Airworthiness directives: New Piper Aircraft, Inc.,

 
CONTENT

[Federal Register: November 25, 1998 (Volume 63, Number 227)]

[Proposed Rules]

[Page 65147-65149]

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

[DOCID:fr25no98-28]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-32-AD]

RIN 2120-AA64

Airworthiness Directives; The New Piper Aircraft, Inc. Models PA- 31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes to adopt a new airworthiness directive (AD) that would apply to certain The New Piper Aircraft, Inc. (Piper) Models PA-31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 airplanes. The proposed AD would require installing access holes for the inspection of the elevator spar; inspecting the elevator ice protection boots for looseness and reinstalling or replacing the elevator ice protection boots if looseness is found. The proposed AD also requires repetitively inspecting the elevator spars for cracks, and replacing the elevators or elevator spar assemblies with parts of improved design either at a certain time period or when cracks are found, whichever occurs first. The proposed AD is the result of reports of cracks developing in the elevator spar inboard of the outboard hinge location on the affected airplanes. The actions specified by the proposed AD are intended to prevent failure of the elevator spar caused by fatigue cracking, which could result in reduced airplane controllability.

DATES: Comments must be received on or before January 27, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 97-CE-32-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.

Service information that applies to the proposed AD may be obtained from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive, Vero Beach, Florida 32960. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: William 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 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. 97-CE-32-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. 97-CE-32-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

The FAA has received several reports of cracks in the elevator spar inboard of the outboard hinge attachment location on Piper Models PA- 31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 airplanes. Initiation of these cracks is at the end rivets in the reinforcement doubler on the aft surface of the spar. These cracks are occurring at the end row of rivets that attach the spar and reinforcement doubler. The FAA has also received reports of cracks at the outboard end of the spar.

Poorly installed or maintained ice protection boots on the affected airplanes may aggravate the occurrence and growth of these cracks. If these ice protection boots become loose, they may set up a vibration and promote fatigue cracking of the elevator spar.

These conditions, if not corrected in a timely manner, could result in failure of the elevator spar with reduced airplane controllability.

Relevant Service Information

Piper has issued Service Bulletin No. 998A, dated August 4, 1997, which specifies procedures for installing access holes for the inspection of the elevator spar; inspecting the elevator ice protection boots for looseness and reinstalling or replacing the elevator ice protection boots if looseness is found; and repetitively inspecting the elevator spars for cracks.

The FAA's Determination

After examining the circumstances and reviewing all available information related to the incidents described above,

[[Page 65148]]

including the referenced service information, the FAA has determined that AD action should be taken to prevent failure of the elevator spar caused by fatigue cracking, which could result in reduced airplane controllability.

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-31, PA-31-300, PA-31-325, PA- 31-350, and PA-31P-350 airplanes of the same type design, the FAA is proposing AD action. The proposed AD would require installing access holes for the inspection of the elevator spar; inspecting the elevator ice protection boots for looseness and reinstalling or replacing the elevator ice protection boots if looseness is found. The proposed AD also requires repetitively inspecting the elevator spars for cracks, and replacing the elevators or elevator spar assemblies with parts of improved design either at a certain time period or when cracks are found, whichever occurs first.

Accomplishment of the proposed inspection access holes installation, inspections, and elevator ice protection boots reinstallation or replacement is required in accordance with Piper Service Bulletin No. 998A, dated August 4, 1997.

Accomplishment of the installation of the improved design elevators or elevator spar assemblies is required in accordance with the maintenance manual.

The FAA's Aging Commuter Aircraft Policy

The actions proposed in this NPRM are consistent with the FAA's aging commuter aircraft policy, which briefly states that, when a modification exists that could eliminate or reduce the number of required critical inspections, the modification should be incorporated. This policy is based on the FAA's determination that reliance on critical repetitive inspections on airplanes utilized in commuter service carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections. In determining what inspections are critical, the FAA considers (1) the safety consequences of the airplane if the known problem is not detected by the inspection; (2) the reliability of the inspection such as the probability of not detecting the known problem; (3) whether the inspection area is difficult to access; and (4) the possibility of damage to an adjacent structure as a result of the problem.

The alternative to replacing the elevators or elevator spar assemblies with ones of improved design would be to repetitively inspect this area for the life of the airplane.

Cost Impact

The FAA estimates that 1,739 airplanes in the U.S. registry would be affected by the proposed AD.

