Airworthiness directives: Bombardier,
[Federal Register: November 9, 1999 (Volume 64, Number 216)]
[Proposed Rules]
[Page 61039-61042]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09no99-14]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-192-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100) Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 200) series airplanes, that currently requires repetitive inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations, and repair, if necessary. This action would revise the repetitive inspection intervals for certain airplanes, and would require modification or repair, as applicable. This proposal is prompted by the development of a modification that will adequately address the identified unsafe condition. The actions specified by the proposed AD are intended to detect and correct fatigue cracking, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage.
DATES: Comments must be received by December 9, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-192-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York.
FOR FURTHER INFORMATION CONTACT: George Duckett, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York 11581; telephone (516) 256-7525; fax (516) 568-2716.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-192-AD.'' The postcard will be date stamped and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-192-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On July 11, 1997, the FAA issued AD 97-14-11, amendment 39-10082 (62 FR 38206, July 17, 1997), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 200) series airplanes, to require repetitive inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations, and repair, if necessary. That action was prompted by a report of a pressurization problem during flight, which was caused by fatigue cracking in the underfloor pressure bulkhead of the fuselage. The requirements of that AD are intended to detect and correct such fatigue cracking, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage.
Actions Since Issuance of Previous Rule
In the preamble of AD 97-14-11, the FAA indicated that the actions required by that AD were considered ``interim action'' and that further rulemaking action was being considered to require modification of the affected fuselage frames once new service information was available. The manufacturer has now released such information, and the FAA has determined that further rulemaking is indeed necessary; this proposed AD follows from that determination.
Issuance of New Service Information
The manufacturer has issued Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997, which describes procedures for repetitive detailed inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations; and follow-on corrective actions, if necessary. The
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inspections also involve determining whether a crack located at the pressure bulkhead of frame station (FS)409+128 is within certain limits specified in the alert service bulletin.
In the event that a crack is determined to be outside the limits specified in Part A of the Accomplishment Instructions of the alert service bulletin, the follow-on corrective actions would include a high frequency eddy current (HFEC) inspection of the forward side of the web, to detect cracks of fuselage FS409+128 bulkhead web along the upper edge of the horizontal angle. As listed in Part A of paragraph 2.B. of the Accomplishment Instructions, airplanes may be returned to service provided that any cracking detected is within certain limits specified in the alert service bulletin.
The manufacturer also has issued Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997, which describes procedures for repair of the pressure bulkhead at FS409+128.
The manufacturer also has issued Canadair Regional Jet Service Bulletin 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997, describes procedures for modification of the affected areas of the pressure bulkhead at FS409+128. This modification is only applicable to those airplanes that have been inspected and are found to be free of cracks. The modification involves the installation of reinforcement components for the pressure bulkhead at FS409+128.
Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. Transport Canada Civil Aviation (TCCA) classified Canadair Regional Jet Service Bulletins A601R-53-045 and 601R-53-046 as mandatory, but did not classify Service Bulletin 601R-53-047 as mandatory, and issued Canadian airworthiness directive CF-97-11R2, dated December 22, 1997, in order to assure the continued airworthiness of these airplanes in Canada.
FAA's Conclusions
This airplane model is manufactured in Canada and is type certificated for operation in the United States under the provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, TCCA has kept the FAA informed of the situation described above. The FAA has examined the findings of TCCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would supersede AD 97-14-11 to continue to require repetitive inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations. This proposed AD would revise the repetitive inspection intervals for certain airplanes, and would require modification or repair, as applicable. Accomplishment of the modification or repair would terminate the requirements of this proposed AD. Certain actions would be required to be accomplished in accordance with the service bulletins described previously.
Operators should note that, while it is not the FAA's normal policy to allow flight with known cracks, this AD does permit further flight with cracking within certain limits. The results of a review, conducted by the manufacturer, revealed that cracking in the underfloor pressure bulkhead of the fuselage will not result in rapid decompression of the airplane. Therefore, according to the review, if the crack size limits are strictly observed and if repetitive inspections are performed at the required intervals, cracks that grow beyond the limits will be detected, and corrective action taken, before they can grow to a size that would create an unacceptable risk of structural failure. Transport Canada Civil Aviation concurs with the findings of this review. In consideration of these findings and based on the FAA's criteria for flight with known cracking, the FAA has determined that further flight with cracking within certain limits in the center pressure bulkhead is permissible for an interim period.
Differences Between Proposed Rule and Service Bulletin
Operators should note that the Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997, recommends that the initial inspection be performed no later than 10 flight hours after the alert service bulletin date of issuance. This proposed AD would increase the initial inspection threshold to require the initial inspection be performed within 20 flight hours after the effective date of this AD. In developing an appropriate initial inspection compliance time for this AD, the FAA considered not only the manufacturer's recommendation, but also the degree of urgency associated with addressing the subject unsafe condition. In light of these factors, the FAA finds a compliance time of 20 flight hours for initiating the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.
