[Federal Register Volume 64, Number 206 (Tuesday, October 26, 1999)]
[Proposed Rules]
[Pages 57602-57605]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27939]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-240-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR72 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Aerospatiale Model ATR72 series 
airplanes, that would have required initial and repetitive inspections 
to detect fatigue cracking in certain areas of the fuselage, and 
corrective actions, if necessary. That proposal was prompted by 
issuance of mandatory continuing airworthiness information by a foreign 
civil airworthiness authority. This new action revises the proposed 
rule by correcting an omission of the compliance time for 
accomplishment of the initial inspection for certain airplanes. The 
actions specified by this new proposed AD are intended to prevent 
fatigue cracking of the fuselage and the passenger and service doors, 
which could result in reduced structural integrity of the airplane.

DATES: Comments must be received by November 26, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-240-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,

[[Page 57603]]

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-240-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-240-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Aerospatiale Model ATR72 series airplanes, was published as a 
notice of proposed rulemaking (NPRM) in the Federal Register on January 
5, 1999 (64 FR 438). That NPRM would have required initial and 
repetitive inspections to detect fatigue cracking in certain areas of 
the fuselage, and corrective actions, if necessary. That NPRM was 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. That condition, if not 
corrected, could result in fatigue cracking of the fuselage and the 
passenger and service doors, which could result in reduced structural 
integrity of the airplane.

Actions Since Issuance of Previous Proposal

    Due consideration has been given to the comments received in 
response to that NPRM.

Omission of Compliance Time

    Two commenters state that paragraph (a) of the proposed AD does not 
address a time frame for accomplishment of the proposed actions. Both 
commenters note that the compliance deadline in the service bulletin is 
27,000 total flight cycles, and assume that the FAA's intent was to 
follow that compliance time.
    The FAA acknowledges that paragraph (a) of the proposed AD does not 
specify a compliance time. It was the FAA's intent to follow the same 
compliance time as that specified in the service bulletin; the 
compliance time was inadvertently omitted from the NPRM. This error has 
been corrected, and, due to this omission, the revised rule will be 
issued as a supplemental NPRM.

Conclusion

    Since this change expands the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Request To Allow Latest Service Bulletin Revisions

    One commenter states that for paragraphs (b) and (c), respectively, 
ATR Service Bulletins ATR72-53-1013 and ATR72-53-1019, both Revision 3, 
were issued January 22, 1999. The commenter requests that the AD 
reference Revision 3 of both of these bulletins instead of Revision 2, 
as currently referenced. Revision 3 of the service bulletins provides a 
compliance time of 36,000 total flight cycles, which is consistent with 
the French AD and this NPRM.
    The FAA concurs with the commenter's request. Revisions 2 and 3 of 
the service bulletins mentioned above are technically equivalent. This 
supplemental NPRM will be revised to reference Revision 3; however, 
Note 2 is revised to also allow compliance with Revision 2 prior to the 
effective date of the AD.

Cost Impact

    The FAA estimates that 39 airplanes of U.S. registry would be 
affected by this proposed AD.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-53-1018 (14 U.S.-sregistered airplanes), it would take 
approximately 250 work hours per airplane to accomplish the proposed 
actions, 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 these actions proposed by this AD on U.S. operators 
is estimated to be $348,320, or $24,880 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-52-1013, Revision 2 (2 U.S.-registered airplanes), it 
would take approximately 3 work hours per airplane to accomplish the 
proposed actions, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of these actions proposed by this AD 
on U.S. operators is estimated to be $360, or $180 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-52-1019, Revision 2 (2 U.S.-registered airplanes), it 
would take approximately 100 work hours per airplane to accomplish the 
proposed actions, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of these actions proposed by this AD 
on U.S. operators is estimated to be $12,000, or $6,000 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-52-1028 (2 U.S.-registered airplanes), it would take 
approximately 5 work hours per airplane to accomplish the proposed 
actions, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of these actions proposed by this AD on U.S. 
operators is estimated to be $600 or $300 per airplane, per inspection 
cycle.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-52-1033, and ATR72-52-1029, Revision 1 (2 U.S.-
registered airplanes), it would take approximately 145 work hours per 
airplane to accomplish the proposed door stop fitting replacement, at 
an average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the stop fittings replacement 
proposed by this AD on

