Airworthiness directives: British Aerospace,
[Federal Register: October 27, 1998 (Volume 63, Number 207)]
[Proposed Rules]
[Page 57266-57268]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27oc98-25]
[[Page 57266]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-195-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 cracks in the shear cleats of the roller guide structural support of the passenger door, and replacement of any cracked shear cleat with a new shear cleat. That AD also provides for an optional terminating modification that constitutes terminating action for the repetitive inspections. This action would mandate accomplishment of the previously optional terminating modification. This proposal is prompted by reports indicating that fatigue cracking was detected in the roller guide shear cleats of the passenger door. The actions specified by the proposed AD are intended to prevent such fatigue-related cracking, which could result in structural failure or loss of the passenger door, and consequent rapid depressurization of the airplane during flight.
DATES: Comments must be received by November 27, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-N-195-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-195-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-195-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On July 21, 1997, the FAA issued AD 97-16-01, amendment 39-10090 (62 FR 40267, July 28, 1997), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, to require repetitive detailed visual inspections to detect cracks in the shear cleats of the roller guide structural support of the passenger door, and replacement of any cracked shear cleat with a new shear cleat. That AD also provides for an optional modification that constitutes terminating action for the repetitive inspections. That action was prompted by a report indicating that fatigue cracking was found in the roller guide shear cleats of the passenger door. The requirements of that AD are intended to detect and correct such fatigue-related cracking, which could result in structural failure of the passenger door, and consequent rapid depressurization of the airplane or loss of the passenger door while the airplane is in flight.
Actions Since Issuance of Previous Rule
When AD 97-16-01 was issued, it contained a provision for an optional modification of the passenger door which, if accomplished, would constitute terminating action for the required repetitive inspections. Also, in AD 97-16-01, the FAA indicated that the inspections required by that AD were considered ``interim action'' and that it was considering further rulemaking action to mandate accomplishment of the terminating modification. This action proposes such a requirement, to be accomplished in accordance with Jetstream Service Bulletin J41-52-050, dated May 6, 1997. (This service bulletin was described previously in AD 97-16-01.)
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 Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, 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 indeed 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 97-16-01 to continue to require repetitive detailed visual inspections to detect cracks in the shear cleats of the roller guide structural support of the passenger door, and replacement of any cracked shear cleat with a new shear cleat. In addition, the proposed AD would mandate accomplishment of the previously optional terminating modification.
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Differences Between Proposed Rule and Service Bulletin
Operators should note that this AD proposes to mandate the modification of the passenger door described in Jetstream Service Bulletin J41-52-050 as terminating action for the repetitive inspections. Incorporation of this terminating action was classified as optional in this service bulletin.
The FAA has determined that long-term continued operational safety will be better assured by design changes to remove the source of the problem, rather than by repetitive inspections. Long-term inspections may not be providing the degree of safety assurance necessary for the transport airplane fleet. This, coupled with a better understanding of the human factors associated with numerous continual inspections, has led the FAA to consider placing less emphasis on inspections and more emphasis on design improvements. The proposed modification requirement is in consonance with these conditions.
Cost Impact
There are approximately 57 airplanes of U.S. registry that would be affected by this proposed AD.
The inspections that are currently required by AD 97-16-01, and retained in this proposed AD, take approximately 3 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 inspections on U.S. operators is estimated to be $10,260, or $180 per airplane, per inspection cycle.
The new modification that is proposed by this AD action would take approximately 55 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $2,460 per airplane. Based on these figures, the cost impact of the modification proposed by this AD on U.S. operators is estimated to be $328,320, or $5,760 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.
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]
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Section 39.13 is amended by removing amendment 39-10090 (62 FR 40267, July 28, 1997), 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 97-NM-195-AD. Supersedes AD 97-16-01, Amendment 39-10090.
Applicability: Jetstream Model 4101 airplanes, constructor's numbers 41004 through 41099 inclusive; 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 (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 prevent fatigue-related cracking in the shear cleats of the roller guide structural support of the passenger door, which could result in structural failure or loss of the passenger door, and consequent rapid depressurization of the airplane during flight, accomplish the following:
Restatement of Reqirements of AD 97-16-01
(a) Except as provided by paragraph (b) of this AD: Prior to the accumulation of 6,000 landings, or within 60 days after August 12, 1997 (the effective date of AD 97-16-01, amendment 39-10090), whichever occurs later, perform a detailed visual inspection to detect cracks of the shear cleats of the roller guide structural support of the passenger door, in accordance with Part 1 of the Accomplishment Instructions of Jetstream Alert Service Bulletin J41- A52-043, Revision 2, dated May 6, 1997. Repeat the detailed visual inspection, as specified in Part 2 of the Accomplishment Instructions of the alert service bulletin, thereafter at intervals not to exceed 1,500 landings.
Note 2: Accomplishment of the initial detailed visual inspection prior to August 12, 1997, in accordance with Jetstream Alert Service Bulletin J41-52-043, dated March 14, 1997, or Revision 1, dated April 11, 1997, is considered acceptable for compliance with the initial inspection required by paragraph (a) of this AD.
(1) If one cracked shear cleat is detected, and the crack is greater than 0.50 inches, prior to further flight, replace the cracked shear cleat with a new shear cleat in accordance with the alert service bulletin.
(2) If one cracked shear cleat is detected, and the crack is less than or equal to 0.50 inches, within 170 landings following accomplishment of the inspection required by this paragraph, replace the cracked shear cleat with a new shear cleat in accordance with the alert service bulletin.
(3) If more than one cracked shear cleat is detected, but no single crack is greater than 0.50 inches in length, prior to further flight, replace all cracked shear cleats with new shear cleats in accordance with the alert service bulletin.
(b) For airplanes on which all shear cleats have been replaced: Inspect as required by paragraph (a) of this AD, prior to the accumulation of 6,000 total landings on the highest time new shear cleat, or within 60 days after August 12, 1997, whichever occurs later. Repeat the detailed visual inspection thereafter at intervals not to exceed 1,500 landings.
New Requirements of this AD
(c) Modify the passenger door (Modification No. JM41576) at all four roller guide locations in accordance with Jetstream Service Bulletin J41-52-050, dated May 6, 1997, at the time specified in paragraph (c)(1) or (c)(2) of this AD, whichever occurs later. Accomplishment of this modification
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constitutes terminating action for the requirements of this AD.
(1) Within 4,000 landings or 2 years after accomplishment of the initial inspection required by paragraph (a) of this AD. Or
(2) Within 6 months after the effective date of this AD.
(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.
(e) 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.
Issued in Renton, Washington, on October 21, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-28665Filed10-26-98; 8:45 am]
BILLING CODE 4910-13-P
