Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

[Federal Register Volume 68, Number 132 (Thursday, July 10, 2003)]
[Rules and Regulations]
[Pages 41059-41062]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17312]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-322-AD; Amendment 39-13221; AD 2003-14-02]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional 
Jet Series 100 & 440) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Bombardier Model CL-600-2B19 (Regional Jet series 
100 & 400) airplanes, that requires a one-time inspection of the aft 
edge of the left and right main windshields to determine whether a 
certain placard is installed, and corrective actions if necessary. This 
action is necessary to prevent stress-related cracking of the 
windshields, and subsequent excessive frequency of abnormal procedures 
specified in the airplane flight manual and/or an emergency descent be 
accomplished, which poses an increased risk to passengers and crew 
members. This action is intended to address the identified unsafe 
condition.

DATES: Effective August 14, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 14, 2003.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Canadiar, Aerospace Group, P.O. Box 
6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This 
information may be examined at the Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, New York Aircraft Certification 
Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Serge Napoleon, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7512; fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Bombardier Model CL-600-
2B19 series airplanes was published in the Federal Register on May 20, 
2002 (67 FR 35461). That action proposed to require a one-time 
inspection of the aft edge of the left and right main windshields to 
determine whether a certain placard is installed, and corrective 
actions if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for Notice of Proposed Rulemaking (NPRM)

    One commenter supports the NPRM.

Request To Withdraw NPRM

    One commenter, the windshield manufacturer, requests that the NPRM 
be withdrawn. The commenter states

[[Page 41060]]

that it has invested a significant amount of time and resources to 
resolve the root cause of cracking of the windshields in service. The 
commenter also states that it has worked closely with the airplane 
manufacturer, operators, and regulatory agencies worldwide to resolve 
the cracking of the windshields in an expeditious manner. The commenter 
strongly believes that the issuance of an NPRM is unwarranted in light 
of its efforts, and the fact that the NPRM only affects, at most, 18 
windshields. The commenter believes that these 18 windshields will be 
modified or replaced no later than December 31, 2002.
    The FAA, while applauding the windshield manufacturer's efforts to 
resolve the cracking of the ply of the windshields, does not agree that 
the NPRM should be withdrawn. In issuing an AD, our intent is not to 
penalize the original equipment manufacturer, but to act in the 
interest of safety, and to ensure that all applicable airplanes conform 
to the corrective actions. While it is understandable that a 
manufacturer would like to minimize any adverse implications regarding 
the safety of its products, we reiterate that the purpose of an AD is 
to correct an identified unsafe condition in an airplane, regardless of 
where it is or what it is caused by. In essence, the AD serves to 
protect the flying public from the consequences of the unsafe 
condition. The AD also serves to protect the manufacturer from the 
liability that would be faced should the unsafe condition not be 
corrected. Until an AD is issued, there is no legal basis for requiring 
U.S. operators to comply with those actions. The AD is the vehicle for 
ensuring, by law, that all affected operators perform the necessary 
actions that will address the identified unsafe condition. In light of 
this, we have determined that this AD is appropriate and warranted.
    Two commenters note that the ``Background Information'' section in 
the preamble of the NPRM states, ``Until a new design for the main 
windshield can be developed by the manufacturer and approved by the 
FAA, operators have requested procedures for modifying the existing 
windshields to address the identified unsafe condition and to improve 
service performance.'' The commenters state that such wording implies 
that a new design for the windshield does not exist.
    The commenters point out that redesigned windshields, Bombardier 
part numbers (P/N) 601R33033-13 and -14 (PPG P/N NP139321-9 and -10 for 
spares), are already available and have been in service for some time 
on recently manufactured airplanes. According to one of the commenters, 
those windshields incorporated certain changes that would minimize the 
potential for structural ply fracture, and that, since their 
introduction, over 525 have been installed on in-service airplanes. One 
of the commenters believes that the identified unsafe condition has 
been successfully addressed by the current production configuration 
(i.e., main windshield units having Bombardier P/N 601R33033-13 or -14) 
and with windows currently in service on which Bombardier Service 
Bulletin 601R-56-004, dated August 16, 2001 (which is referenced in the 
NPRM as the appropriate source of service information for the proposed 
actions), has been done.
    From these comments, we infer that the commenters are requesting 
that the NPRM be withdrawn. We do not agree. As discussed previously, 
this AD is the vehicle for ensuring, by law, that all affected 
operators perform the necessary actions that will address the 
identified unsafe condition.
    The commenters are correct that main windshield units having 
Bombardier P/N 601R33033-13 or -14 have been in service for some time. 
Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, has approved Bombardier Service Bulletin 601R-56-
003, Revision B, dated July 20, 2001, which describes procedures for 
replacing the main windshield units having P/N 601R33033-9 and -10 with 
units having Bombardier P/N 601R33033-13 or -14. However, the service 
bulletin does not specify Bombardier P/N 601R33033-13 or -14 as 
replacement parts for windshields having P/Ns 601R33033-1, -2, -5, and 
-6. In addition, Canadian airworthiness directive CF-2001-35R1, dated 
September 27, 2001, which this AD parallels, does not mandate Service 
Bulletin 601R-56-003. We also find that it will be less costly for 
operators to do the actions required by this AD than the replacement 
specified in Service Bulletin 601R-56-003.
    In light of these findings, we have determined that this AD is 
appropriate and warranted. However, under the provisions of paragraph 
(b) of the final rule, we may consider requests for approval of an 
alternative method of compliance if sufficient data are submitted to 
substantiate that such a design change would provide an acceptable 
level of safety.

Request To Delete Reference to Unsafe Condition

    One commenter requests that all references to ``unsafe condition'' 
in the NPRM be deleted. The commenter states that the main windshield, 
pre-mod configuration, on Model CL-600-2B19 (Regional Jet series 100 & 
400) airplanes does not exhibit an unsafe condition. The commenter also 
states that any unsafe condition would result from the flight deck crew 
being required to operate the airplane in a non-standard manner, not 
from the windshield itself. The commenter is concerned that the 
reference to an ``unsafe condition'' will create a negative impression 
about the Bombardier regional jets.
    We do not agree. The individual ply of the windshields on the 
affected Model CL-600-2B19 (Regional Jet series 100 & 400) airplanes 
has cracked at an unacceptable rate. When such cracking has occurred, 
abnormal procedures specified in the airplane flight manual and/or an 
emergency descent of the airplane have been accomplished at an 
excessive frequency, which exposed the airplane and its occupants to 
unacceptable risks. Furthermore, of the significant number of single-
ply fractures that have occurred, there was one reported case of the 
First Officer's windshield cracking (inner ply) during cruise flight 
and pieces of glass falling on the flightcrew. In addition, TCCA issued 
Canadian airworthiness directive CF-2001-35R1, dated September 27, 
2001, in order to reduce the risk exposure that resulted from airplane 
emergency descent performed as a result of the cracking of the 
windshield ply. TCCA issued that airworthiness directive in order to 
ensure the continued airworthiness of these airplanes in Canada. As 
such, we have determined that, while cracking of the windshield may not 
result in loss of pressurization of the airplane, if the flightcrew 
follows necessary procedures, the need to predictably and routinely 
rely on those procedures, together with the risk of injury to the 
flightcrew, presents an unsafe condition.
    Two commenters do not agree with the statement of unsafe condition 
specified in the NPRM (i.e., to prevent failure of the main windshields 
due to stress-related cracking, which could cause cabin 
depressurization and emergency descent, and adversely affect continued 
safe flight of the airplane). The commenters state that the results of 
fail-safe testing demonstrate the structural integrity of the 
windshield with all three plies fractured. The commenters conclude 
that, while a ply

[[Page 41061]]

fracture may interrupt the normal flight scenario, this stress-cracking 
issue would not result in loss of cabin pressurization.
    Based on the reasons described previously, one of the commenters 
also requests that the word ``failure'' in the statement of unsafe 
condition be replaced with either ``ply fracture'' or ``cracking 
issue.'' The commenter has ``strong concerns'' with the use of the word 
``failure'' to describe the events that occurred. The commenter states 
that the events can more accurately be described as single-ply 
fractures, and that the use of the word failure implies that the 
windshield can result in an unsafe condition.
    From these comments, we infer that the commenter is requesting that 
the unsafe condition specified in the NPRM be revised. We agree. As of 
January 1, 2001, there have been approximately 292 windshield units 
returned to the windshield manufacturer due to structural ply failures. 
None of these windshield breakage incidents resulted in loss of 
pressurization of the airplane. Therefore, we agree with the commenters 
that stress-related cracking of the windshields would not result in 
loss of pressurization. We have revised the final rule to specify the 
unsafe condition as ``to prevent stress-related cracking of the 
windshields, and subsequent excessive frequency of abnormal procedures 
specified in the airplane flight manual and/or an emergency descent be 
accomplished, which poses an increased risk to passengers and crew 
members.''

Request To Revise Applicability

    One commenter requests that PPG P/Ns NP139321-1 through -6 
inclusive be included in the applicability of the NPRM. The commenter 
states such a change will ensure that all parts are covered.
    We do not agree. This AD parallels the applicability of Canadian 
airworthiness directive CF-2001-35R1, dated September 27, 2001, and the 
effectivity of Bombardier Service Bulletin 601R-56-004, dated August 
16, 2001 (which is referenced in this AD as the appropriate source of 
service information for accomplishing the required actions). Paragraph 
1.M, ``Relationship Chart,'' of Bombardier Service Bulletin 601R-56-004 
lists the corresponding PPG P/Ns for the affected Bombardier 
windshields. So, the relationship between the PPG and Bombardier P/Ns 
is well established. Therefore, no change to the final rule is 
necessary in this regard.

