[Federal Register Volume 62, Number 19 (Wednesday, January 29, 1997)]
[Proposed Rules]
[Pages 4208-4211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2224]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-44-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A310 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Airbus Model A310 series 
airplanes. This proposal would require inspections of the lower door 
surrounding structure to detect cracks and corrosion, and repair, if 
necessary. This proposal also would require inspections to detect 
cracking of the holes of the corner doublers, the fail-safe ring, and 
the door frames of the door structures; and repair, if necessary. In 
addition, this proposal would provide for optional terminating action 
for certain inspections. This proposal is prompted by reports 
indicating that corrosion was found between the scuff plates at exit 
and cargo doors, and fatigue cracks originated from certain fastener 
holes located in adjacent structure. The actions specified by the 
proposed AD are intended to detect and correct such corrosion and 
fatigue cracking, which could result in reduced structural integrity of 
the door surroundings.

DATES: Comments must be received by March 10, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-44-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: Charles Huber, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2589; fax (206) 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 96-NM-44-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-103, Attention: Rules 
Docket No.

[[Page 4209]]

96-NM-44-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, has notified the FAA that an unsafe 
condition may exist on all Airbus Model A310 series airplanes. The DGAC 
advises that it has received reports indicating that corrosion was 
found behind the scuff plates at passenger/crew doors, emergency exits, 
and the bulk cargo door. The DGAC also advises that results of 
structural fatigue testing have revealed that cracks were found on the 
corner doublers of the forward, mid, and aft passenger/crew door 
frames; and, after various simulated flights, on the fail-safe ring and 
frames 14 and 16A of the forward passenger/crew door. After 50,000 
simulated flights, cracks measuring between 8.0 mm and 109.0 mm were 
found on the forward door frames and fail-safe ring. On the mid door 
frame, a 53.0 mm crack was found after 60,493 simulated flights. A 
crack which measured 32.0 mm was found on the aft door frame after 
106,000 simulated flights. In all cases, the cracks originated at the 
fastener holes. In addition, cracks originating from corner doubler 
edges were found at the aft passenger/crew doors.
    Such corrosion and cracking, if not detected and corrected, could 
result in reduced structural integrity of the door surroundings.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A310-53-2030, Revision 5, dated 
March 6, 1991, which describes procedures for a one-time inspection to 
detect cracks and corrosion in the areas behind the scuff plates at 
passenger/crew doors, emergency exits, and the bulk cargo door, and 
repair, if necessary. Airbus also has issued Service Bulletin A310-53-
2041, Revision 2, dated July 2, 1996, which describes procedures for 
corresponding repetitive inspections in these areas, and repair, if 
necessary.
    In addition, Airbus has issued Service Bulletin A310-53-2037, 
Revision 1, dated April 29, 1992. This service bulletin describes 
procedures for repetitive inspections to detect cracking of the holes 
of the corner doublers, the fail-safe ring, and the door frames at the 
left-and right-hand forward, mid, and aft passenger/crew door 
structures; and repair, if necessary.
    Airbus also has issued Service Bulletin A310-53-2017, Revision 7, 
dated February 25, 1992, which describes procedures for modification of 
the passenger/crew door frames. This modification consists of 
performing cold expansion procedures on the fastener holes in door 
frames, corner doublers, and fail-safe rings; and installing oversized 
Hi-Lok fasteners and additional steel doublers at door frame corners, 
where necessary, to improve the fatigue life of the corner doublers, 
fail-safe rings, and door frames. Accomplishment of the modification 
eliminates the need for the repetitive inspections specified in Airbus 
Service Bulletin A310-53-2037.
    The DGAC classified the inspection service bulletins as mandatory 
and issued French airworthiness directive 91-132-124(B), dated June 26, 
1991, as amended by a Correction, dated August 21, 1991, in order to 
assure the continued airworthiness of these airplanes in France. (The 
DGAC did not classify the modification service bulletin as mandatory.)

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 inspections of the 
lower door surrounding structure to detect cracks and corrosion, and 
repair, if necessary. The proposed AD also would require inspections to 
detect cracking of the holes of the corner doublers, the fail-safe 
ring, and the door frames of the door structures; and repair, if 
necessary. In addition, the proposed AD would provide for optional 
terminating action for certain inspections. The actions would be 
required to be accomplished in accordance with the service bulletins 
described previously.
    The FAA has considered the following criteria in allowing 
repetitive inspections of the crack-prone area to be permitted to 
continue indefinitely, even though a positive fix for the unsafe 
condition exists: (1) the design of the airplane is damage tolerant; 
and (2) the proposed interval of the repetitive inspections does not 
require that numerous inspections will be accomplished over the life of 
the airplane.

