DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0913; Project Identifier MCAI-2020-00971-T]
RIN 2120-AA64

Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate
Previously Held by Bombardier, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2015-05-03, which applies to certain MHI RJ Aviation ULC Model CL-600-
2B19 (Regional Jet Series 100 & 440) airplanes. AD 2015-05-03 requires
revising the maintenance or inspection program, as applicable, to
incorporate new or revised maintenance requirements and airworthiness
limitations, and incorporating structural repairs and modifications to
preclude widespread fatigue damage (WFD). Since the FAA issued AD 2015-
05-03, the FAA has determined that new or more restrictive
airworthiness limitations are necessary, as well as the corresponding
structural repairs and modifications to preclude WFD. This proposed AD
would require revising the existing maintenance or inspection program,
as applicable, to incorporate new or more restrictive airworthiness
limitations and would require incorporating structural repairs and
modifications to preclude WFD. 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 November
30, 2020.

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 https://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 MHI RJ
Aviation ULC, 12655 Henri-Fabre Blvd., Mirabel, Quebec J7N 1E1
Canada; Widebody Customer Response Center North America toll-free
phone: +1-844-272-2720 or direct-dial phone: +1-514-855-8500; fax: +1-
514-855-8501; email: thd.crj@mhirj.com; internet: https://mhirj.com.
You may view this service information at the FAA, Airworthiness
Products Section, Operational Safety 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 https://www.regulations.
gov by searching for and locating Docket No. FAA-2020-0913;
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. Comments will be
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Andrea Jimenez, Aerospace Engineer,
Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart
Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7330; fax: 516-
794-5531; email: 9-avs-nyaco-cos@faa.gov.

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 the ADDRESSES section. Include "Docket No. FAA-2020-0913;
Project Identifier MCAI-2020-00971-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
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this proposed AD.

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
Andrea Jimenez, Aerospace Engineer, Airframe and Propulsion Section,
FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY
11590; phone: 516-228-7330; fax: 516-794-5531; email: 9-avs-nyaco-cos@faa.
gov. Any commentary that the FAA receives which is not specifically
designated as CBI will be placed in the public docket for this rulemaking.

Discussion

The FAA issued AD 2015-05-03, Amendment 39-18113 (80 FR 13758,
March 17, 2015) ("AD 2015-05-03"), for certain MHI RJ Aviation ULC
Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. AD 2015-
05-03 requires revising the maintenance or inspection program, as
applicable, to incorporate new or revised maintenance requirements and
airworthiness limitations, and incorporating structural repairs and
modifications to preclude WFD. AD 2015-05-03 resulted from reports of
cracking on the skin panels and skin splice joints and angles at
certain stringers at various locations between certain fuselage
stations. The FAA issued AD 2015-05-03 to address WFD, which could
adversely affect the structural integrity of the airplane.

Actions Since AD 2015-05-03 Was Issued

Since the FAA issued AD 2015-05-03, the FAA has determined that new
or more restrictive airworthiness limitations are necessary, as well as
the corresponding structural repairs and modifications to preclude WFD.

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2014-07R1, dated July
13, 2020 (referred to after this as the Mandatory Continuing
Airworthiness Information, or "the MCAI"), to correct an unsafe
condition for certain MHI RJ Aviation ULC Model CL-600-2B19 (Regional
Jet Series 100 & 440) airplanes. You may examine the MCAI in the AD
docket on the internet at https://www.regulations.gov by searching for
and locating Docket No. FAA-2020-0913.

This proposed AD was prompted by a determination that new or more
restrictive airworthiness limitations are necessary, as well as the
corresponding structural repairs and modifications to preclude WFD. The
manufacturer discovered inconsistencies between the Engineering
Structure Reports and Maintenance Tasks for the inspection of fuselage
skin longitudinal splices along a certain stringer. The FAA is
proposing this AD to address WFD, which could adversely affect the
structural integrity of the airplane. See the MCAI for additional
background information.

Related Service Information Under 1 CFR Part 51

MHI RJ Aviation has issued Bombardier Temporary Revision 2B-2280,
dated June 12, 2020. This service information, among other actions,
describes airworthiness limitation (AWL) task 53-41-207, which
specifies airworthiness limitations and inspections for fuselage and
longitudinal skin splices at stringer (STR) 6 and 20.

This proposed AD would also require the following service
information, which the Director of the Federal Register approved for
incorporation by reference as of April 21, 2015 (80 FR 13758, March 17,
2015).

AWL Task 53-41-110, Longitudinal Str. 6 splice butt strap
at Str. 6, FS409.0 to FS617.0, of Appendix B, Airworthiness
Limitations, of Part 2, Airworthiness Requirements, Revision 9, dated
June 10, 2013, of the Bombardier CL-600-2B19 Maintenance Requirements
Manual, CSP A-053.

AWL Task 53-41-204, Frame splice angles at STR 6 and 20,
of Appendix B, Airworthiness Limitations, of Part 2, Airworthiness
Requirements, Revision 9, dated June 10, 2013, of the Bombardier CL-
600-2B19 Maintenance Requirements Manual, CSP A-053.

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

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with the State of Design Authority,
the FAA has been notified of the unsafe condition described in the MCAI
and service information referenced above. The FAA is proposing this AD
because the FAA evaluated all the relevant information and determined
the unsafe condition described previously is likely to exist or develop
on other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would retain certain requirements of AD 2015-05-03.
This proposed AD would require revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations and would require incorporating
structural repairs and modifications to preclude WFD.

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
(n)(1) of this proposed AD.

Costs of Compliance

The FAA estimates that this proposed AD affects 431 airplanes of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

The FAA estimates the total cost per operator for the retained
actions from AD 2015-05-03 to be $7,650 (90 work-hours x $85 per work-
hour).

The FAA has determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although the
agency recognizes that this number may vary from operator to operator.
In the past, the agency has estimated that this action takes 1 work-
hour per airplane. Since operators incorporate maintenance or
inspection program changes for their affected fleet(s), the FAA has
determined that a per-operator estimate is more accurate than a per-
airplane estimate. Therefore, the agency estimates the average total
cost per operator to be $7,650 (90 work-hours x $85 per work-hour).

The FAA has received no definitive data that would enable us to
provide cost estimates for the repairs and modifications specified in
this proposed AD.

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) 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 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:

a. Removing Airworthiness Directive (AD) 2015-05-03, Amendment 39-18113
(80 FR 13758, March 17, 2015); and

b. Adding the following new AD: