Airworthiness directives: New Piper Aircraft, Inc.,

[Federal Register: May 22, 1998 (Volume 63, Number 99)]

[Proposed Rules]

[Page 28294-28299]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr22my98-22]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-09-AD]

RIN 2120-AA64

Airworthiness Directives; The New Piper Aircraft, Inc. PA-24, PA- 28R, PA-30, PA-32R, PA-34, and PA-39 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes to revise Airworthiness Directive (AD) 97-01-01, which currently requires repetitively inspecting the main gear sidebrace studs for cracks on The New Piper Aircraft, Inc. (Piper) Models PA-24, PA-28R, PA-30, PA-32R, PA-34, and PA-39 series airplanes, and replacing any main gear sidebrace stud found cracked. The Federal Aviation Administration (FAA) has approved certain alternative methods of compliance (AMOC) for AD 97-01-01, and has determined that these AMOC's should be incorporated into the AD. The proposed AD would retain all the actions of AD 97-01-01, and would incorporate certain AMOC's as a way of accomplishing the actions specified in AD 97-01-01. The actions specified by the proposed AD are intended to prevent a main landing gear collapse caused by main gear sidebrace stud cracks, which could result in loss of control of the airplane during landing operations.

DATES: Comments must be received on or before July 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 96-CE-09-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

Information that applies to the proposed AD may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. William O. Herderich, Aerospace Engineer, FAA, Atlanta Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone: (770) 703-6084; facsimile: (770) 703-6097.

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 should 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

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interested persons. A report that summarizes each FAA-public contact concerned with the substance of this proposal will be filedin 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 No. 96-CE-09-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, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 96-CE-09-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

AD 97-01-01, Amendment 39-9872 (62 FR 10, January 2, 1997), currently requires repetitively inspecting the main gear sidebrace studs for cracks on Piper Models PA-24, PA-28R, PA-30, PA-32R, PA-34, and PA-39 series airplanes, and replacing any main gear sidebrace stud found cracked. The actions specified by AD 97-01-01 are intended to prevent a main landing gear collapse caused by main gear sidebrace stud cracks, which could result in loss of control of the airplane during landing operations.

Actions Since Issuance of Previous Rule

Since issuance of AD 97-01-01, the FAA has approved alternative methods of compliance for modifying the existing bracket assembly as terminating action for the repetitive inspection requirement of that AD.

The FAA's Determination

After examining the circumstances and reviewing all available information related to the subject described above, the FAA has determined that (1) the alternative methods of compliance approved for modifying the existing bracket assembly should be made available as an option of complying with the current AD; and (2) AD action should be taken to prevent a main landing gear collapse caused by main gear sidebrace stud cracks, which could result in loss of control of the airplane during landing operations.

Explanation of the Provisions of the Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop in other Piper Models PA-24, PA-28R, PA-30, PA-32R, PA-34, and PA-39 series airplanes of the same type design, the FAA is proposing to revise AD 97-01-01. The proposed AD would retain all the actions of AD 97-01-01, and would incorporate alternative methods of compliance for modifying the existing bracket assembly, as terminating action for the repetitive inspection requirement of that AD.

Cost Impact

The cost impact of the proposed AD would be the same as is currently required by AD 97-01-01. As a courtesy, the FAA is reprinting that cost information in the following paragraphs.

The FAA estimates that 13,200 airplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 5 workhours per airplane to accomplish the proposed action, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the proposed inspection on U.S. operators is estimated to be $3,960,000. This figure represents the total cost of the proposed initial inspection, and does not reflect costs for any of the proposed repetitive inspections or possible replacements. The FAA has no way of determining how many main gear side brace studs may need replacement or how many repetitive inspections each owner/operator may incur over the life of the airplane.

In addition, the proposed AD would require the same inspections required by AD 95-20-07 (which was superseded by AD 97-01-01). The only difference between the proposed AD and AD 95-20-07 is the addition of an inspection-terminating modification option and the elimination of (from the ``Applicability'' section of the AD) certain airplanes that incorporate a certain main side brace stud assembly. The proposed AD would also not provide any additional cost impacts over that already required by AD 95-20-07.

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 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) 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 has been placed 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 Airworthiness Directive 97-01-01, Amendment 39-9872 (62 FR 10, January 2, 1997), and by adding a new AD to read as follows:

   The New Piper Aircraft, Inc.: Docket No. 96-CE-09-AD; Revises AD 97- 01-01, Amendment 39-9872.