The proposed inspection holes installation and inspections would take approximately 2 workhours per airplane to accomplish with an average labor rate of approximately $60 an hour. Parts cost approximately $26 per airplane. Based on these figures, the total cost impact of the proposed inspection access holes installation and inspections on U.S. operators is estimated to be $253,894, or $146 per airplane.

The proposed elevator spar assembly replacements would take approximately 36 workhours per airplane to accomplish with an average labor rate of approximately $60 an hour. Parts cost approximately $600 per airplane ($300 per elevator spar assembly with 2 elevator spar assemblies per airplane). Based on these figures, the total cost impact of the proposed elevator spar assembly replacement on U.S. operators is estimated to be $4,799,640, or $2,760 per airplane.

According to Piper, numerous airplanes already have complied with the proposed initial inspection requirements of this NPRM, specifically most of the Model PA-31-350 airplanes since many of these are used in commuter service.

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 adding a new airworthiness directive (AD) to read as follows:

    The New Piper Aircraft, Inc.: Docket No. 97-CE-32-AD.

    Applicability: The following airplane model and serial numbers, certificated in any category, that are not equipped with the applicable improved design elevators or elevator spar assemblies specified in the ``Replacement Elevator P/N'' and ``Replace Spar P/ N'' columns of the ``Material Required Table'' on page 4 of Piper Service Bulletin No. 998A, dated August 4, 1997:

    Models

    Serial numbers

    PA-31, PA-31-300, and PA-31-325............... 31-2 through 31-8312019. PA-31-350..................................... 31-5001 through 31-8553002. PA-31P-350.................................... 31P-8414001 through 31P-8414050.

    [[Page 65149]]

    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 (g) 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 in the body of this AD, unless already accomplished.

    To prevent failure of the elevator spar caused by fatigue cracking, which could result in reduced airplane controllability, accomplish the following:

    (a) Upon accumulating 2,500 hours time-in-service (TIS) on each elevator spar assembly or within the next 100 hours TIS after the effective date of this AD, whichever occurs later, accomplish the following in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 998A, dated August 4, 1997:

    (1) Install access holes for the inspection of the elevator spar;

    (2) Inspect the elevator spars for cracks; and

    (3) Inspect the elevator ice protection boots for looseness.

    (b) If the elevator ice protection boots are found loose during the inspection required by paragraph (a)(3) of this AD, prior to further flight, reinstall or replace the elevator ice protection boots in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 998A, dated August 4, 1997.

    (c) If no cracks are found in the elevator spars during the inspection required by paragraph (a)(2) of this AD, reinspect the elevator spars for cracks at intervals not to exceed 100 hours TIS, provided no cracks are found (if cracks are found, refer to paragraphs (d) and (d)(1) of this AD).

    (d) At whichever of the compliance times presented in paragraphs (d)(1) and (d)(2) of this AD that occurs first, replace each elevator or elevator spar assembly with a part of improved design as specified in the ``Replacement Elevator P/N'' and ``Replace Spar P/ N'' columns of the ``Material Required Table'' on page 4 of Piper Service Bulletin No. 998A, dated August 4, 1997. Accomplish these replacements in accordance with the applicable maintenance manual.

    (1) Prior to further flight on any elevator spar assembly where any cracks are found during the initial inspection required by paragraph (a)(2) of this AD or any repetitive inspection required by paragraph (c) of this AD; or

    (2) Within 1,000 hours TIS after the initial inspection required by paragraph (a)(2) of this AD.

    (e) Replacing both the left and right elevators or elevator spar assemblies with parts of improved design as specified in the ``Replacement Elevator P/N'' and ``Replace Spar P/N'' columns of the ``Material Required Table'' on page 4 of Piper Service Bulletin No. 998A, dated August 4, 1997, is considered terminating action for the repetitive inspection requirement of this AD.

    (1) This action may be accomplished at any time to terminate the repetitive inspections, but must be accomplished prior to further flight on any elevator spar found cracked or within 1,000 hours TIS after the initial inspection, whichever occurs first.

    (2) If one elevator spar assembly is replaced prior to further flight when a crack is found, the other elevator spar assembly must still be repetitively inspected every 100 hours TIS until replacement at 1,000 hours TIS after the initial inspection or when cracks are found, whichever occurs later.

    (f) 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.

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

    Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

    (h) All persons affected by this directive may obtain copies of the document referred to herein upon request to The New Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960; or may examine this document at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on November 17, 1998. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service.

    [FR Doc. 98-31436Filed11-24-98; 8:45 am]

    BILLING CODE 4910-13-U