Operators also should note that, although the Canadair Regional Jet Service Bulletins A601R-53-045, Revision `D,' and 601R-53-046, Revision `B,' specify that the manufacturer may be contacted for disposition of certain cracking conditions, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA.
Differences Between Proposed Rule and Foreign Airworthiness Directive
The proposed AD would differ from the parallel Canadian airworthiness directive in that it would require accomplishment of the modification described in Canadair Regional Jet Service Bulletin 601R- 53-047, Revision `D,' within 9 months after the effective date of this AD. The parallel Canadian airworthiness directive recommends, but does not require, the accomplishment of the modification. Additionally, in the event that cracking within certain limits is found, this proposed AD would require a repair to be accomplished within 6 months after the effective date of this AD, or within 3 months after the initial date the crack was detected, whichever occurs later. The Canadian airworthiness directive specifies that the airplane may be returned to service provided that re-inspections are accomplished at certain flight hour intervals. The FAA has determined that, in this case long-term continued operational safety will be adequately assured by accomplishing the modification or repair to remove the source of the problem, rather than by accomplishing repetitive inspections at certain flight hour intervals.
Explanation of Applicability
The applicability of this proposed AD would affect Bombardier Model CL-600-2B19 (Regional Jet Series 100) series airplanes, whereas the previously issued AD 97-14-11 addressed Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 200) series airplanes. The FAA inadvertently referenced Bombardier Model CL-600-2B19 (Regional Jet Series 200) series
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airplanes in the previously issued AD. This airplane series is not type certificated in the U.S.
Additionally, the applicability of this proposed AD excludes any airplane on which Canadair Regional Jet Service Bulletins 601R-53-046, Revision `B,' dated December 22, 1997, and 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997, has been accomplished.
Cost Impact
There are approximately 77 airplanes of U.S. registry that would be affected by this proposed AD.
The inspection that is currently required by AD 97-14-11 takes approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required inspection on U.S. operators is estimated to be $9,960, or $120 per airplane, per inspection cycle.
The repair that is proposed in this AD action would take approximately 300 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $1,828. Based on these figures, the cost impact of the repair on U.S. operators is estimated to be $19,828 per airplane.
The modification that is proposed in this AD action would take approximately 212 hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $935. Based on these figures, the cost impact of the modification on U.S. operators is estimated to be $13,655 per airplane.
The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. However, the FAA has been advised that the manufacturer has committed previously to its customers that it will bear the labor costs associated with the repair and modification associated with accomplishing the actions required by this AD. Additionally, the manufacturer has indicated the warranty remedies may be available to defer the cost of the replacement parts also associated with accomplishing the actions required by this proposed AD.
Regulatory Impact
The regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that 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); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by removing amendment 39-10082 (62 FR 38206, July 17, 1997), and by adding a new airworthiness directive (AD), to read as follows:
Bombardier, Inc. (Formerly Canadair): Docket 98-NM-192-AD. Supersedes AD 97-14-11, Amendment 39-10082.
Applicability: Model CL-600-2B19 (Regional Jet Series 100) series airplanes, serial numbers 7003 through 7185 inclusive; except those airplanes on which Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997, or 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997, has been accomplished; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (d)(1) 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 detect and correct fatigue cracking in the underfloor pressure bulkhead of the fuselage, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage, accomplish the following:
Detailed Visual Inspections
(a) Perform a detailed visual inspection to detect cracks at FS409+128 of the bulkhead web drawing number 601R32208-123 of the fuselage, in accordance with Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, until accomplishment of paragraph (b) or (c) of this AD, as applicable.
(1) For airplanes that have accomplished a detailed visual inspection in accordance with AD 97-14-11 prior to the effective date of this AD: Perform a subsequent detailed visual inspection prior to the accumulation of 1,000 total flight hours, or within 100 flight hours after the immediately preceding inspection accomplished in accordance with AD 97-14-11, whichever occurs later. Thereafter, repeat the inspection at intervals not to exceed 100 flight hours.
(2) For airplanes that have not accomplished a detailed visual inspection in accordance with AD 97-14-11 prior to the effective date of this AD: Perform a detailed visual inspection within 20 flight hours after the effective date of this AD. Perform a subsequent detailed visual inspection prior to the accumulation of 1,000 total flight hours, or within 100 flight hours after accomplishment of the immediately preceding inspection, whichever occurs later. Thereafter, repeat the inspection at intervals not to exceed 100 flight hours.
Note 2: For the purposes of this AD, a detailed visual inspection is defined as: ``An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc. may be used. Surface cleaning and elaborate access procedures may be required.''