   Applicability: The following airplane models and serial numbers, certificated in any category:

1. All serial numbers of Models PA-24, PA-24-250, PA-24-260, PA- 24-400, PA-30, and PA-39 airplanes;

2. The following model and serial number airplanes that are not equipped with a Piper part number (P/N) 78717-02 (or FAA-approved equivalent part number) main gear sidebrace stud in both right and left main gear sidebrace bracket assemblies:

   Model

   Serial Nos.

   PA-28R-180............................ 28R-30002 through 28R-31135, and 28R-7130001 through 28R- 7130013.

   PA-28R-200............................ 28R-35001 through 28R-35820, and 28R-7135001 through 28R- 7635539.

   PA-28R-201............................ 28R-7737002 through 28R-7737096. PA-28R-201T........................... 28R-7703001 through 28R-7703239. PA-32R-300............................ 32R-7680001 through 32R-7780444.

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   PA-34-200............................. All serial numbers.

   PA-34-200T............................ 34-7570001 through 34-7770372.

   Note 1: P/N 78717-02 sidebrace stud was installed at manufacture on Piper Model PA-34-200T airplanes, serial numbers 34-7670325 through 34-7770372.

   Note 2: 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 (e) 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 initially as follows, and thereafter as specified in the body of this AD:

1. For the affected Models PA-28R-180, PA-28R-200, PA-28R-201, PA-28R-201T, PA-32R-300, PA-34-200, and PA-34-200T airplanes: Within the next 100 hours time-in-service (TIS) after the effective date of this AD; or, if the main gear sidebrace stud has already been inspected or replaced as specified in this AD, within 500 hours TIS after the last inspection or replacement; whichever occurs later.

2. For the affected Models PA-24, PA-24-250, PA-24-260, PA-24- 400, PA-30, and PA-39 airplanes: Within the next 100 hours TIS after the effective date of this AD; or, if the main gear sidebrace stud has already been inspected or replaced as specified in this AD, within 1,000 hours TIS after the last inspection or replacement; whichever occurs later.

   To prevent main landing gear (MLG) collapse caused by main gear sidebrace stud cracks, which could result in loss of control of the airplane during landing operations, accomplish the following:

   Note 3: The paragraph structure of this AD is as follows:

   Level 1: (a), (b), (c), etc. Level 2: (1), (2), (3), etc. Level 3: (i), (ii), (iii), etc. Level 4: (A), (B), (C), etc.

   Level 2, Level 3, and Level 4 structures are designations of the Level 1 paragraph they immediately follow.

   (a) Remove both the left and right main gear sidebrace studs from the airplane in accordance with the instructions contained in the Landing Gear section of the maintenance manual, and inspect each main gear sidebrace stud for cracks, using Type I (fluorescent) liquid penetrant or magnetic particle inspection methods. Figure 1 of this AD depicts the area of the sidebrace stud shank where the sidebrace stud is to be inspected.

   Note 4: All affected Models PA-24 and PA-24-250 airplanes were equipped at manufacture with P/N 20829-00 main gear sidebrace studs. All affected Models PA-24-260, PA-24-400, PA-30, and PA-39 airplanes were equipped at manufacture with P/N 22512-00 main gear sidebrace studs. The Appendix included with this AD contains information on determining the P/N of the bracket assembly (which contains the main gear side brace stud) on the affected PA-28R, PA-32R, and PA-34 series airplanes.

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   (1) For any main gear sidebrace stud found cracked, prior to further flight, replace the cracked stud with an FAA-approved serviceable part (part numbers referenced in the table in paragraph (b) of this AD or FAA-approved equivalent part number) in accordance with the instructions contained in the Landing Gear section of the applicable maintenance manual, and accomplish one of the following, as applicable:

   (i) Reinspect (and replace as necessary) as specified in paragraph (b) of this AD; or

   (ii) For the affected Models PA-28R-180, PA-28R-200, PA-28R-201, PA-28R-201T, PA-32R-300, PA-34-200, and PA-34-200T airplanes, the 9/ 16-inch main gear sidebrace studs (P/N 95299-00, 95299-02, or P/N 67543, as applicable) are no longer manufactured. Install a new main gear sidebrace stud bracket assembly, P/N 95643-06, P/N 95643-07, P/ N 95643-08, or P/N 95643-09, as applicable. No repetitive inspections will be required by this AD for these affected airplane models when this bracket assembly is installed; or

