Airworthiness directives: British Aerospace,
[Federal Register: January 5, 1999 (Volume 64, Number 2)]
[Proposed Rules]
[Page 435-438]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05ja99-22]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-47-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Model BAC 1-11 200 and 400 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 British Aerospace Model BAC 1-11 200 and 400 series airplanes. That AD currently limits the number of operations at increased cabin pressure differential, and requires repetitive structural inspections for cracking of the fuselage, and repair or replacement of parts, if necessary. This action would require additional repetitive inspections for cracking of the fuselage. This proposal is prompted by the determination that airplanes operating at increased cabin pressure differential are more likely to develop fatigue cracking earlier in their service lives than those airplanes operating at normal cabin differential pressures. The actions specified by the proposed AD are intended to detect and correct fatigue cracking of the airplane fuselage, which could result in reduced structural integrity of the airplane.
DATES: Comments must be received by February 4, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-47-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 British Aerospace, Service Support, Airbus Limited, P.O. Box 77, Bristol BS99 7AR, England. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.
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-47-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-47-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On August 14, 1989, the FAA issued AD 89-18-10, amendment 39-6310 (54 FR 34768, August 22, 1989), applicable to certain British Aerospace Model BAC 1-11 200 and 400 series airplanes. That AD currently limits the number of operations at increased cabin pressure differential, and requires repetitive structural inspections for cracking of the fuselage, and repair or replacement of parts, if necessary. That action was prompted by the determination that airplanes operating at increased cabin pressure differential are more likely to develop fatigue cracking earlier in their service lives than those airplanes operating at normal cabin differential pressures. The requirements of that AD are intended to prevent inability of the
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airplane structure to carry required loads.
Actions Since Issuance of AD 89-18-10
Since the issuance of AD 89-18-10, the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, advises that it has reviewed existing mandated supplemental fatigue inspections applied to older Model BAC 1-11 series airplanes. Following this review, additional routine visual inspections of the fuselage were recommended to improve the probability of the detection of fatigue cracking. Such fatigue cracking, if not corrected, could result in reduced structural integrity of the airplane.
Explanation of Relevant Service Information
The manufacturer has issued British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995, which describes procedures for repetitive structural inspections for cracking of the fuselage. The procedures described in Issue 2 of the service bulletin are essentially identical to Issue 1, however, it adds additional areas to be inspected and revises certain inspection thresholds and intervals. The CAA classified this alert service bulletin as mandatory in order to assure the continued airworthiness of these airplanes in the United Kingdom.
FAA's Conclusions
This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, 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 89-18-10 to continue to limit the number of operations at increased cabin pressure differential, and require repetitive structural inspections for cracking of the fuselage, and repair or replacement of parts, if necessary. The proposed AD would require additional repetitive structural inspections for cracking of the fuselage, revise certain inspection thresholds and intervals, and corrective actions, if necessary. The actions would be required to be accomplished in accordance with Issue 2 of the alert service bulletin described previously, except as discussed below.
Differences Between Proposed Rule and Alert Service Bulletin
Operators should note that, although the alert service bulletin does not specify an initial compliance time for performing the additional visual inspections, the FAA has determined that a threshold of 3 months to accomplish those inspections would address the identified unsafe condition in a timely manner. In developing this compliance time, the FAA considered the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspections. In light of all of these factors, the FAA finds that this compliance time represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.
Cost Impact
There are approximately 42 airplanes of U.S. registry that would be affected by this proposed AD.
The actions that are currently required by AD 89-18-10, and retained in this proposed AD, take approximately 67 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 actions on U.S. operators is estimated to be $168,840, or $4,020, per airplane.
The new inspections that are proposed in this AD action would take approximately 29 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 new proposed requirements of this AD on U.S. operators is estimated to be $73,080, or $1,740 per airplane, per inspection cycle.
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.
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: 49U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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Section 39.13 is amended by removing amendment 39-6310 (54 FR 34768, August 22, 1989), and by adding a new airworthiness directive (AD), to read as follows:
British Aerospace Airbus Limited (Formerly British Aerospace Commercial Aircraft Limited, British Aerospace Aircraft Group): Docket 98-NM-47-AD. Supersedes AD 89-18-10, Amendment 39-6310.
Applicability: Model BAC 1-11 200 and 400 series airplanes on which British Aerospace Modifications PM2840 and PM3187 have been accomplished; or on which British Aerospace Modification PM4886 has been accomplished; except for airplanes on which British Aerospace
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Modification PM5282 (cabin freight door) has been accomplished; and 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 (f) 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 of the airplane fuselage, which could result in reduced structural integrity of the airplane, accomplish the following:
(a) Except as provided by paragraph (c) of this AD: For airplanes modified for operation to a maximum of 7.75 pounds per square inch (psi) cabin pressure differential, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 27, 1987, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD.
(1) At or prior to the accumulation of 55,000 total landings, or within 15 months after September 28, 1989 (the effective date of AD 89-18-10, amendment 39-6310), whichever occurs later, perform the inspections specified in paragraph 2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.1.1 of the alert service bulletin at intervals shown in Table AA of the alert service bulletin.
(2) At or prior to the accumulation of 60,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, reduce the aircraft maximum cabin pressure differential to 7.5 psi by system modification, in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.