Cost Impact

    The FAA estimates that 33 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 700 work 
hours per airplane to accomplish the proposed inspections (including 
access and close-up), and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the proposed 
inspections on U.S. operators is estimated to be $1,386,000, or $42,000 
per airplane.
    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.
    Should an operator elect to accomplish the optional terminating 
action that would be provided by this AD action, it would take 
approximately 147 work hours to accomplish it, at an average labor rate 
of $60 per work hour. The cost of required parts would be approximately 
$5,581 per airplane. Based on these figures, the cost impact of the 
optional terminating action would be $14,401 per airplane.

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

[[Page 4210]]

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 96-NM-44-AD.

    Applicability: All Model A310 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 
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 (i) 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 behind the scuff plates at exit 
and cargo doors, and fatigue cracking in certain fastener holes 
located in adjacent structure, which could result in reduced 
structural integrity of the door surroundings, accomplish the 
following:
    (a) Perform an initial inspection of the areas behind the scuff 
plates below the passenger/crew doors and bulk cargo door to detect 
cracks and corrosion, in accordance with Airbus Service Bulletin 
A310-53-2030, Revision 5, dated March 6, 1991; at the applicable 
time specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD. If 
any crack or corrosion is found during this inspection, prior to 
further flight, repair in accordance with the service bulletin. 
Accomplishment of this inspection is not required for the aft 
passenger/crew doors if a steel doubler that covers the entire 
inspection area is installed.
    (1) For any door on which Modification 5382 has been 
accomplished: Perform the initial inspection within 9 years since 
airplane manufacture, or within 1 year after the effective date of 
this AD, whichever occurs later.
    (2) For any door on which Modification 5382 has not been 
accomplished, and on which the procedures described in Airbus 
Service Bulletin A310-53-2004, Revision 2, dated June 17, 1985, or 
Airbus Service Information Letter 53-033, Revision 2, dated November 
23, 1984, have been accomplished: Perform the initial inspection 
within 5 years since airplane manufacture, or within 1 year after 
the effective date of this AD, whichever occurs later.
    (3) For any door on which Modification 5382 has not been 
accomplished, and on which the procedures described in Airbus 
Service Bulletin A310-53-2004, Revision 2, dated June 17, 1985, or 
Airbus Service Information Letter 53-033, Revision 2, dated November 
23, 1984, have not been accomplished: Perform the initial inspection 
within 4 years since airplane manufacture, or within 1 year after 
the effective date of this AD, whichever occurs later.
    (b) Perform repetitive inspections of the areas behind the scuff 
plates below the passenger/crew doors and bulk cargo door to detect 
cracks and corrosion, in accordance with Airbus Service Bulletin 
A310-53-2041, Revision 1, dated March 6, 1991; at the applicable 
times specified in paragraph (b)(1), (b)(2), or (b)(3) of this AD. 
Accomplishment of these inspections is not required for the aft 
passenger/crew doors if a steel doubler that covers the entire 
inspection area is installed.
    (1) For the forward passenger/crew doors, the bulk cargo door, 
and the aft passenger/crew doors, except the upper and lower edges 
of the fail-safe ring and the upper edges of the corner doubler, on 
all Model A310-200 and -300 series airplanes: Perform the first 
inspection within 5 years after accomplishing the inspection 
required by paragraph (a) of this AD; and repeat the inspection 
thereafter at intervals not to exceed 5 years.
    (2) For the upper and lower edges of the fail-safe ring and the 
upper edges of the corner doubler of the aft passenger/crew door on 
all Model A310-200 series airplanes: Perform the first inspection 
within 5 years or 12,000 landings after accomplishing the inspection 
required by paragraph (a) of this AD, whichever occurs first; and 
repeat the inspection thereafter at intervals not to exceed 5 years 
or 12,000 landings, whichever occurs first.
    (3) For the upper and lower edges of the fail-safe ring and the 
upper edges of the corner doubler of the aft passenger/crew door on 
all Model A310-300 series airplanes: Perform the first inspection 