Revise Cost Impact

    One commenter states that the work hour estimate for accomplishing 
the modification service bulletin is grossly underestimated. The 
commenter expects to utilize two mechanics with an elapsed time of 
seven hours to accomplish the modification. The commenter also states 
that, contrary to the 339 airplanes listed as affected in the worldwide 
fleet in the Cost Impact section of the NPRM, there are 476 airplanes 
within the potential affected worldwide fleet of which 282 are 
currently under U.S. registry.
    From this comment, we infer that the commenter is requesting that 
the Cost Impact section of the NPRM be revised. We agree partially. We 
do not agree with the commenter that the required inspection takes 
seven hours. As stated in the Cost Impact section of the NPRM, ``The 
cost impact figures discussed in AD rulemaking actions represent only 
the time necessary to perform the specific actions actually required by 
the AD. These figures typically do not include incidental costs, such 
as the time required to gain access and close up, planning time, or 
time necessitated by other administrative actions.'' The specific 
action for this AD is the required inspection, which is also indicated 
in the Cost Impact section. In addition, Bombardier Service Bulletin 
601R-56-004, dated August 16, 2001, which is referenced in this AD as 
the appropriate source of service information for accomplishing the 
required actions, specifies 1 work hour for accomplishing the 
inspection.
    We agree with the commenter that the number of affected airplanes 
is higher than previously approximated; the cost impact information, 
below, has been revised accordingly.

Explanation of Change to Applicability

    We have revised the applicability of the final rule to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models.

Explanation of Change to Labor Rate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, has been 
revised to reflect this increase in the specified hourly labor rate.

Conclusion

    After careful review of the available data, including the comments 
noted above, we have determined that air safety and the public interest 
require the adoption of the rule with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Cost Impact

    There are approximately 476 Model CL-600-2B19 (Regional Jet series 
100 & 400) airplanes of the affected design in the worldwide fleet. We 
estimate that 282 airplanes of U.S. registry will be affected by this 
AD.
    We estimate that it will take approximately 1 work hour per 
airplane to accomplish the inspection, and that the average labor rate 
is $65 per work hour. Based on these figures, the cost impact of the 
required inspection is estimated to be $18,330, or $65 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.
    Should an operator be required to accomplish the corrective 
actions, it will take approximately 1 work hour per airplane to 
accomplish at an average labor rate of $65 per work hour. Required 
parts will be provided by the

[[Page 41062]]

manufacturer at no cost to the operator. Based on these figures, the 
cost impact of the corrective actions is estimated to be $65 per 
airplane.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness 
directive:

AD 2003-14-02 Bombardier, Inc. (Formerly Canadair): Amendment 39-
13221. Docket 2001-NM-322-AD.

    Applicability: Model CL-600-2B19 (Regional Jet series 100 & 400) 
airplanes; certificated in any category; serial numbers 7003 and 
subsequent; equipped with main windshield units, part numbers 
601R33033-1, -2, -5, -6, -9, or -10.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent stress-related cracking of the windshields, and 
subsequent excessive frequency of abnormal procedures specified in 
the airplane flight manual and/or an emergency descent be 
accomplished, which poses an increased risk to passengers and crew 
members; accomplish the following:

Inspection and Corrective Action

    (a) For airplanes equipped with windshield units that have 
accumulated fewer than 2,500 total flight cycles as of the effective 
date of this AD: Within 6 months after the effective date of this 
AD, accomplish a one-time general visual inspection of the aft edges 
of the left and right main windshields to determine whether a 
placard having part number (P/N) CSB-NP-139321-002-1 is installed, 
per the Accomplishment Instructions of Bombardier Service Bulletin 
601R-56-004, dated August 16, 2001.
    (1) If a placard having P/N CSB-NP-139321-002-1 is installed, no 
further action is required by this AD.
    (2) If a placard having a part number other than CSB-NP-139321-
002-1 is installed, before further flight, accomplish the corrective 
actions (including modifying the main windshields by replacing nine 
of the hi-lok pins installed in the lower forward corner of the 
windshields with hi-lok pins having a reduced diameter shank, 
installing a placard having the correct part number on the inner 
retainer near the part identification placard located along the aft 
edge of the window, and replacing any torn or deformed gasket), per 
the Accomplishment Instructions of the service bulletin.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''


    Note 3: Bombardier Service Bulletin 601R-56-004, dated August 
16, 2001, references PPG Industries, Inc., Service Bulletin CSB-NP-
139321-002, Revision C, dated July 31, 2001, as an additional source 
of service information for accomplishment of the modification of the 
left and right main windshields.

Alternative Methods of Compliance

    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, New York Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, New York ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

Special Flight Permit

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (d) The actions shall be done in accordance with Bombardier 
Service Bulletin 601R-56-004, dated August 16, 2001. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Bombardier, Inc., Canadair, 
Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, 
Quebec H3C 3G9, Canada. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, New York Aircraft Certification Office, 
10 Fifth Street, Third Floor, Valley Stream, New York; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

    Note 5: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2001-35R1, dated September 27, 2001.

Effective Date

    (e) This amendment becomes effective on August 14, 2003.

    Issued in Renton, Washington, on July 1, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-17312 Filed 7-9-03; 8:45 am]
BILLING CODE 4910-13-P

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