AD 99-12-05

This amendment adopts a new airworthiness directive (AD) that applies 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. This AD requires 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. This 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. This 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 this AD are intended to prevent failure of the elevator spar caused by fatigue cracking, which could result in reduced airplane controllability.

Final rule

99-12-05 THE NEW PIPER AIRCRAFT, INC.: Amendment 39-11189; 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

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/operatormust 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 elevatorspar;

(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 first.

(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) The installations, inspections, and replacements required by this AD shall be done in accordance with Piper Service Bulletin No. 998A, dated August 4, 1997. 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 The New Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

(i) This amendment becomes effective on July 23, 1999.

Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Piper Models PA-31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 was published in the Federal Register as a notice of proposed rulemaking (NPRM) on November 25, 1998 (63 FR 65147). The NPRM proposed to 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 NPRM also proposed to require 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 as specified in the NPRM 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 as specified in the NPRM is required in accordance with the maintenance manual.

The NPRM was the result of reports of cracks developing in the elevator spar inboard of the outboard hinge location on the affected airplanes.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

The FAA's Aging Commuter Aircraft Policy
The actions required in this AD 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 will be affected by this AD.

The inspection holes installation and initial inspections will 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 inspection access holes installation and initial inspections on U.S. operators is estimated to be $253,894, or $146 per airplane.

These figures only take into account the costs of the initial inspection and do not take into account the costs of repetitive inspections. The FAA has no way of determining the number of repetitive inspections an owner/operator will incur over the life of the airplane before the replacement becomes mandatory.

The elevator spar assembly replacements will 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 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 initial inspection requirements of this AD, specifically most of the Model PA-31-350 airplanes since many of these are used in commuter service.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, oron the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does 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) 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 final 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, 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 a new airworthiness directive (AD) to read as follows: