Airworthiness directives: Airbus,
[Federal Register: April 28, 1999 (Volume 64, Number 81)]
[Proposed Rules]
[Page 22816-22818]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28ap99-16]
Proposed Rules Federal Register
This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules.
[[Page 22816]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-17-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A310 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 Airbus Model A310 series airplanes. This proposal would require repetitive inspections to detect cracked or broken support brackets of the upper wing-to-fuselage fairings, and replacement of any discrepant support brackets with new brackets. This proposal also would require replacement of the fairing seals with new, improved seals; modification of the fairing panels; and installation of new bulkheads; which would constitute terminating action for the repetitive 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 reduced structural integrity of the fairing support brackets, which could result in loss of the wing-to-fuselage fairings during flight, and consequent structural damage to the airplane.
DATES: Comments must be received by May 28, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-17-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 Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, 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 99-NM-17-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-17-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
Discussion
The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A310 series airplanes.
The DGAC advises that it has received several reports of loss of the upper wing-to-fuselage fairings during flight. The loss of these fairings is attributed to cracked or broken support brackets that attach the three wing-to-fuselage fairings located between fuselage frame (FR) 40 and FR54.2. Investigation revealed that the cracking of the support brackets occurred because of bending of the forward and aft panels caused by a lack of stiffness along the lower edge of the panels, due to a step in the center fairing panel at FR47.
To prevent such discrepancies, a new center fairing panel with no step, together with new support brackets (in a location closer to the upper edge of the panel), was installed on certain other Airbus Model A310 series airplanes. Subsequently, additional reports were received of cracked or broken support brackets, again resulting in loss of the wing-to-fuselage fairings during flight. Further investigation revealed the ultimate cause of the loss of the fairings to be vibration induced by ram air penetrating between the fairing and the fuselage, which caused the aft fairing support brackets to break. Such conditions, if not detected and corrected, could result in loss of the wing-to- fuselage fairings during flight, and consequent structural damage to the airplane.
Explanation of Relevant Service Information
The manufacturer has issued Airbus Service Bulletin A310-53-2078, Revision 1, dated March 24, 1997, which describes procedures for repetitive inspections to detect cracked or broken support brackets of the upper wing-to-fuselage fairing, and replacement of any discrepant support brackets with new brackets.
The manufacturer also has issued Airbus Service Bulletin A310-53- 2083, Revision 02, dated May 5, 1998, which describes procedures for replacement of the fairing seals with new, improved seals; modification of the fairing panels;
[[Page 22817]]
and installation of new bulkheads; which eliminates the need for the repetitive inspections.
Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified Airbus Service Bulletin A310-53-2078, Revision 1, as mandatory; and Airbus Service Bulletin A310-53-2083, Revision 02, as recommended; and issued French airworthiness directives 97-175-228(B) R1 and 98-450-261(B), both dated November 18, 1998, in order to assure the continued airworthiness of these airplanes in France.
FAA's Conclusions
This airplane model is manufactured in France 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 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 require accomplishment of the actions specified in the service bulletins described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletins
Operators should note that, unlike the procedures described in Airbus Service Bulletin A310-53-2078, Revision 1, this proposed AD would not permit further flight if cracks are detected in the support brackets of the wing-to-fuselage fairing. The FAA has determined that, because of the safety implications and consequences associated with such cracking, any subject support bracket of the wing-to-fuselage fairing that is found to be cracked must be replaced prior to further flight.
Cost Impact
The FAA estimates that 47 airplanes of U.S. registry would be affected by this proposed AD.
It would take approximately 2 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $5,640, or $120 per airplane, per inspection cycle.
It would take approximately 6 work hours per airplane to accomplish the proposed replacement, modification, and installation, at an average labor rate of $60 per work hour. Required parts would cost approximately $1,690 per airplane. Based on these figures, the cost impact of the replacement, modification and installation proposed by this AD on U.S. operators is estimated to be $96,350, or $2,050 per airplane.
The cost impact figures discussed above are 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:
Airbus Industrie: Docket 99-NM-17-AD.
Applicability: Model A310-200 series airplanes, on which Airbus Modification 4800 or 4906 has been accomplished; and Model A310-300 series airplanes on which Airbus Modification 11758 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 prevent reduced structural integrity of the support brackets of the upper wing-to-fuselage fairing, which could result in loss of the wing-to-fuselage fairings during flight, and consequent structural damage to the airplane, accomplish the following:
Initial/Repetitive Inspections
(a) Prior to the accumulation of 5,000 total flight hours or within 1,200 flight hours after the effective date of this AD, whichever occurs later: Perform a detailed visual inspection to detect cracked or broken support brackets of the upper wing-to- fuselage fairings, in accordance with Airbus Service Bulletin A310- 53-2078, Revision 1, dated March 24, 1997. Repeat the detailed visual inspection thereafter at intervals not to exceed 2,500 flight hours.
Corrective Action
(b) If any discrepancy is detected during any inspection required by paragraph (a) of this AD, prior to further flight, replace the discrepant support bracket with a new bracket in accordance with Airbus Service Bulletin A310-53-2078, Revision 1, dated March 24, 1997. Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 2,500 flight hours.
Terminating Action
(c) Within 2 years after the effective date of this AD, accomplish the requirements of paragraphs (c)(1) and (c)(2) of this AD.
(1) Perform the initial inspection required by paragraph (a) of this AD in accordance
[[Page 22818]]
with Airbus Service Bulletin A310-53-2078, Revision 1, dated March 24, 1997.
(2) Replace the fairing seals with new, improved seals; modify the fairing panels; and install new bulkheads; in accordance with Airbus Service Bulletin A310-53-2083, Revision 02, dated May 5, 1998. Accomplishment of these actions constitutes terminating action for the repetitive inspection 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 2: 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 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 3: The subject of this AD is addressed in French airworthiness directives 97-175-228(B) R1 and 98-450-261(B), both dated November 18, 1998.
Issued in Renton, Washington, on April 21, 1999. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-10604Filed4-27-99; 8:45 am]
BILLING CODE 4910-13-P
