Airworthiness directives: Aerospatiale,
[Federal Register: October 25, 1999 (Volume 64, Number 205)]
[Proposed Rules]
[Page 57409-57413]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25oc99-16]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-94-AD]
RIN 2120-AA64
Airworthiness Directives; Aerospatiale Model ATR42-200, ATR42- 300, and ATR42-320 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 Aerospatiale Model ATR42-300 and ATR42-320 series airplanes, that currently requires inspections to determine the proper installation of rivets in certain key holes and to detect cracks in the area of the key holes where rivets are missing; and correction of discrepancies. This action would increase the compliance time for the existing requirements and expand the
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applicability of the existing AD to include additional airplanes. This action also would require various inspections of the subject area for discrepancies, and corrective actions, if necessary; and replacement of certain cargo door hinges with new hinges. For certain airplanes, this action would also require replacement of friction plates, stop fittings, and bolts with new parts. 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 fatigue cracks of the cargo door skin, certain frames, and entry door stop fittings and friction plates, which could result in reduced structural integrity of the airplane.
DATES: Comments must be received by November 24, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-94-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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. 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-94-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-94-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
On September 10, 1993, the FAA issued AD 93-18-04, amendment 39- 8689 (58 FR 53853, October 19, 1993), applicable to certain Aerospatiale Model ATR42-300 and ATR42-320 series airplanes, to require an inspection to determine the proper installation of rivets in the key holes of certain fuselage frames; an inspection to detect cracks in area of the key holes where rivets are missing; and correction of discrepancies. That action was prompted by the discovery of cracks around key holes on fuselage frames 25 and 27 where rivets were missing. The requirements of that AD are intended to prevent the loss of strength of the fuselage frames.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, advises that Aerospatiale has continued fatigue testing of Aerospatiale Model ATR42-300 and ATR42-320 series airplanes. The DGAC has determined that, in addition to fuselage frames 25 and 27 there are other areas that require inspection and modification, if applicable, to ensure that fatigue cracks do not progress undetected and reduce the structural integrity of the airplane. These additional areas of concern include cargo door fasteners and hinges; certain standard fuselage frames; forward entry door stops, door stop bolts, friction and plates; and upper corners. Additionally, the DGAC has determined that the subject area on certain Model ATR42-200 series airplanes, which were not affected by AD 93-18-04, is identical to that on the affected Model ATR42-300 and ATR42-320 series airplanes. Therefore, all of these airplanes may be subject to the unsafe condition and should have fuselage frames 25 and 27 inspected.
Explanation of Relevant Service Information
Aerospatiale has issued Service Bulletin ATR42-53-0070, Revision 2, dated March 22, 1993, which describes procedures for a general visual inspection to determine the proper installation of rivets in the key holes of certain fuselage frames; and corrective action, if necessary. The corrective actions involve performing an eddy current inspection to detect cracks in the area of the key holes where rivets are missing, and installing rivets in uncracked holes.
Aerospatiale has issued Service Bulletin ATR42-52-0058, Revision 1, dated March 1, 1995, which describes procedures for replacement of the hinges on the cargo compartment door and fuselage with new improved hinges. The replacement procedures include inspections for fastener type and tolerances, hole diameters, or cracking, and repair; as applicable.
Aerospatiale has issued Service Bulletin ATR42-53-0076, Revision 2, dated October 15, 1996, which describes procedures for a general visual inspection of certain fuselage frames for proper installation of rivets, and corrective action, if necessary. The corrective actions involve a general visual inspection for cracks in the tooling or key holes, and installation of rivets in uncracked holes.
Aerospatiale also has issued Service Bulletin ATR42-52-0052, Revision 1, dated March 2, 1993, which describes procedures for an eddy current inspection of forward entry door stop holes to detect cracking; a detailed visual inspection of forward entry door friction plates to detect wear; and corrective action, if necessary. The corrective action involves replacement of door stop fittings and friction plates with new parts.
Aerospatiale also has issued Service Bulletin ATR42-52-0059, dated February 16, 1995, which describes procedures for replacement of forward entry door friction plates, upper corner stop fittings, and bolts with parts of an improved design.
Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified these service bulletins as
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mandatory and issued French airworthiness directive 92-044-046(B)R2, dated November 5, 1997, in order to assure the continued airworthiness of these airplanes in France.
FAA's Conclusions
These airplane models are manufactured in France 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 DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, 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 93-18-04 to require accomplishment of the actions specified in the service bulletins described previously. The actions would be required to be accomplished in accordance with the service bulletins described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although certain service bulletins described previously specify that the manufacturer may be contacted for disposition of certain repair conditions, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this proposed AD, a repair approved by either the FAA or the DGAC would be acceptable for compliance with this proposed AD.
Cost Impact
There are approximately 106 airplanes of U.S. registry that would be affected by this proposed AD.
The general visual inspection of fuselage frames 25 and 27 that is proposed in this AD action would 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 this inspection proposed by this AD on U.S. operators is estimated to be $180 per airplane.
The cargo door hinge and skin replacement that is proposed in this AD action would take approximately 250 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $9,880 per airplane. Based on these figures, the cost impact of the door structure replacement proposed by this AD on U.S. operators is estimated to be $24,880 per airplane.
The general visual inspection of the key and tooling holes that is proposed in this AD action would take approximately 100 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on this figure, the cost impact of this inspection proposed by this AD on U.S. operators is estimated to be $6,000 per airplane.
The eddy current and detailed visual inspections of the forward entry door stop fitting and friction plate that are proposed in this AD action would take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on this figure, the cost impact of these inspections proposed by this AD on U.S. operators is estimated to be $120 per airplane.
The replacement of the forward entry door stop fitting, friction plate, and upper door corner that is proposed in this AD action would take approximately 50 work hours per airplane to accomplish. The manufacturer has committed previously to its customers that it will bear the cost of replacement parts. As a result, the cost of those parts is not attributable to this proposed AD. Based on this figure, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $3,000 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]
-
Section 39.13 is amended by removing amendment 39-8689 (58 FR 53853, October 19, 1993), and by adding a new airworthiness directive (AD), to read as follows:
Aerospatiale: Docket 98-NM-94-AD. Supersedes AD 93-18-04, Amendment 39-8689.
Applicability: All Model ATR42-200, ATR42-300, and ATR42-320 series airplanes, 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 (h) 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
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been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent fatigue cracks of the cargo door skin, certain frames, entry door stop fittings, or friction plates, which could result in reduced structural integrity of the airplane, accomplish the following:
Frame 25 and 27 Inspection
(a) For airplanes having serial numbers 005 through 016 inclusive, 018 through 030 inclusive, 032 through 036 inclusive, 038, 040, 042, 043, 048 through 062 inclusive, 064 through 090 inclusive, 092 through 094 inclusive, and 096 through 228 inclusive: Prior to the accumulation of 36,000 total flight cycles, or within 180 days after the effective date of this AD, whichever occurs later, conduct a general visual inspection of fuselage frames 25 and 27 to verify the proper installation of a rivet in each of the key holes, in accordance with Aerospatiale Service Bulletin ATR42-53- 0070, Revision 2, dated March 22, 1993.
Note 2: For the purposes of this AD, a general visual inspection is defined as ``A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being check.''
Note 3: Inspection of fuselage frames 25 and 27 accomplished prior to the effective date of this AD in accordance with Aerospatiale Service Bulletin ATR42-53-0070, dated June 10, 1991, or Revision 1, dated June 12, 1992, is considered acceptable for compliance with the requirements of paragraph (a) of this AD.
(1) If a rivet is installed in each of the key holes, no further action is required by this paragraph.
(2) If a rivet is not installed in each of the key holes, prior to further flight, perform an eddy current inspection of each open key hole to detect cracks, in accordance with the service bulletin.
(i) If no crack is found during the eddy current inspection, prior to further flight, install a rivet in the open key hole in accordance with the service bulletin. After such installation, no further action is required by this paragraph for that key hole.
(ii) If any crack is found during the eddy current inspection, prior to further flight, repair the crack in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, or the Direction Generale de l'Aviation Civile (DGAC) (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD.