   (iii) For the affected Models PA-28R-180, PA-28R-200, PA-28R- 201, PA-28R-201T, PA-32R-300, PA-34-200, and PA-34-200T airplanes, ream the existing two-piece bushings to an inside diameter of .624- inch to .625-inch, chamfer the head side of the bushing to accommodate the radius in the shank of the main gear sidebrace stud, and install the \5/8\-inch stud, P/N 78717-02. No repetitive inspections will be required by this AD when this action is accomplished. If the bushings cannot be reamed while installed in the bracket (i.e., the bushings are loose), then install a main gear sidebrace bracket assembly, P/N 95643-06, P/N 95643-07, P/N 95643- 08, or P/N 95643-09, as applicable. Models PA-28R-180 and PA-28R-200 with serial numbers as specified in the Appendix to this AD may be equipped with a bracket casting identified with casting number 67073-2 or 67073-3 and may require the following modification to P/N 78717-02 for proper installation:

   (A) Reduce the length of the stud to 1.688 ‹plus-minus› 0.15 inches;

   (B) Add additional rolled threads to 1.125 ‹plus-minus› .015 inches from the flange. Note that the stud is heat treated to 180 to 200 ksi; and

   (C) Drill an additional roll pin hole 90 degrees to the existing hole, and approximately 1.480 inches from the flange.

   (iv) No repetitive inspections will be required by this AD when a P/N 78717-02 (or FAA-approved equivalent part number) main gear sidebrace stud is installed in the existing bracket assembly or when a bracket assembly, P/N 95643-07 (or FAA-approved equivalent part number), P/N 95643-08 (or FAA-approved equivalent part number), or P/N95643-09 (or FAA-approved equivalent part number), as applicable, is installed.

   (2) For any main gear sidebrace stud not found cracked, prior to further flight, reinstall the uncracked stud in accordance with the instructions contained in the Landing Gear section of the applicable maintenance manual, and reinspect and replace (as necessary) as specified in paragraph (b) of this AD.

   (b) Reinspect both the left and right main gear sidebrace studs, using Type I (fluorescent) liquid penetrant or magnetic particle inspection methods. Replace any cracked stud or reinstall any uncracked stud as specified in paragraphs (a)(1) and (a)(2) of this AD, respectively:

   TIS

   inspection Model airplanes

   Part number installed

   interval

   installed on (hours)

   20829-00 (Piper parts) or FAA-

   1,000 PA-24 and PA-24-250.

   approved equivalent part number.

   22512-00 (Piper parts) or FAA-

   1,000 PA-24-260, PA-24-400, PA- approved equivalent part number.

   30, and PA-39.

   95299-00 or 95299-02 (Piper

   500 PA-28R-180 and PA-28R- parts) or FAA-approved

   200 not equipped with equivalent part number.

   casting number 67073-2 or 67073-3, PA-28R-201, PA-28R-201T, PA-32R- 300, PA-34-200, and PA- 34-200T.

   67543 (Piper parts) or FAA-

   500 PA-28R-180 and PA-28R- approved equivalent part number.

   200 equipped with casting number 67073-02 or 67073-03.

   Note 5: Accomplishing the actions of this AD does not affect the requirements of AD 77-13-21, Amendment 39-3093. The tolerance inspection requirements of that AD still apply for Piper PA-24, PA- 30, and PA-39 series airplanes.

   (c) Owners/operators of the affected Models PA-28R-180, PA-28R- 200, PA-28R-201, PA-28R-201T, PA-32R-300, PA-34-200, and PA-34-200T airplanes may accomplish one of the following at any time to terminate the repetitive inspection requirement of this AD:

   (1) Install a main gear sidebrace bracket assembly, P/N 95643-06 (or FAA-approved equivalent part number), P/N 95643-07 (or FAA- approved equivalent part number), P/N 95643-08 (or FAA-approved equivalent part number), or P/N 95643-09 (or FAA-approved equivalent part number), as applicable, which contains the 5/8-inch diameter main gear sidebrace stud, P/N 78717-02 (or FAA-approved equivalent part number), and the one-piece bushing, P/N 67026-12 (or FAA- approved equivalent part number). Accomplish these installations in accordance with the instructions contained in the Landing Gear section of the applicable maintenance manual; or