[[Page 57604]]

U.S. operators is estimated to be $17,400 or $8,700 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-53-1021, Revision 1 (2 U.S.-registered airplanes), it 
would take approximately 30 work hours per airplane to accomplish the 
proposed actions, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of these actions proposed by this AD 
on U.S. operators is estimated to be $3,600, or $1,800 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-53-1014, Revision 2 (2 U.S.-registered airplanes), it 
would take approximately 8 work hours per airplane to accomplish the 
proposed actions, at an average labor rate of $60 per work hour. Based 
on these figures, the cost impact of these actions proposed by this AD 
on U.S. operators is estimated to be $960, or $480 per airplane.
    For airplanes identified in Avions de Transport Regional Service 
Bulletin ATR72-53-1020 (14 U.S.-registered airplanes), it would take 
approximately 6 work hours per airplane to accomplish the proposed 
actions, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of these actions proposed by this AD on U.S. 
operators is estimated to be $5,040, or $360 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

    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:

Aerospatiale: Docket 98-NM-240-AD.

    Applicability: Model ATR72 series airplanes, certificated in any 
category; listed in the following Avions de Transport Regional 
Service Bulletins:
     ATR72-52-1018, dated May 18, 1995;
     ATR72-53-1013, Revision 2, dated March 22, 1993;
     ATR72-53-1019, Revision 2, dated October 15, 1996;
     ATR72-52-1028, dated July 5, 1993;
     ATR72-52-1033, dated April 28, 1995;
     ATR72-52-1029, Revision 1, dated November 16, 1994;
     ATR72-53-1021, Revision 1, dated February 20, 1995;
     ATR72-53-1014, Revision 2, dated October 15, 1992; and
     ATR72-53-1020, dated October 6, 1992.

    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 (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 prevent fatigue cracking of the fuselage and the passenger 
and service doors, which could result in reduced structural 
integrity of the airplane, accomplish the following:
    (a) For airplanes on which Aerospatiale Modification 03191 
(reference Avions de Transport Regional Service Bulletin ATR72-52-
1018, dated May 18, 1995) has not been accomplished: Prior to the 
accumulation of 27,000 total flight cycles, or within 30 days after 
the effective date of this AD, whichever occurs later, perform a 
preliminary inspection of the existing fasteners to determine if the 
fasteners are out of tolerance in accordance with paragraph 2.C.(1) 
of the Accomplishment Instructions of Avions de Transport Regional 
Service Bulletin ATR72-52-1018, dated May 18, 1995. Depending on the 
results of the inspection, prior to further flight, accomplish the 
requirements in paragraphs (a)(1) and (a)(2), or (a)(2) and (a)(3), 
of this AD, as applicable, as specified by paragraph 2.C.(1) of the 
service bulletin.
    (1) Remove the fasteners and inspect the fastener holes to 
determine if they are out of tolerance or cracking, in accordance 
with Part A of the Accomplishment Instructions of the service 
bulletin. Perform a visual inspection of the holes for correct 
tolerance, and a high frequency eddy current (HFEC) inspection for 
cracking.
    (i) If any discrepancy is detected, prior to further flight, 
repair in accordance with Part C of the Accomplishment Instructions 
of the service bulletin.
    (ii) If no discrepancy is detected, prior to further flight, 
replace the cargo compartment door hinges with new hinges in 
accordance with Part A of the Accomplishment Instructions of the 
service bulletin.
    (2) Remove the existing fasteners and inspect the fastener holes 
for correct tolerance in accordance with Part B of the 
Accomplishment Instructions of the service bulletin.
    (i) If any discrepancy is detected, prior to further flight, 
repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, Transport Airplane Directorate; or 
the Direction Generale de l'Aviation Civile (DGAC) or its delegated 
agent.
    (ii) If no discrepancy is detected, prior to further flight, 
replace the cargo compartment door hinges with new hinges in 
accordance with Part B of the Accomplishment Instructions of the 
service bulletin.
    (3) Remove the existing fasteners, repair, and replace the cargo 
compartment door hinges with new hinges in accordance with Part C of 
the Accomplishment Instructions of the service bulletin.
    (b) For airplanes having serial numbers 108 through 210 
inclusive: Prior to the accumulation of 36,000 total flight cycles, 
or within 30 days after the effective date of this AD, whichever 
occurs later, perform a one-time visual inspection to determine if 
rivets are installed in the key holes located on main frames 25 and 
27 of the fuselage, between stringers 14 and 15, in accordance with 
Avions de Transport Regional Service Bulletin ATR72-53-1013, 
Revision 3, dated January 22, 1999.
    (1) If all rivets are installed, no further action is required 
by paragraph (b) of this AD.
    (2) If any rivet is missing, prior to further flight, perform an 
eddy current inspection of the affected key holes to detect cracks, 
in accordance with the service bulletin.

[[Page 57605]]

    (i) If no crack is detected during the inspection required by 
paragraph (b)(2) of this AD, prior to further flight, install rivets 
in all affected key holes, in accordance with the service bulletin. 
If installation of rivets is not possible, 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).
    (ii) If any crack is detected during the inspection required by 
paragraph (b)(2) of this AD, 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).
    (c) For airplanes having serial numbers 108 through 207 
inclusive: Prior to the accumulation of 36,000 total flight cycles, 
or within 30 days after the effective date of this AD, whichever 
occurs later, perform a one-time visual inspection to determine if 
rivets are installed in the tooling and key holes located on the 
standard frames of the fuselage, in accordance with Avions de 
Transport Regional Service Bulletin ATR72-53-1019, Revision 3, dated 
January 22, 1999.
    (1) If all rivets are installed, no further action is required 
by paragraph (c) of this AD.
    (2) If any rivet is missing, prior to further flight, perform a 
visual inspection of the affected tooling and key holes to detect 
cracks, in accordance with the service bulletin.
    (i) If no crack is detected during the inspection required by 
paragraph (c)(2) of this AD, prior to further flight, install new 
rivets in all affected tooling and key holes, in accordance with the 
service bulletin.
    (ii) If any crack is detected during the inspection required by 
paragraph (c)(2) of this AD, 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).
    (d) For airplanes on which Aerospatiale Modification 03775 
(reference Avions de Transport Regional Service Bulletin ATR72-52-
1029, Revision 1, dated November 16, 1994) or Aerospatiale 
Modification 03776 (reference Avions de Transport Regional Service 
Bulletin ATR72-52-1033, dated April 28, 1995) has not been 
accomplished: Prior to the accumulation of 12,000 total flight 
cycles, or within 30 days after the effective date of this AD, 
whichever occurs later, perform an eddy current inspection to detect 
cracks in the plug door stop fittings of the forward and aft 
passenger and service doors, in accordance with Avions de Transport 
Regional Service Bulletin ATR72-52-1028, dated July 5, 1993.
    (1) If no crack is detected, repeat the eddy current inspection 
required by paragraph (d) of this AD thereafter at intervals not to 
exceed 6,000 flight cycles.
    (2) If any crack is detected, prior to further flight, replace 
the cracked stop fittings with new, improved fittings, in accordance 
with Avions de Transport Regional Service Bulletin ATR72-52-1033, 
dated April 28, 1995, or ATR72-52-1029, Revision 1, dated November 
16, 1994; as applicable. Accomplishment of the replacement 
constitutes terminating action for the repetitive inspection 
requirements of paragraph (d)(1) of this AD for that fitting.
    (e) For airplanes on which Aerospatiale Modification 03775 or 
Aerospatiale Modification 03776 has not been accomplished: Prior to 
the accumulation of 18,000 total flight cycles, or within 30 days 
after the effective date of this AD, whichever occurs later, replace 
the plug door stop fittings of the forward and aft passenger and 
service doors with new, improved fittings, in accordance with Avions 
de Transport Regional Service Bulletin ATR72-52-1033, dated April 
28, 1995; or ATR72-52-1029, Revision 1, dated November 16, 1994; as 
applicable. Accomplishment of the replacement constitutes 
terminating action for the repetitive inspection requirements of 
paragraph (d)(1) of this AD.
    (f) For airplanes on which Aerospatiale Modification 02986 
(reference Avions de Transport Regional Service Bulletin ATR72-53-
1021, Revision 1, dated February 20, 1995) has not been 
accomplished: Prior to the accumulation of 18,000 total flight 
cycles, or within 30 days after the effective date of this AD, 
whichever occurs later, perform a one-time eddy current inspection 
to detect cracks in the rivet holes of the door surround corners of 
the forward and aft passenger and service doors, in accordance with 
Avions de Transport Regional Service Bulletin ATR72-53-1021, 
Revision 1, dated February 20, 1995.
    (1) If no crack is detected during the inspection required by 
paragraph (f) of this AD, prior to further flight, modify the rivet 
holes, and replace the door surround corners with modified corners, 
in accordance with the service bulletin.
    (2) If any crack is detected during the inspection required by 
paragraph (f) of this AD, prior to further flight, repair and modify 
in accordance with a method approved by the Manager, International 
Branch, ANM-116; or the DGAC (or its delegated agent).
    (g) For airplanes on which Aerospatiale Modification 02397 
(reference Avions de Transport Regional Service Bulletin ATR72-53-
1014, Revision 2, dated October 15, 1992) has not been accomplished: 
Prior to the accumulation of 12,000 total flight cycles, or within 
30 days after the effective date of this AD, whichever occurs later, 
perform a one-time eddy current inspection to detect cracks of the 
rivet holes located on the left and right sides of external stringer 
4 at frames 24 and 28 of the fuselage, in accordance with Avions de 
Transport Regional Service Bulletin ATR72-53-1014, Revision 2, dated 
October 15, 1992.
    (1) If no crack is detected during the inspection required by 
paragraph (g) of this AD, prior to further flight, install 
reinforcement angles on the left and right sides of external 
stringer 4 at frames 24 and 28 of the fuselage, in accordance with 
the service bulletin.
    (2) If any crack is detected during the inspection required by 
paragraph (g) of this AD, 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).
    (h) For airplanes on which Aerospatiale Modification 03185 
(reference Avions de Transport Regional Service Bulletin ATR72-53-
1020, dated October 6, 1992) has not been accomplished: Prior to the 
accumulation of 12,000 total flight cycles, or within 30 days after 
the effective date of this AD, whichever occurs later, perform a 
one-time eddy current inspection to detect cracks of the rivet holes 
located on stringer 11 of frame 26 of the fuselage, in accordance 
with Avions de Transport Regional Service Bulletin ATR72-53-1020, 
dated October 6, 1992.
    (1) If no crack is detected during the inspection required by 
paragraph (h) of this AD, prior to further flight, install doublers 
and stringer clips on the left and right sides on stringer 11 of 
frame 26 of the fuselage, in accordance with the service bulletin.
    (2) If any crack is detected during the inspection required by 
paragraph (h) of this AD, 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).

    Note 2: Inspections and repairs accomplished prior to the 
effective date of this AD in accordance with Avions de Transport 
Regional Service Bulletins ATR72-53-1013, dated June 10, 1991, or 
Revision 1, dated June 12, 1992, or Revision 2, dated March 22, 
1993; ATR72-53-1019, dated May 13, 1993, or Revision 1, dated 
November 11, 1994, or Revision 2, dated October 15, 1996; ATR72-52-
1029, dated July 20, 1994; or ATR72-53-1014, Revision 1, dated June 
30, 1992; are considered acceptable for compliance with the 
applicable actions specified in this amendment.

Alternative Methods of Compliance

    (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, 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (j) Special flight permits may be issued in accordance with 
Secs. 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 4: The subject of this AD is addressed in French 
airworthiness directive 92-046-012(B)R4, dated November 5, 1997.

    Issued in Renton, Washington, on October 20, 1999.
N.B. Martenson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-27939 Filed 10-25-99; 8:45 am]
BILLING CODE 4915-13-U