Note 3: Accomplishment of the inspection required by paragraph (a) of this AD, prior to the effective date of this AD in accordance with Canadair Regional Jet Alert Service Bulletin A601R-53-045, dated June 25, 1997; Revision `A,' including Appendix 1, dated June 26, 1997; Revision `B,' including Appendix 1, dated June 27, 1997; or Revision
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`C,' including Appendix 1, dated July 2, 1997; is considered acceptable for compliance with the applicable action specified by this AD.
Modification
(b) For any airplane on which no cracking has been detected during any inspection required by paragraph (a) of this AD: Within 9 months after the effective date of this AD, modify FS409+128 of the bulkhead web drawing number 601R32208-123 of the fuselage in accordance with Canadair Regional Jet Service Bulletin 601R-53-047, including Appendix 1, Revision `D,' dated December 22, 1997. Accomplishment of this modification terminates the requirements of this AD.
Note 4: Any modification accomplished prior to the effective date of this AD in accordance with Canadair Regional Jet Service Bulletin 601R-53-047, including Appendix 1 and Appendix 2, dated July 18, 1997; Revision `A,' including Appendix 1, dated July 31, 1997; Revision `B,' including Appendix 1, dated August 22, 1997; or Revision `C,' including Appendix 1, dated October 7, 1997; is considered acceptable for compliance with the applicable actions required by this AD.
Repair
(c) For any airplane on which any cracking is detected during any inspection required by paragraph (a) of this AD: Prior to further flight, determine the extent of the cracking as specified in Part A of paragraph 2.B. of the Accomplishment Instructions of Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997, and accomplish the requirements of paragraph (c)(1) or (c)(2), as applicable.
(1) If the cracking is within the limits specified by Part A of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, accomplish the requirements of paragraphs (c)(1)(i) and (c)(1)(ii) of this AD at the time specified in those paragraphs.
(i) Repeat the detailed visual inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 100 flight hours; and
(ii) Within 6 months after the effective date of this AD, or within 3 months after the initial date the crack was detected, whichever occurs later: Repair the affected area in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997. Accomplishment of this repair terminates the requirements of this AD.
Note 5: Any repair accomplished prior to the effective date of this AD in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, dated June 27, 1997, or Revision `A,' dated July 2, 1997, is considered acceptable for compliance with the applicable actions specified by this AD.
(2) If the cracking is outside the limits specified by Part A of the Accomplishment Instructions of the alert service bulletin, prior to further flight, perform a high frequency eddy current (HFEC) inspection to detect cracks of the forward side of the web of fuselage FS409+128 bulkhead web drawing number 601R32208-123, along the upper edge of the horizontal angle part number 601R32208-73, in accordance with Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin.
(i) If, during any HFEC inspection required by paragraph (c)(2) of this AD, any cracking is detected that is within the limits specified by Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, accomplish the requirements of paragraphs (c)(2)(i)(A) and (c)(2)(i)(B) of this AD at the times specified in those paragraphs.
(A) Repeat the HFEC inspection required by paragraph (c)(2) of this AD thereafter at intervals not to exceed 50 flight hours, and repeat the detailed visual inspection required by paragraph (a) of this AD thereafter at interval not to exceed 100 flight hours; and
(B) Within 6 months after the effective date of this AD, or within 3 months after the initial date the crack was detected, whichever occurs later: Repair the affected area in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997. Accomplishment of this repair terminates the requirements of this AD.
(ii) If, during any HFEC inspection required by paragraph (c)(2) of this AD, any cracking is detected that is outside the limits specified by Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, prior to further flight, determine the extent of the cracking as specified in paragraph 1.D. (``Compliance'') of Canadair Regional Jet Service Bulletin 601R-53- 046, Revision `B,' dated December 22, 1997, and accomplish the requirements of paragraph (c)(2)(ii)(A) or (c)(2)(ii)(B) of this AD, as applicable.
(A) If the cracking is within the limits specified by paragraph 1.D. (``Compliance'') of the service bulletin, prior to further flight, repair in accordance with the service bulletin. Accomplishment of this repair terminates the requirements of this AD.
(B) If the cracking is outside the limits specified by paragraph 1.D. (``Compliance'') of the service bulletin, prior to further flight, repair in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO).
Alternative Methods of Compliance
(d)(1) 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 ACO. 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.
(d)(2) Alternative methods of compliance, approved previously in accordance with AD 97-14-11, amendment 39-10082, are approved as alternative methods of compliance for this AD.
Note 6: 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 Permits
(e) Special flight permits may be issued in accordance with Secs. 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.
Note 7: The subject of this AD is addressed in Canadian airworthiness directive CF-97-11R2, dated December 22, 1997.
Issued in Renton, Washington, on November 2, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-29177Filed11-8-99; 8:45 am]
BILLING CODE 4910-13-U
