[Federal Register Volume 64, Number 205 (Monday, October 25, 1999)]
[Proposed Rules]
[Pages 57409-57413]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27792]


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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).

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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

[[Page 57410]]

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 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-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

[[Page 57411]]

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

    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 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

[[Page 57412]]

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.


[[Page 57413]]


    Issued in Renton, Washington, on October 19, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-27792 Filed 10-22-99; 8:45 am]
BILLING CODE 4910-13-P