[Federal Register Volume 63, Number 236 (Wednesday, December 9, 1998)]
[Proposed Rules]
[Pages 67813-67816]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-32620]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-106-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300 and A300-600 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

[[Page 67814]]

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Airbus Model A300 and 
A300-600 series airplanes. This proposal would require replacement of 
the rivets that attach the pressurized floor panel to gantries 4 and 5 
with new titanium alloy bolts. This proposal also would require, for 
certain airplanes, repetitive inspections to detect discrepancies of 
the rivets; and corrective actions, if necessary. 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 failure of the rivets that 
attach the pressurized floor panel to gantries 4 and 5, which could 
result in the loss of the floor panel and consequent rapid 
decompression of the airplane.

DATES: Comments must be received by January 8, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-106-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 filed in 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-106-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-106-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 A300 and A300-600 series 
airplanes. The DGAC advises that, during maintenance on a Model A300 
series airplane, maintenance personnel discovered several rivets had 
been sheared off that attach the pressurized floor panel to gantry 5 
between frames 47 and 48. Those rivets are also used to attach the 
pressurized floor panel to gantry 4. Investigation has revealed that 
alternate bending stress under the rivet heads caused the rivets to 
break. The cause of the stress has been attributed to an alternate 
shear load between the pressurized floor panel and gantries 4 and 5. 
Failure of the rivets, if not corrected, could result in the loss of 
the floor panel and consequent rapid decompression of the airplane.
    The rivets that attach the pressurized floor panel to gantries 4 
and 5 on certain Model A300-600 series airplanes are similar in design 
to those on Model A300 series airplanes; therefore, both models may be 
subject to the same unsafe condition.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A300-53-0331, dated March 18, 
1997 (for Model A300 series airplanes), and A300-53-6107, dated March 
18, 1997 (for Model A300-600 series airplanes), which describe 
procedures for replacement of the rivets between frames 47 and 48 at 
gantries 4 and 5 with new titanium alloy bolts.
    For certain airplanes, these service bulletins also describe 
procedures for repetitive detailed visual inspections to detect 
discrepancies of the existing rivets; corrective actions, if necessary; 
and eventual replacement of the plain aluminum rivets or blind rivets 
with titanium alloy bolts.
    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 mandatory and issued French 
airworthiness directive 97-176-229(B), dated August 13, 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 require replacement of the 
existing rivets that attach the pressurized floor panel to gantries 4 
and 5 with new titanium alloy bolts. For certain airplanes, this 
proposal would require repetitive inspections to detect discrepancies 
of the existing rivets; corrective actions, if necessary; and eventual 
replacement of the plain aluminum rivets or blind rivets that attach 
the pressurized floor panel to gantries 4 and 5 with titanium alloy 
bolts.

Cost Impact

    The FAA estimates that 24 Airbus Model A300 series airplanes of 
U.S. registry would be affected by this proposed AD. It would take 
approximately 26 work hours per

[[Page 67815]]

airplane to accomplish the proposed replacement, at an average labor 
rate of $60 per work hour. Required parts would cost between $3,160 and 
$3,520 per airplane, depending on the service kit purchased. Based on 
these figures, the cost impact of the replacement proposed by this AD 
on U.S. operators of Airbus Model A300 series airplanes is estimated to 
be as low as $4,720 per airplane or as high as $5,080 per airplane.
    The FAA estimates that 61 Airbus Model A300-600 series airplanes of 
U.S. registry would be affected by this proposed AD. It would take 
approximately 26 work hours per airplane to accomplish the proposed 
replacement, at an average labor rate of $60 per work hour. Required 
parts would cost between $3,530 and $3,550 per airplane, depending on 
the service kit purchased. Based on these figures, the cost impact of 
the replacement proposed by this AD on U.S. operators of Airbus Model 
A300-600 series airplanes is estimated to be as low as $5,090 per 
airplane or as high as $5,110 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.
    Should an operator be required to accomplish the proposed 
inspection, it would take approximately 1 work hour to accomplish, at 
an average labor rate of $60 per work hour. Based on this figure, the 
cost impact of the inspection proposed by this AD on U.S. operators of 
Airbus Model A300 and A300-600 series airplanes is estimated to be $60 
per airplane, per inspection cycle.

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

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Airbus Industrie: Docket 98-NM-106-AD.

    Applicability: Model A300 and A300-600 series airplanes on which 
Airbus Modification 11523 (reference Airbus Service Bulletins A300-
53-0331 and A300-53-6107, both dated March 18, 1997) 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 (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 failure of the rivets that attach the pressurized 
floor panel to gantries 4 and 5, which could result in the loss of 
the floor panel and consequent rapid decompression of the airplane, 
accomplish the following:
    (a) Accomplish paragraph (a)(1), or paragraphs (a)(2) and 
(a)(3), of this AD at the times specified in those paragraphs in 
accordance with Airbus Service Bulletin A300-53-0331, dated March 
18, 1997 (for Airbus Model A300 series airplanes); or Airbus Service 
Bulletin A300-53-6107, dated March 18, 1997 (for Airbus Model A300-
600 series airplanes); as applicable.
    (1) Replace the rivets that attach the pressurized floor panel 
to gantries 4 and 5 with new titanium alloy bolts, at the applicable 
time specified in paragraph (a)(1)(i), (a)(1)(ii), (a)(1)(iii), or 
(a)(1)(iv) of this AD.
    (i) For Airbus Model A300-600 series airplanes, replace the 
rivets prior to the accumulation of 7,150 total flight cycles.
    (ii) For Airbus Model A300 B4-203 series airplanes, replace the 
rivets prior to the accumulation of 10,000 total flight cycles.
    (iii) For Airbus Model A300 B4-2C and B4-103 series airplanes, 
replace the rivets prior to the accumulation of 12,300 total flight 
cycles.
    (iv) For Airbus Model A300 B2-1C, B2-203, and B2K-3C series 
airplanes, replace the rivets prior to the accumulation of 14,600 
total flight cycles.
    (2) Perform a detailed visual inspection to detect any broken or 
discrepant rivets that attach the pressurized floor panel to 
gantries 4 and 5, at the applicable time specified in paragraph 
(a)(2)(i), (a)(2)(ii), (a)(2)(iii), or (a)(2)(iv) of this AD. Repeat 
the inspection thereafter at intervals not to exceed 350 flight 
cycles until accomplishment of the action required by paragraph 
(a)(3) of this AD.
    (i) For Airbus Model A300-600 series airplanes, inspect the 
rivets prior to the accumulation of 7,500 total flight cycles, or 
within 350 flight cycles after the effective date of this AD, 
whichever occurs later.
    (ii) For Airbus Model A300 B4-203 series airplanes, inspect the 
rivets prior to the accumulation of 10,350 total flight cycles, or 
within 350 flight cycles after the effective date of this AD, 
whichever occurs later.
    (iii) For Airbus Model A300 B4-2C and B4-103 series airplanes, 
inspect the rivets prior to the accumulation of 12,650 total flight 
cycles, or within 350 flight cycles after the effective date of this 
AD, whichever occurs later.
    (iv) For Airbus Model A300 B2-1C, B2-203, and B2K-3C series 
airplanes, inspect the rivets prior to the accumulation of 14,950 
total flight cycles, or within 350 flight cycles after the effective 
date of this AD, whichever occurs later.
    (3) Within 3,000 flight cycles after the effective date of this 
AD, replace the rivets that attach the pressurized floor panel to 
gantries 4 and 5 with new titanium alloy bolts in accordance with 
the applicable service bulletin. Accomplishment of this replacement 
constitutes terminating action for the repetitive inspections.
    (b) If any discrepant or broken rivet is detected during any 
inspection specified in paragraph (a)(2) of this AD, prior to 
further flight, accomplish either paragraph (b)(1) or (b)(2) of this 
AD, as applicable, in accordance with Airbus Service Bulletin A300-
53-0331, dated March 18, 1997 (for Airbus Model A300 series 
airplanes); or Airbus Service Bulletin A300-53-6107, dated March 18, 
1997 (for Airbus Model A300-600 series airplanes).
    (1) If less than 15 discrepant or broken rivets are detected, 
prior to further flight, replace the discrepant or broken rivets 
with serviceable rivets and continue the repetitive inspections, in 
accordance with the applicable service bulletin, until

[[Page 67816]]

accomplishment of the action required by paragraph (a)(3) of this 
AD.
    (2) If 15 or more discrepant or broken rivets are detected, 
prior to further flight, replace all the rivets that attach the 
pressurized floor panel to gantries 4 and 5 with new titanium alloy 
bolts, in accordance with the applicable service bulletin. 
Accomplishment of this replacement constitutes terminating action 
for the repetitive inspections required by this AD.
    (c) 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.

    (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 3: The subject of this AD is addressed in French 
airworthiness directive 97-176-229(B), dated August 13, 1997.

    Issued in Renton, Washington, on December 2, 1998.
John W. McGraw,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-32620 Filed 12-8-98; 8:45 am]
BILLING CODE 4910-13-U