Airworthiness directives: British Aerospace,
[Federal Register: November 26, 1999 (Volume 64, Number 227)]
[Proposed Rules]
[Page 66424-66426]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26no99-29]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-306-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace (Jetstream) Model 4101 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 (Jetstream) Model 4101 airplanes, that currently requires repetitive detailed visual inspections to detect cracking or other damage of certain diaphragm support structures of the forward equipment compartment; and repair, if necessary. This action would continue to require repetitive inspections, but would also require replacement of cracked or damaged diaphragm support structures with improved parts, which would terminate the requirement for repetitive inspections. This action also would add airplanes to the applicability of the proposed AD. This proposal is prompted by the development of improved diaphragms. The actions specified by the proposed AD are intended to prevent failure of the two diaphragms that support the upper structure of the forward equipment compartment, which could accelerate fatigue damage in adjacent structure and result in reduced structural integrity of the airframe.
DATES: Comments must be received by December 27, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-306-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 Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. 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 99-NM-306-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. 99-NM-306-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On November 9, 1998, the FAA issued AD 98-24-01, amendment 39-10888 (63 FR 63975, November 18, 1998), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, to require repetitive detailed visual inspections to detect cracking or other damage of certain diaphragm support structures of the forward equipment compartment; and repair, if necessary. That action was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The requirements of that AD are intended to detect and correct failure of the two diaphragms that support the upper structure of the forward equipment compartment, which could accelerate fatigue damage in adjacent structure and result in reduced structural integrity of the airframe.
In the preamble to AD 98-24-01, the FAA indicated that the actions required by that AD were considered ``interim action'' and that further rulemaking action was being considered. The FAA now has determined that further rulemaking action is indeed necessary, and this proposed AD follows from that determination.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the manufacturer has issued new service information that specifies procedures for replacement of both diaphragms with improved diaphragms if any cracking or damage is found. The replacement would eliminate the need for the repetitive inspections.
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The new service information also expands the applicability to include additional airplanes. This proposal would modify the applicability to include only those airplanes on which modification of the diaphragm support structure has not been accomplished. Reference to constructors numbers has been removed from the applicability of this proposed AD.
Explanation of Relevant Service Information
British Aerospace has issued Jetstream Alert Service Bulletin J41- A53-023, Revision 1, dated July 30, 1999, which describes procedures for replacement of cracked or damaged diaphragm support structures with improved parts, in addition to the repetitive inspections described in the original release of the service bulletin. This replacement would eliminate the need for further repetitive inspections. Accomplishment of the actions specified in Revision 1 of the service bulletin is intended to adequately address the identified unsafe condition. The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, classified this 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 Sec. 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 98-24-01 to continue to require the actions specified in that AD. This proposed AD would also require accomplishment of the actions specified in Revision 1 of the service bulletin described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, unlike the procedures described in Jetstream Alert Service Bulletin J41-A53-023, Revision 1, dated July 30, 1999, this proposed AD would not permit further flight if cracks are detected in certain diaphragms that support the upper structure of the forward equipment compartment. The FAA has determined that, because of the safety implications and consequences associated with such cracking, any subject diaphragm that is found to be cracked must be replaced with new, improved parts prior to further flight.
Cost Impact
There are approximately 59 airplanes of U.S. registry that would be affected by this proposed AD.
The inspection that is currently required by AD 98-24-01, and retained in this proposed AD, takes approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection requirement of this proposed AD on U.S. operators is estimated to be $3,540, or $60 per airplane, per inspection cycle.
The cost impact figure discussed above is 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: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by removing amendment 39-10888 (63 FR 63975, November 18, 1998), and by adding a new airworthiness directive (AD), to read as follows:
British Aerospace Regional Aircraft [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Docket 99-NM-306-AD. Supersedes AD 98-24-01, Amendment 39-10888.
Applicability: Jetstream Model 4101 airplanes, on which British Aerospace Modification JM41384 has not 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) 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 failure of the two diaphragms that support the upper structure of the forward equipment compartment, which could accelerate fatigue damage in adjacent structure and result in reduced structural integrity of the airframe, accomplish the following:
Restatement of Certain Requirements of AD 98-24-01
(a) For airplanes having constructors numbers 41004 through 41098 inclusive: Prior to the accumulation of 4,500 total landings, or within 300 landings after December 23, 1998 (the effective date of AD
[[Page 66426]]
98-24-01, amendment 39-10888), whichever occurs later: Perform a detailed visual inspection to detect cracking or other damage of the diaphragms installed between station 4 and station 8 of the forward fuselage, in accordance with Jetstream Alert Service Bulletin J41- A53-023, dated December 2, 1996, or Revision 1, dated July 30, 1999.
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.''
(1) If no cracking or other damage is detected, repeat the inspection thereafter at intervals not to exceed 3,000 landings.
(2) If any cracking or other damage is detected, prior to further flight, accomplish the actions required by either paragraph (a)(2)(i) or (a)(2)(ii). After the effective date of this AD, only replacement of the diaphragms in accordance with paragraph (a)(2)(ii) of this AD is acceptable for compliance with the repair requirements of this paragraph.
(i) Repair the diaphragm in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Thereafter, repeat the inspection at intervals not to exceed 3,000 landings.
(ii) Replace both diaphragms with new, improved diaphragms, in accordance with Part 2 of the Accomplishment Instructions of Jetstream Alert Service Bulletin J41-A53-023, Revision 1, dated July 30, 1999. Such replacement constitutes terminating action for the repetitive inspections required by this AD.
New Repetitive Inspections and Corrective Actions Required by This AD:
(b) For airplanes other than those listed in paragraph (a) of this AD: Prior to the accumulation of 4,500 total landings, or within 300 landings after the effective date of this AD, whichever occurs later, perform a detailed visual inspection to detect cracking or other damage of the diaphragms installed between station 4 and station 8 of the forward fuselage, in accordance with Jetstream Alert Service Bulletin J41-A53-023, Revision 1, dated July 30, 1999.
(1) If no cracking or other damage is detected, repeat the inspection thereafter at intervals not to exceed 3,000 landings.
(2) If any cracking or other damage is detected, prior to further flight, replace both diaphragms with new, improved diaphragms, in accordance with Part 2 of the Accomplishment Instructions of Jetstream Alert Service Bulletin J41-A53-023, Revision 1, dated July 30, 1999. Such replacement constitutes terminating action for the repetitive inspections required by this AD.
(c) Replacement of diaphragms with new, improved diaphragms, in accordance with Part 2 of the Accomplishment Instructions of Jetstream Alert Service Bulletin J41-A53-023, Revision 1, dated July 30, 1999, constitutes terminating action for the requirements of this AD.
Alternative Methods of Compliance
(d) 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, FAA, Transport Airplane Directorate. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.
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.
Issued in Renton, Washington, on November 19, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-30799Filed11-24-99; 8:45 am]
BILLING CODE 4910-13-P