   (2) Ream the existing two-piece bushings to an inside diameter of .624-inch to .625-inch, chamfer the head side of the bushing to accommodate the radius in the shank of the main gear sidebrace stud, and install the 5/8-inch stud, P/N 78717-02 (or FAA-approved equivalent part number). No repetitive inspections will be required by this AD when this action is accomplished. If the bushings cannot be reamed while installed in the bracket (i.e., the bushings are loose), then install a main gear sidebrace bracket assembly, P/N 95643-06 (or FAA-approved equivalent part number), P/N 95643-07 (or FAA-approved equivalent part number), P/N 95643-08 (or FAA-approved equivalent part number), or P/N 95643-09 (or FAA-approved equivalent part number), as applicable. Models PA-28R-180 and PA-28R-200 with serial numbers as specified in the Appendix to this AD may be equipped with a bracket casting identified with casting number 67073-2 or 67073-3 and may require the following modification to P/N 78717-02 (or FAA-approved equivalent part number) for proper installation:

   (i) Reduce the length of the stud to 1.688 ‹plus-minus› 0.15 inches;

   (ii) Add additional rolled threads to 1.125 ‹plus-minus› .015 inches from the flange. Note that the stud is heat treated to 180 to 200 ksi; and

   (iii) Drill an additional roll pin hole 90 degrees to the existing hole, and approximately 1.480 inches from the flange.

   (d) 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.

   (e) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Atlanta Aircraft Certification Office (ACO), One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349.

   (1) The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

   (2) Alternative methods of compliance approved in accordance with AD 97-01-01, Amendment 39-9872 (revised by this action), or AD 95-20-07, Amendment 39-9386 (superseded by AD 97-01-01), are considered approved as alternative methods of compliance with this AD.

   Note 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

   (f) Information related to this AD may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri.

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   (g) This amendment revises AD 97-01-01, Amendment 39-9872, which superseded AD 95-20-07, Amendment 39-9386.

   Appendix to Docket No. 96-CE-09-AD Information to Determine Main Gear Sidebrace Stud Assembly Part Number (P/N)

   --The P/N 95643-00/-01/-02/-03 bracket assembly contains the 9/16- inch diameter main gear sidebrace stud, P/N 95299-00/-02, and a two- piece bushing, P/N 67026-6. --The P/N 95643-06/-07/-08/-09 bracket assembly contains the 5/8- inch diameter main gear sidebrace stud, P/N 78717-02, and a one- piece bushing, P/N 67026-12. --Both the one-piece and the two-piece bushing have a visible portion of the bushing flange, i.e., bushing shoulder. --Whether a one-piece or two-piece bushing is installed may be determined by measuring the outside diameter of the bushing flange with a micrometer (jaws of the caliper must be 3/32-inch or less). The two-piece bushing will have an outside diameter of 1.00 inch and the one-piece bushing will have an outside diameter of 1.128 to 1.130 inches. This measurement is not valid for the following airplanes:

   Model

   Serial Nos.

   PA-28R-180............................ 28R-30004 through 28-31270. PA-28R-200............................ 28R-35001 through 28R-35820, and 28R-7135001 through 28R- 7135062.

   The main gear sidebrace studs on these airplanes will require removal to determine the P/N installed.

   --The one-piece bushing contains a visible chamfer in the center of the bushing, and the chamfer in the two-piece bushing is not visible when the stud is installed. --If P/N 95643-00/-01/-02/-03 bracket assembly is installed or the above information cannot be utilized, the main gear sidebrace stud will need to be removed from the bracket to determine the shank diameter and main gear sidebrace stud P/N. --P/N 95299-00 and P/N 95299-02 main gear sidebrace studs are 9/16- inch in diameter. --P/N 78717-00 main gear sidebrace studs are 5/8-inch in diameter. --P/N 95643-00/-01/-02/-03 bracket assembly may have been modified to accommodate the 5/8-inch diameter main gear sidebrace stud, P/N 78717-02. --The embossed number of 95363 on the bracket forging is not the bracket assembly P/N. --The bracket assemblies identified with casting number 67073-2 or 67073-3 contain a 9/16-inch diameter main gear sidebrace stud, P/N 67543, and two-piece bushing, P/N 67026-2 and 67026-3. --Model PA-28R-180 airplanes, serial numbers 28R-30004 through 28R- 31270; and Model PA-28R-200 airplanes, serial numbers 28R-35001 through 28R-35820 and 28R-7135001 through 28R-7135062, are equipped from the factory with bracket assemblies identified with casting number 67073-2 and 67073-3. --P/N 67543 main gear sidebrace studs are 9/16-inch in diameter.

   Issued in Kansas City, Missouri, on May 14, 1998. Michael Gallagher, Small Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 98-13656Filed5-21-98; 8:45 am]

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