Airworthiness directives: British Aerospace,
[Federal Register: September 8, 1998 (Volume 63, Number 173)]
[Proposed Rules]
[Page 47445-47447]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08se98-21]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-129-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Model BAe 146 and Model Avro 146-RJ Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain British Aerospace Model BAe 146 and Model Avro 146-RJ series airplanes. This proposal would require a one-time measurement to determine the thickness of the outer links of the side stays of the main landing gear (MLG), and corrective actions, if necessary. This proposal also would provide for replacement of a thin outer link with a new or serviceable part in lieu of certain follow-on inspections. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent cracking of the outer links of the side stays of the MLG, which could result in increased braking distance during landing, and consequent runway overrun.
DATES: Comments must be received by October 8, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-129-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 AI(R) American Support , Inc., 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 97-NM-129-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. 97-NM-129-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on certain British Aerospace Model BAe 146 and Model Avro 146-RJ series airplanes. The CAA advises that it has received a report of cracking on the shoulder of two outer links of a side stay of the main landing gear (MLG). Investigation has revealed that the insufficient thickness of the outer links on certain Model BAe 146 and Model Avro 146-RJ series airplanes causes them to be susceptible to this type of cracking. In addition, this cracking may have been aggravated by insufficient greasing of the spherical bearing, which could result in increased stress on the side stay when the gear is in transit. Such cracking, if not corrected, could result in increased braking distance during landing, and consequent runway overrun.
Explanation of Relevant Service Information
The manufacturer has issued British Aerospace Service Bulletin SB.32-144, dated December 11, 1996, which describes procedures for a one-time measurement to determine the thickness of the outer links of the side stays of the MLG. The measurement involves placing a profile gauge over the thinnest section of the outer link profile. For outer links on which a profile gauge slips over the profile, the service bulletin also describes procedures for follow-on repetitive detailed visual inspections to detect cracking of the outer links, and replacement of any cracked outer link with a new or serviceable part.
The British Aerospace service bulletin references Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996, as an additional source of service information for accomplishment of the measurement.
Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The CAA approved Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996; classified British Aerospace Service Bulletin SB.32-144, dated December 11, 1996, as mandatory; and issued British airworthiness directive 005-12-96 in order to assure the continued airworthiness of these airplanes in the United Kingdom.
FAA's Conclusions
These airplane models are manufactured in the United Kingdom and are 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
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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 require accomplishment of the actions specified in the British Aerospace service bulletin described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, unlike the procedures described in Messier-Dowty Service Bulletin 146-32-128 and British Aerospace Service Bulletin SB.32-144, this proposed AD would not permit further flight if cracks are detected in the outer links of the side stays of the MLG. The FAA has determined that, because of the safety implications and consequences associated with such cracking, any subject outer link that is found to be cracked must be replaced prior to further flight.
In addition, operators should note that, for airplanes on which the profile gauge slips over the top edge of the outer link profile, the service bulletins do not describe a terminating action for the follow- on repetitive inspections to detect cracking of the outer links. However, this proposed AD would allow replacement of a thin outer link with a new or serviceable part in lieu of the follow-on inspections.
Cost Impact
The FAA estimates that 37 airplanes of U.S. registry would be affected by this proposed AD. It would take approximately 1 work hour per airplane to accomplish the proposed measurement, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to operators. Based on this figure, the cost impact of the measurement proposed by this AD on U.S. operators is estimated to be $2,220, or $60 per airplane.
The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the 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 adding the following new airworthiness directive: British Aerospace Regional Aircraft (Formerly British Aerospace Regional Aircraft Limited, Avro International Aerospace Division; British Aerospace, PLC; British Aerospace Commercial Aircraft Limited): Docket 97-NM-129-AD.
Applicability: Model BAe 146 and Model Avro 146-RJ series airplanes, equipped with side stays of the main landing gear (MLG) having part numbers (P/N) listed in Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996; certificated in any category.
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 (c) 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 cracking of the outer links of the side stays of the main landing gear (MLG), which could result in increased braking distance during landing, and consequent runway overrun, accomplish the following:
(a) Within 500 landings or 60 days after the effective date of this AD, whichever occurs later, perform a one-time measurement to determine the thickness of the outer links of the side stays of the MLG, in accordance with British Aerospace Service Bulletin SB.32- 144, dated December 11, 1996.
Note 2: The British Aerospace service bulletin references Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996, as an additional source of service information for accomplishment of the measurement.
(1) If the profile gauge does not slip over the top edge of the outer link profile, no further action is required by this AD.
(2) If the profile gauge slips over the top edge of the outer link profile, prior to further flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this AD.
(i) Replace the outer link with a new or serviceable part in accordance with the service bulletin. After replacement of the outer link, no further action is required by this AD.
Note 3: For purposes of this AD, a ``serviceable'' outer link is defined as an outer link that is not cracked and on which a profile gauge does not slip over the top edge of the profile, as described in the service bulletin.
(ii) Perform a detailed visual inspection to detect cracking of the outer links of the side stays of the MLG, in accordance with the service bulletin.
(A) If no cracking is detected, repeat the detailed visual inspection thereafter at intervals not to exceed 4,000 landings.
(B) If any cracking is detected during any detailed visual inspection required by this AD, prior to further flight, replace the cracked outer link with a new or serviceable part in accordance with the service bulletin. After replacement of the outer link, no further action is required by this AD.
(b) As of the effective date of this AD, no person shall install on any airplane a side stay of the MLG having a part number listed in paragraph 1.A. of Messier-Dowty Service Bulletin 146-32-128, dated December 6, 1996; unless the profile gauge does not slip over the profile of the outer links of the side stay, as described in British Aerospace Service Bulletin SB.32-144, dated December 11, 1996.
(c) An alternative method of compliance or adjustment of the compliance time that
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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 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.
(d) 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.
Note 5: The subject of this AD is addressed in British airworthiness directive 005-12-96.
Issued in Renton, Washington, on September 1, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-24060Filed9-4-98; 8:45 am]
BILLING CODE 4910-13-P