within 5 years or 7,000 landings after accomplishing the inspection 
required by paragraph (a) of this AD, whichever occurs first; and 
repeat the inspection thereafter at intervals not to exceed 5 years 
or 7,000 landings, whichever occurs first.
    (c) If any crack is found during any inspection required by 
paragraph (b) of this AD, prior to further flight, repair in 
accordance with Airbus Service Bulletin A310-53-2041, Revision 1, 
dated March 6, 1991. Thereafter, perform the repetitive inspections 
required by paragraph (b) of this AD at the applicable times 
specified in paragraphs (b)(1), (b)(2), and (b)(3) of this AD.
    (d) If any corrosion is found during any inspection required by 
paragraph (b) of this AD, prior to further flight, repair in 
accordance with Airbus Service Bulletin A310-53-2041, Revision 1, 
dated March 6, 1991. Thereafter, perform the repetitive inspections 
required by paragraph (b) of this AD at the applicable time 
specified in paragraph (d)(1) or (d)(2) of this AD.
    (1) For Model A310-200 series airplanes: Inspect at intervals 
not to exceed 5 years or 9,600 landings, whichever occurs first.
    (2) For Model A310-300 series airplanes: Inspect at intervals 
not to exceed 5 years or 5,600 landings, whichever occurs first.
    (e) Perform an inspection to detect cracking of the holes of the 
corner doublers, the fail-safe ring, and the door frames of the 
left-and right-hand forward, mid, and aft passenger/crew door 
structures, in accordance with Airbus Service Bulletin A310-53-2037, 
Revision 1, dated April 29, 1992, and at the applicable times 
specified in paragraphs (e)(1), (e)(2), or (e)(3) of this AD.
    (1) For the upper corners of the forward doors: Inspect prior to 
the accumulation of 20,000 total landings, or within 2,000 landings 
after the effective date of this AD, whichever occurs later.
    (2) For the lower corners of the forward doors: Inspect prior to 
the accumulation of 20,000 total landings, or within 4,000 landings 
after the effective date of this AD, whichever occurs later.
    (3) For the upper and lower corners of the aft doors, and for 
the parts underneath the corners of the upper door frames: Inspect 
prior to the accumulation of 20,000 total landings, or within 4,000 
landings after the effective date of this AD, whichever occurs 
later.
    (f) Repeat the inspections required by paragraph (e) of this AD 
at the applicable times specified in paragraphs (f)(1), (f)(2), 
(f)(3), (f)(4), and (f)(5).
    (1) For the upper corners of the forward doors: Inspect at 
intervals not to exceed 6,000 landings.
    (2) For the lower corners of the forward doors: Inspect at 
intervals not to exceed 10,000 landings.
    (3) For the upper and lower corners of the aft doors on which an 
inspection required by paragraph (e) of this AD was accomplished 
using a Roto test technique: Inspect at intervals not to exceed 
8,000 landings.
    (4) For the upper and lower corners of the aft doors on which an 
inspection required by paragraph (e) of this AD was accomplished 
using an X-ray technique: Inspect at intervals not to exceed 3,500 
landings.
    (5) For the areas around the fasteners in the vicinity of 
stringer 12 on the upper door frames of the aft doors on which an 
inspection required by paragraph (e) of this AD was accomplished 
using a visual technique: Inspect at intervals not to exceed 6,900 
landings.
    (g) If any crack is found during any inspection required by 
paragraph (e) or (f) of this AD: Prior to further flight, accomplish 
the requirement of paragraph (g)(1) or (g)(2) of this AD, as 
applicable.
    (1) If any crack is found, and the crack can be eliminated using 
the method specified in Airbus Service Bulletin A310-53-2037, 
Revision 1, dated April 29, 1992: Prior to further flight, repair 
the crack in accordance with that service bulletin.

[[Page 4211]]

    (2) If any crack is found, and the crack cannot be eliminated 
using the method specified in Airbus Service Bulletin A310-53-2037, 
Revision 1, dated April 29, 1992: Prior to further flight, repair 
the crack in accordance with a method approved by the Manager, 
Standardization Branch, ANM-113, FAA, Transport Airplane 
Directorate.
    (h) Modification of the passenger/crew door frames in accordance 
with Airbus Service Bulletin A310-53-2017, Revision 7, dated 
February 25, 1992, constitutes terminating action for the repetitive 
inspections required by paragraph (f) of this AD.
    (i) 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, Standardization Branch, ANM-113. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (j) 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 January 23, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-2224 Filed 1-28-97; 8:45 am]
BILLING CODE 4910-13-P