In accordance with that order,
issuance of ADs is normally a function of the Compliance and
Airworthiness Division, but during this transition period, the
Executive Director has delegated the authority to issue ADs applicable
to transport category airplanes to the Director of the System Oversight
Division.
Regulatory Findings
We 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. Is not a "significant rule" under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
3. Will not affect intrastate aviation in Alaska, and
4. 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 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
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. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD)
2008-24-14, Amendment 39-15758 (73 FR 73785, December 4, 2008), and
adding the following new AD:
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