(b) Except as provided by paragraph (d) of this AD: For airplanes modified for operation at cabin pressure differentials above 7.75 psi up to a maximum of 8.2 psi, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 27, 1987, accomplish the requirements of paragraph (b)(1) or (b)(2) of this AD, as applicable. Subsequently, accomplish the requirements of paragraphs (b)(3) and (b)(4), or paragraphs (b)(5) and (b)(6) of this AD, as applicable.
(1) For airplanes originally manufactured for operation at cabin pressure differentials above 7.75 psi, at or prior to the accumulation of the number of landings shown for initial inspection in the ``NE period'' column of Table AA in the alert service bulletin, or within 15 months after September 28, 1989, whichever occurs later, perform inspections specified in paragraph 2.2.1 of the alert service bulletin and repeat the inspections as specified in paragraph 2.2.3 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin.
(2) For airplanes modified for operation at cabin pressure differential above 7.75 psi after the airplane entered service, at or prior to the accumulation of the number of landings shown for initial inspection in the ``NE period'' column [obtained using the inspection adjustment graph (page 6) of the alert service bulletin], in Table AA of the alert service bulletin, or within 15 months after September 28, 1989, whichever occurs later, perform initial inspections specified in paragraph 2.2.2 of the alert service bulletin. Thereafter, repeat the inspections as specified in paragraph 2.2.3 of the alert service bulletin, at intervals shown in Table AA of the alert service bulletin.
(3) At or prior to the accumulation of 55,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, reduce the aircraft cabin maximum operating pressure differential to 7.5 or 7.75 psi by modification as specified in paragraph 2.2.4 of the alert service bulletin, in accordance with a method approved by the Manager, International Branch, ANM-116.
(4) For airplanes which have had the cabin pressure differential reduced from 8.2 psi to 7.75 psi as specified in paragraph 2.2.6 of the alert service bulletin, perform repetitive inspections at the intervals specified in the ``N.E. period'' column in Table AA of the alert service bulletin.
(5) At or prior to the accumulation of 60,000 total landings, or within 30 days after September 28, 1989, whichever occurs later, the airplane cabin maximum operating pressure differential must be reduced to 7.5 psi by modification as specified in paragraph 2.2.7 of the alert service bulletin, in accordance with a method approved by the Manager, International Branch, ANM-116.
(6) For airplanes modified for 8.2 psi maximum cabin operating pressure differential and operated for a period in excess of any Table AA inspection threshold in the alert service bulletin, perform one additional inspection at or prior to the Table AA ``N.E. period'' column repeat interval after limiting operation to 7.5 psi, as specified in paragraph 2.2.5 of the alert service bulletin.
(c) For airplanes modified for operation to a maximum of 7.75 pounds per square inch (psi) cabin pressure differential, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995: Prior to the accumulation of the number of landings specified in Table AA of the alert service bulletin, or within 3 months after the effective date of this AD, whichever occurs later, perform the inspections specified in paragraph 2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.1.1 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin. Accomplishment of the inspections required by this paragraph terminates the repetitive inspections required by paragraph (a)(1) of this AD.
Note 2: Paragraph (a)(1) of this AD restates the requirement for an initial and repetitive inspections contained in paragraph A.1. of AD 89-18-10. Therefore, for operators who have previously accomplished at least the initial inspection in accordance with AD 89-18-10, paragraph (c) of this AD requires that the next scheduled inspection be performed within the repetitive inspection interval specified in Table AA of Issue 2 of the alert service bulletin, after the last inspection performed in accordance with paragraph A.1. of AD 89-18-10.
(d) For airplanes modified for operation at cabin pressure differentials above 7.75 psi up to a maximum of 8.2 psi, as specified in British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995: Prior to the accumulation of the number of landings specified in Table AA of the alert service bulletin, or within 3 months after the effective date of this AD, whichever occurs later, perform the inspections specified in paragraph 2.2.1 of the alert service bulletin. Thereafter, repeat the inspections in accordance with paragraph 2.2.3 of the alert service bulletin at the intervals shown in Table AA of the alert service bulletin. Accomplishment of the inspections required by this paragraph terminates the repetitive inspections required by paragraph (b)(1), (b)(2) or (b)(4) of this AD, as applicable.
Note 3: Paragraph (b)(1) of this AD restates the requirement for an initial and repetitive inspections contained in paragraph B.1. of AD 89-18-10. Therefore, for operators who have previously accomplished at least the initial inspection in accordance with AD 89-18-10, paragraph (d) of this AD requires that the next scheduled inspection be performed within the repetitive inspection interval specified in Table AA of Issue 2 of the alert service bulletin, after the last inspection performed in accordance with paragraph B.1. of AD 89-18-10.
(e) If any defect is found during any inspection required by this AD, prior to further flight, accomplish paragraph (e)(1), (e)(2), or (e)(3) of this AD, as applicable.
(1) Replace the defective part with a serviceable part of the same part number in accordance with the Structural Repair Manual; or
(2) For damage within the limits specified in the BAC 1-11 Structural Repair Manual, repair in accordance with the Structural Repair Manual; or
(3) Repair in accordance with a method approved by the Manager, International Branch, ANM-116.
(f) 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, International Branch, ANM-116. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.
Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.
(g) 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
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a location where the requirements of this AD can be accomplished.
Issued in Renton, Washington, on December 28, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-49Filed1-4-99; 8:45 am]
BILLING CODE 4910-13-P