Inspection and Modification of Cargo Door Structure
(b) For airplanes equipped with a cargo compartment door on which Aerospatiale Modification 3191 has not been accomplished: Prior to the accumulation of 27,000 total flight cycles, or within 180 days after the effective date of this AD, whichever occurs later, except as provided by paragraph (c) of this AD, replace the hinges on the cargo compartment door and fuselage (including inspections for fastener type and tolerances, hole diameters, or cracking, and repair; as applicable) with new improved hinges, in accordance with paragraph 2. of the Accomplishment Instructions of Aerospatiale Service Bulletin ATR42-52-0058, Revision 1, dated March 1, 1995.
(c) Where the instructions in Aerospatiale Service Bulletin ATR42-52-0058, Revision 1, dated March 1, 1995, specify that ATR is to be contacted for a repair, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, or the DGAC (or its delegated agent).
Frame Inspection
(d) For airplanes having serial numbers 003 through 208 inclusive: Prior to the accumulation of 36,000 total flight cycles, or within 180 days after the effective date of this AD, whichever occurs later, conduct a general visual inspection of the identified fuselage frames for proper installation of a rivet in each of the tooling and key holes, in accordance with Aerospatiale Service Bulletin ATR42-53-0076, Revision 2, dated October 15, 1996.
(1) If a rivet is installed in each of the tooling or key holes, no further action is required by this paragraph.
(2) If a rivet is not installed in each of the tooling and key holes, prior to further flight, perform a detailed visual inspection of each open tooling or key hole to detect cracks, in accordance with the service bulletin.
Note 4: 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.''
(i) If no crack is found during the detailed visual inspection required by paragraph (d)(2) of this AD, prior to further flight, install a rivet in the open hole in accordance with the service bulletin.
(ii) If any crack is found during the visual inspection required by paragraph (d)(2) of this AD, prior to further flight, repair the crack in accordance with a method approved by the Manager, International Branch, ANM-116, or the DGAC (or its delegated agent).
Inspection and/or Replacement of Entry Door Structure
(e) For Model ATR42-300 series airplanes having serial numbers listed in Aerospatiale Service Bulletin ATR42-52-0052, Revision 1, dated March 2, 1993: Except as provided by paragraph (f) of this AD, prior to the accumulation of 10,000 total flight cycles, or within 90 days after the effective date of this AD, whichever occurs later, accomplish the requirements of paragraphs (e)(1) and (e)(2) of this AD.
(1) Perform an eddy current inspection of the forward entry door stop holes to detect cracking, in accordance with the service bulletin. If any cracking is detected, prior to further flight, replace any cracked forward entry door stop fitting with a new fitting, in accordance with the service bulletin.
(2) Perform a detailed visual inspection of the forward entry door friction plates for wear, in accordance with the service bulletin. If wear is found on any friction plate, and the wear has a depth equal to or greater than 0.8mm (0.0315 in.), prior to further flight, replace the friction plate with a new or serviceable part in accordance with the service bulletin.
(f) For Model ATR42-300 series airplanes listed in Aerospatiale Service Bulletin ATR42-52-0052, Revision 1, dated March 2, 1993, accomplishment of the requirements of paragraph (g) of this AD at the time specified in paragraph (e) of this AD constitutes terminating action for the requirements of paragraph (e) of this AD.
(g) For Model ATR42-300 series airplanes listed in Aerospatiale Service Bulletin ATR42-52-0059, dated February 16, 1995: Prior to the accumulation of 18,000 total flight cycles, or within 180 days after the effective date of this AD, whichever occurs later, accomplish the requirements of paragraphs (g)(1), (g)(2), and (g)(3) of this AD in accordance with the service bulletin.
(1) Replace the forward entry door friction plates with improved friction plates.
(2) Replace the upper corners of the forward entry door surround structure with improved door surround corners.
(3) Replace the forward entry door stop fittings and bolts with improved fittings and bolts.
Alternative Methods of Compliance
(h) 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 5: 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
(i) 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 6: The subject of this AD is addressed in French airworthiness directive 92-044-046(B)R2, dated November 5, 1997.
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Issued in Renton, Washington, on October 19, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-27792Filed10-22-99; 8:45 am]
BILLING CODE 4910-13-P
