00-4338. Airworthiness Directives; Aerospatiale Model ATR72 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to certain Aerospatiale Model ATR72 series airplanes, that requires initial and repetitive inspections to detect fatigue cracking in certain areas of the fuselage, and corrective actions, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this 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:

Effective April 3, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 3, 2000.

ADDRESSES:

The service information referenced in this AD may be obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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 [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Aerospatiale Model ATR72 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on October 26, 1999 (64 FR 57602). That action proposed to require initial and repetitive inspections to detect fatigue cracking in certain areas of the fuselage, and corrective actions, if necessary.

Comments Received

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Approved Repairs

One commenter, an operator, expresses concern that paragraphs (c) and (d)(2)(ii) of the proposed AD mandate that any repairs, previously conducted through Aerospatiale, now must be approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Direction Generale de l'Aviation Civile (DGAC) (or its delegated agent). The commenter is concerned that, if the only resources for repair approvals are those mentioned here, any repair approval process will not be responsive on a timely basis. The commenter states that notification to the Manager, ANM-116, of damage found and the repair method used, following embodiment, would be more appropriate.

The FAA infers that the commenter is requesting that the AD be revised to allow repair approvals through Aerospatiale, with subsequent notification to the Manager, ANM-116. The FAA does not concur. To specify within an AD that repairs are to be accomplished in accordance with the manufacturer would be delegating the FAA's rulemaking authority to the manufacturer. Since the referenced service information does not provide appropriate repair procedures, the FAA must require that operators accomplish necessary repairs in accordance with a method approved by the FAA or the DGAC (or its delegated agent). The FAA notes that, if Aerospatiale has been designated by the DGAC as a delegated agent for repair approvals, such approvals by Aerospatiale would be acceptable for compliance with this AD. No change to the AD is necessary.

Prior Repairs

The same commenter notes that there should be some consideration for airplanes on which the modification has already been accomplished with some form of repair (prior to the effective date of the AD). As written, the AD would require that any such repair be “reapproved” by the FAA or DGAC.

The FAA does not concur. As noted in the FAA's response to the previous comment, repairs approved by Aerospatiale may be acceptable for compliance with this AD, if Aerospatiale is a delegated agent of the DGAC for such repairs. If this is the case, no “reapproval” is necessary, since such approved repairs would be acceptable for compliance with the requirements of this AD. Further, sufficient time is provided prior to the compliance thresholds of this AD to allow operators to determine if approvals must be obtained for previously accomplished repairs, and to obtain such approvals, if necessary. No change to the AD is necessary.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

The FAA estimates that 39 airplanes of U.S. registry will be affected by this AD.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1018 (14 U.S.-registered airplanes), it will take approximately 250 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Required parts will cost approximately $9,880 per airplane. Based on these figures, the cost impact of these actions required 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 will take approximately 3 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 will take approximately 100 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 will take approximately 5 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 will take approximately 145 work hours per airplane to accomplish the required door stop fitting replacement, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the stop fittings replacement required by this AD on 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 will take approximately 30 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 will take approximately 8 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 will take approximately 6 work hours per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions required 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 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 adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) Is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

§ 39.13

[Amended]

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

2000-04-13 Aerospatiale: Amendment 39-11596. Docket 98-NM-240-AD.

Applicability: Model ATR72 series airplanes, certificated in any category; listed in the following Avions de Transport Regional (ATR) 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:

Inspections and Corrective Actions

(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.

(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.

Special Flight Permits

(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.

Incorporation by Reference

(k) Except as required by paragraphs (a)(2)(i), (b)(2)(i), (b)(2)(ii), (c)(2)(ii), (f)(2), (g)(2), and (h)(2) of this AD, the actions shall be done in accordance with the following Avions de Transport Regional service bulletins, as applicable:

Service bulletin referenced and date	Page No.	Revision level shown on page	Date shown on page
ATR72-52-1018, May 18, 1995	1-116	Original	May 18, 1995.
ATR72-53-1013, Revision 3, January 22, 1999	1-4, 7 5, 8-10 6, 11	3 1 Original	January 22, 1999. June 12, 1992. June 10, 1991.
ATR72-53-1019, Revision 3, January 22, 1999	1-4 5, 6, 9-14, 16, 17 7, 8, 15	3 1 Original	January 22, 1999. November 11, 1994. May 13, 1993.
ATR72-52-1028, July 5, 1993	1-21	Original	July 5, 1993.
ATR72-52-1033, April 28, 1995	1-41	Original	April 28, 1995.
ATR72-52-1029, Revision 1, November 16, 1994	1, 8-14, 33, 34 2-7, 15-32, 35-50	1 Original	November 16, 1994. July 20, 1994.
ATR72-53-1021, Revision 1, February 20, 1995	1, 3, 5, 8, 11, 35, 36 2, 4, 6, 7, 9, 10, 12-34	1 Original	February 20, 1995. July 8, 1993.
ATR72-53-1014, Revision 2, October 15, 1992	1, 9-11, 15 2-8, 12-14	2 1	October 15, 1992. June 30, 1992.
ATR72-53-1020, October 6, 1992	1-15	Original	October 6, 1992.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 4:

The subject of this AD is addressed in French airworthiness directive 92-046-012(B)R4, dated November 5, 1997.

(l) This amendment becomes effective on April 3, 2000.

Issued in Renton, Washington, on February 17, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.