DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0720; Product Identifier 2019-NM-117-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2003-09-04 R1, which applies to certain Bombardier, Inc., Model CL-600-
2B19 (Regional Jet series 100 & 440) airplanes. AD 2003-09-04 R1
requires revising the airworthiness limitations for certain structural
inspections; repair if necessary; and submission of inspection findings
to the airplane manufacturer. Since the FAA issued AD 2003-09-04 R1,
the agency determined that additional airplanes are affected, that new
or more restrictive airworthiness limitations are necessary, and that
the compliance time must be revised to include a phase-in time for
certain tasks. This proposed AD would revise the applicability to
include additional airplanes; revise certain compliance times; and
require revising the existing maintenance or inspection program, as
applicable, to incorporate new or more restrictive airworthiness
limitations. 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 December 16,
2019.

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., 200 Cote-Vertu Road West, Dorval, Quebec
H4S 2A3, Canada; North America toll-free telephone 1-866-538-1247 or
direct-dial telephone 1-514-855-2999; 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-2019-
0720; 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, the regulatory evaluation, 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 Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 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-2019-0720;
Product Identifier 2019-NM-117-AD" at the beginning of your comments.
The agency specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. The
FAA will consider all comments received by the closing date and may
amend this proposed AD based on those comments.

The FAA will post all comments received, without change, to http://www.
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.

Discussion

The FAA issued AD 2003-09-04 R1, Amendment 39-13305 (68 FR 54985,
September 22, 2003) ("AD 2003-09-04 R1"), for certain Bombardier
Model CL-600-2B19 (Regional Jet series 100 & 440) airplanes. (AD 2003-
09-04 R1 revised AD 2003-09-04, Amendment 39-13133 (68 FR 22587, April
29, 2003).) AD 2003-09-04 R1 requires revising the airworthiness
limitations section of the Instructions for Continued Airworthiness to
incorporate new structural inspection intervals for the pressure floor
skin of the center fuselage at fuselage stations 460 and 513; repair if
necessary; and submission of inspection findings to the airplane
manufacturer. AD 2003-09-04 R1 resulted from a report of fatigue cracks
on the pressure floor skin of the center fuselage at fuselage stations
460 and 513. The FAA issued AD 2003-09-04 R1 to address fatigue cracks
of the pressure floor skin of the center fuselage at fuselage stations
460 and 513, which could result in failure of the pressure floor skin
and consequent rapid decompression of the airplane during flight.

Actions Since AD 2003-09-04 R1 Was Issued

Since the FAA issued AD 2003-09-04 R1, the agency has determined
that the applicability must be revised to include additional airplane
serial numbers, that new or more restrictive airworthiness limitations
are necessary, and that the compliance time must be revised to include
a phase-in time for certain airworthiness limitations tasks.

Transport Canada Civil Aviation (TCCA), which is the civil aviation
authority for Canada, has issued Canadian AD CF-2002-39R2, dated August
15, 2019 (referred to after this as the Mandatory Continuing
Airworthiness Information, or "the MCAI"), to correct an unsafe
condition for certain Bombardier Model CL-600-2B19 (Regional Jet series
100 & 440) airplanes.

This proposed AD was prompted by a report of fatigue cracks on the
pressure floor skin of the center fuselage at fuselage stations 460 and
513. The FAA is proposing this AD to address such fatigue cracks, which
could result in failure of the pressure floor skin and consequent rapid
decompression of the airplane during flight. See the MCAI for
additional background information.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Bombardier CL-600-2B19 Temporary Revision 2B-
2265, dated July 19, 2018, to Appendix B--Airworthiness Limitations, of
Part 2 of the Bombardier Maintenance Requirements Manual; and
Bombardier CL-600-2B19 Temporary Revision 2B-2266, dated July 19, 2018,
to Appendix B--Airworthiness Limitations, of Part 2 of the Bombardier
Maintenance Requirements Manual. These temporary revisions describe
airworthiness limitations for inspections of the pressure floor skin.
These documents are distinct since they describe different
airworthiness limitations.

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 agency has been notified of the unsafe condition described in the
MCAI and service information referenced above. The FAA is proposing
this AD because the agency 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 require revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations.

This AD requires 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 (k)(1) of this proposed AD.
The request should include a description of changes to the required
actions that will ensure the continued damage tolerance of the affected
structure.

Differences Between This Proposed AD and the MCAI or Service Information

The MCAI specifies that if there are findings from the
airworthiness limitations section (ALS) inspection tasks, corrective
actions must be accomplished in accordance with Bombardier maintenance
documentation. However, this proposed AD does not include that
requirement. Operators of U.S.-registered airplanes are required by
general airworthiness and operational regulations to perform
maintenance using methods that are acceptable to the FAA. The FAA
considers those methods to be adequate to address any corrective
actions necessitated by the findings of ALS inspections required by
this proposed AD.

Costs of Compliance

The FAA estimates that this proposed AD would affect 37 airplanes
of U.S. registry.

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).

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.

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 and associated appliances to the
Director of the System Oversight Division.

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 removing Airworthiness Directive (AD)
2003-09-04 R1, Amendment 39-13305 (68 FR 54985, September 22, 2003),
and adding the following new AD: