[Federal Register Volume 63, Number 56 (Tuesday, March 24, 1998)]
[Proposed Rules]
[Pages 14044-14047]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-7525]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-341-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A300, A310, and A300-600 
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 all Airbus Model A300, A310, and 
A300-600 series airplanes. This proposal would require repetitive 
inspections to detect corrosion and cracks on the bottom area of the 
wing skin, and corrective action, 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 detect and correct corrosion and cracks 
on the bottom area of the wing skin, which could result in reduced 
structural integrity of the airplane.


[[Page 14045]]


DATES: Comments must be received by April 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-341-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 97-NM-341-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-341-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 all Airbus Model A300, A310, and A300-600 series 
airplanes. The DGAC advises that it has received reports of corrosion 
on the lower wing root joint, on the bottom wing skin, inboard and 
outboard of the external lower surface splice. Most of the corrosion 
was found in the area aft of frame 43, and around fasteners, starting 
from the edges of the countersinks. Such corrosion could lead to 
cracking in this area. This condition, if not detected and corrected in 
a timely manner, could result in reduced structural integrity of the 
airplane.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A300-57-0204, dated December 4, 
1995 (for Model A300 series airplanes); A310-57-2061, dated December 4, 
1995 (for Model A310 series airplanes); and A300-57-6047, Revision 01, 
dated October 16, 1996, as revised by Change Notice 1.A., dated 
February 24, 1997 (for Model A300-600 series airplanes). These service 
bulletins describe procedures for repetitive detailed visual 
inspections to detect corrosion and cracks of the bottom wing skin 
area, inboard and outboard of the rib 1 external lower surface splice, 
between frame 40 and frame 47. The service bulletins also describe 
procedures for removal of any corrosion found, application of 
protective treatment, and non-destructive inspection for cracks, if 
necessary.
    The DGAC classified these service bulletins as mandatory and issued 
French airworthiness directive 97-006-210(B), dated January 2, 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 
Sec. 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 the Proposal and the Related Service Bulletins

    The proposed rule would differ from the Airbus service bulletins 
described previously in that, unlike the compliance time threshold and 
intervals provided in the service bulletins, this proposed AD would 
reference tables that provide compliance time thresholds and intervals 
in flight cycles and corresponding flight hours for each airplane 
model. The thresholds and intervals defined in the service bulletins 
are based on an Average Flight Time (AFT) for each airplane model. For 
those airplanes that are operated with a flight duration different from 
the AFT, an adjustment must be made to the thresholds and intervals. To 
provide clarification of the appropriate thresholds and intervals, 
Tables 1, 2, 3, 4, and 5 have been included in the proposed AD to 
provide specific thresholds and intervals, and to eliminate the need 
for operators to calculate differing adjustments for various AFT's.
    Operators also should note that the service bulletins specify that 
the manufacturer may be contacted for disposition of certain repair 
conditions. However, this proposal would require the repair of those 
conditions to be accomplished in accordance with a method approved by 
the FAA.

Cost Impact

    The FAA estimates that 49 Model A300 and A310 series airplanes, and 
51 Model A300-600 series airplanes, of U.S. registry would be affected 
by this proposed AD, that it would take approximately 8 work hours per 
inspection cycle to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$48,000, or $480 per airplane, per inspection cycle.

[[Page 14046]]

    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

    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:  Docket 97-NM-341-AD.

    Applicability: All Model A300, A310, and A300-600 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 (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 detect and correct corrosion and cracks on the bottom wing 
skin area, which could result in reduced structural integrity of the 
airplane, accomplish the following:
    (a) At the time specified in paragraph (a)(1), (a)(2), (a)(3), 
or (a)(4) of this AD, as applicable: Except as required by 
paragraphs (b) and (c) of this AD, perform an inspection for 
corrosion and cracks on the bottom wing skin area, and accomplish 
follow-on corrective actions, in accordance with Airbus Service 
Bulletin A300-57-0204, dated December 4, 1995 (for Model A300 series 
airplanes); A310-57-2061, dated December 4, 1995 (for Model A310 
series airplanes); or A300-57-6047, Revision 01, dated October 16, 
1996, as revised by Change Notice 1.A., dated February 24, 1997 (for 
Model A300-600 series airplanes); as applicable; subsequently 
referred to in this AD as the ``applicable'' service bulletins. 
Thereafter, repeat the inspection at intervals not to exceed 5 
years.
    (1) For airplanes with 5 years or less since date of 
manufacture: Prior to the accumulation of 5 years since date of 
manufacture or within 18 months after the effective date of this AD, 
whichever occurs later.
    (2) For airplanes with more than 5 years, but less than 15 years 
since date of manufacture: Within 18 months after the effective date 
of this AD.
    (3) For airplanes with more than 15 years, but less than 20 
years since date of manufacture: Within 12 months after the 
effective date of this AD.
    (4) For airplanes with more than 20 years since date of 
manufacture: Within 6 months after the effective date of this AD.
    (b) If any corrosion or crack is found during an inspection 
required by paragraph (a) of this AD, and the applicable service 
bulletin specifies to contact Airbus for an appropriate action: 
Prior to further flight, repair in accordance with a method approved 
by the Manager, International Branch, ANM-116, FAA, Transport 
Airplane Directorate.
    (c) If any crack is found during an inspection required by 
paragraph (a) of this AD, and the applicable service bulletin 
specifies to refer to Table B, Figure 4, of the service bulletin to 
determine the fatigue inspection threshold and interval: Use Table 
1, 2, 3, 4, or 5, of this AD, as applicable, to determine the 
fatigue inspection threshold and interval in flight cycles (FC) or 
flight hours (FH).

                Table 1.--Airbus Service Bulletin A300-57-204 (Model A300 B2) Fatigue Inspection                
----------------------------------------------------------------------------------------------------------------
                                                          Detailed visual                                       
                                 Threshold (FC or FH,   interval (FC or FH,     NDT (HFEC) interval (FC or FH,  
             Area                  whichever occurs       whichever occurs          whichever occurs first)     
                                        first)                 first)                                           
----------------------------------------------------------------------------------------------------------------
1, 2, 3a \1\..................  10,400 FC or 15,800    10,400 FC or 15,800    10,400 FC or 15,800 FH.           
                                 FH.                    FH.                                                     
3b, 4a \2\....................  7,200 FC or 11,000 FH  2,500 FC or 3,800 FH.  6,300 FC or 9,600 FH.             
4b............................  10,400 FC or 15,800    10,400 FC or 15,800    10,400 FC or 15,800 FH.           
                                 FH.                    FH.                                                     
5, 6..........................  9,900 FC or 15,100 FH  8,700 FC or 13,200 FH  9,900 FC or 15,100 FH.            
7, 8..........................  6,600 FC or 10,000 FH  5,000 FC or 7,700 FH.  6,400 FC or 9,700 FH.             
----------------------------------------------------------------------------------------------------------------
\1\ Area 3, as defined by Table B, Table 4, of SB A300-57-0204, has been split into areas 3a and 3b with a      
  borderline between stiffener 43.2 and lattice flange 44 for Tables 1, 2, and 3 of this AD.                    
\2\ Area 4, as defined by Table B, Table 4, of SB A300-57-0204, has been split into areas 4a and 4b with a      
  borderline between lattice flange 44 and stiffener 44.1 for Tables 1, 2, and 3 of this AD.                    


              Table 2.--Airbus Service Bulletin A300-57-204 (Model A300 B4-100) Fatigue Inspection              
----------------------------------------------------------------------------------------------------------------
                                                          Detailed visual                                       
                                 Threshold (FC or FH,   interval (FC or FH,     NDT (HFEC) interval (FC or FH,  
             Area                  whichever occurs       whichever occurs          whichever occurs first)     
                                        first)                 first)                                           
----------------------------------------------------------------------------------------------------------------
1, 2, 3a......................  9,500 FC or 15,600 FH  8,600 FC or 14,200 FH  9,500 FC or 15,600 FH.            

[[Page 14047]]

                                                                                                                
 3b, 4a.......................  6,700 FC or 12,000 FH  2,000 FC or 3,300 FH.  5,000 FC or 8,200 FH.             
4b............................  9,500 FC or 15,600 FH  8,600 FC or 14,200 FH  9,500 FC or 15,600 FH.            
 5, 6.........................  8,200 FC or 13,400 FH  7,200 FC or 11,900 FH  8,200 FC or 13,400 FH.            
7, 8..........................  4,600 FC or 7,600 FH.  3,600 FC or 5,900 FH.  4,500 FC or 7,400 FH              
----------------------------------------------------------------------------------------------------------------


               Table 3.--Airbus Service Bulletin A300-57-204 (Model A300B4-200) Fatigue Inspection              
----------------------------------------------------------------------------------------------------------------
                                                          Detailed visual                                       
                                 Threshold (FC or FH,   interval (FC or FH,     NDT (HFEC) interval (FC or FH,  
             Area                  whichever occurs       whichever occurs          whichever occurs first)     
                                        first)                 first)                                           
----------------------------------------------------------------------------------------------------------------
1, 2, 3a......................  9,900 FC or 21,100 FH  9,000 FC or 19,200 FH  9,900 FC or 12,100 FH.            
3b, 4a........................  7,000 FC or 14,900 FH  2,100 FC or 4,500 FH.  5,200 FC or 11,100 FH.            
4b............................  9,900 FC or 21,100 FH  9,000 FC or 19,200 FH  9,900 FC or 21,100 FH.            
5, 6..........................  8,500 FC or 18,100 FH  7,500 FC or 16,000 FH  8,500 FC or 18,100 FH.            
7, 8..........................  4,800 FC or 10,200 FH  3,700 FC or 7,900 FH.  4,700 FC or 10,000 FH.            
----------------------------------------------------------------------------------------------------------------


         Table 4.--Airbus Service Bulletin A310-57-2061 (Model A310-200 and A310-300) Fatigue Inspection        
----------------------------------------------------------------------------------------------------------------
                                                          Detailed visual                                       
                                 Threshold (FC or FH,   interval (FC or FH,     NDT (HFEC) interval (FC or FH,  
             Area                  whichever occurs       whichever occurs          whichever occurs first)     
                                        first)                 first)                                           
----------------------------------------------------------------------------------------------------------------
1.............................  12,800 FC or 36,600    10,500 FC or 29,900    12,800 FC or 36,600 FH.           
                                 FH.                    FH.                                                     
2.............................  5,700 FC or 16,300 FH  4,600 FC or 13,100 FH  5,700 FC or 16,300 FH.            
3, 5..........................  5,100 FC or 14,700 FH  4,100 FC or 11,800 FH  5,100 FC or 14,700 FH.            
4.............................  4,500 FC or 12,800 FH  1,800 FC or 5,100 FH.  4,500 FC or 12,800 FH.            
6.............................  19,400 FC or 55,300    16,500 FC or 47,000    19,400 FC or 55,300 FH.           
                                 FH.                    FH.                                                     
7.............................  16,300 FC or 46,500    13,800 FC or 39,500    16,300 FC or 46,500 FH.           
                                 FH.                    FH.                                                     
----------------------------------------------------------------------------------------------------------------


               Table 5.--Airbus Service Bulletin A300-57-6047 (Model A300-600) Fatigue Inspection               
----------------------------------------------------------------------------------------------------------------
                                                          Detailed visual                                       
                                 Threshold (FC or FH,   interval (FC or FH,     NDT (HFEC) interval (FC or FH,  
             Area                  whichever occurs       whichever occurs          whichever occurs first)     
                                        first)                 first)                                           
----------------------------------------------------------------------------------------------------------------
1, 2..........................  13,600 FC or 42,900    11,800 FC or 37,000    15,500 FC or 48,800 FH.           
                                 FH.                    FH.                                                     
 3............................  6,500 FC or 20,400 FH  5,800 FC or 18,400 FH  6,900 FC or 21,600 FH.            
4, 6..........................  4,800 FC or 15,100 FH  4,500 FC or 14,200 FH  5,000 FC or 15,700 FH.            
5.............................  2,100 FC or 6,500 FH.  900 FC or 3,000 FH...  2,100 FC or 6,500 FH.             
7.............................  5,700 FC or 18,100 FH  5,500 FC or 17,200 FH  6,300 FC or 19,800 FH.            
8.............................  2,400 FC or 7,400 FH.  2,100 FC or 6,500 FH.  2,400 FC or 7,400 FH.             
----------------------------------------------------------------------------------------------------------------

    (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. 
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.

    (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 directive 97-006-210(B), dated January 2, 1997.

    Issued in Renton, Washington, on March 17, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-7525 Filed 3-23-98; 8:45 am]
BILLING CODE 4910-13-U