AD 99-06-01

This amendment supersedes Airworthiness Directive (AD) 81-15-04 R1, which currently requires repetitively inspecting for cracks at the elevator outboard hinge attachment on the horizontal stabilizer rear spar on certain The New Piper Aircraft, Inc. (Piper) Models PA-31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 airplanes, and if cracks are found, incorporating a spar and hinge bracket assembly kit. This AD requires repetitively inspecting the horizontal rear spar in the area of the outboard hinge attachment and the outboard hinge attach bracket for cracks. When cracks are found or at a certain accumulation of time-in-service (TIS), this AD also requires modifying the horizontal stabilizer spar by incorporating an improved stabilizer spar and hinge bracket assembly kit that will terminate the repetitive inspections. This AD is prompted by several field reports of cracks found during routine inspections on airplanes already in compliance with AD 81-15-04 R1. The actions specified by this AD are intended to prevent failure of the horizontal stabilizer rear spar caused by cracks at the elevator outboard hinge attachment, which could result in loss of control of the airplane.

Final rule

99-06-01 THE NEW PIPER AIRCRAFT, INC.: Amendment 39-11065; Docket No. 97-CE-152-AD; Supersedes AD 81-15-04 R1, Amendment 39-4200.

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

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/operator must request approval for an alternative method of compliance in accordance with paragraph (f) 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: As indicated in the body of this AD, unless already accomplished.

To prevent failure of the horizontal stabilizer rear spar caused by cracks at the elevator outboard hinge attachment, which could result in loss of control of the airplane, accomplish the following:

(a) Within the next 100 hours time-in-service (TIS) after the effective date of this AD, inspect the horizontal stabilizer rear spar in the area of the outboard hinge attachment and the outboard hinge attach bracket for cracks in accordance with the INSTRUCTIONS section of Piper Service Bulletin (SB) No. 1007, dated September 30, 1997.

(b) If cracks are found in the horizontal stabilizer rear spar during the inspection required by paragraph (a) of this AD, prior to further flight, modify the horizontal stabilizer rear spar by incorporating Piper Kit No. 766-646. Accomplish this modification in accordance with the INSTRUCTIONS contained in Piper Kit No. 766-646, which is referenced in Piper SB No. 1007, dated September 30, 1997.

(c) If no cracks are found in the horizontal stabilizer rear spar during the inspection required by paragraph (a) of this AD, continue to inspect in accordance with paragraph (a) of this AD at intervals not to exceed 100 hours TIS. Upon the accumulation of 500 hours TIS after the effective date of this AD or when cracks are found, whichever occurs first, modify the horizontal stabilizer rear spar by incorporating Piper Kit No. 766-646. Accomplish this modification in accordance with the INSTRUCTIONS contained in Piper Kit No. 766-646, which is referenced in Piper SB No. 1007, dated September 30, 1997.

(d) Modifying the affected airplane by incorporating Piper Kit No. 766-646 is considered terminating action for the inspections required in paragraphs (a) and (c) of this AD.

(e) 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.

(f) 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 81-15-04 R1 are not considered approved as alternative methods of compliance for this AD.

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

(g) The inspections required by this AD shall be done in accordance with Piper Service Bulletin No. 1007, dated September 30, 1997. The modification required by this AD shall be done in accordance with the Instructions in Piper Kit No. 766-646, which is referenced in Piper Service Bulletin No. 1007, dated September 30, 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.

(h) This amendment supersedes AD 81-15-04 R1, Amendment 39-4200.

(i) This amendment becomes effective on April 20, 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 Model PA-31, PA-31-300, PA-31-325, PA-31-350, and PA-31P-350 airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on September 21, 1998 (63 FR 50174). The NPRM proposed to supersede AD 81-15-04 R1, Amendment 39-4200, which currently requires repetitively inspecting for cracks at the elevator outboard hinge attachment on the horizontal stabilizer rear spar, and if cracks are found, incorporating a spar and hinge bracket assembly kit. The NPRM proposed to require:

- Inspecting the horizontal stabilizer rear spar at the outboard hinge attachment and outboard hinge attach bracket for cracks;

- If no cracks are found, the NPRM proposed to require repetitively inspecting this area until cracks are found; and

- If cracks are found or upon the accumulation of 500 hours TIS, whichever occurs first, modify the horizontal stabilizer rear spar by incorporating Piper Kit No. 766-646. The incorporation of this kit will terminate the currently required repetitive inspections.

Accomplishment of the proposed inspections as specified in the NPRM would be in accordance with Piper Service Bulletin (SB) No. 1007, dated September 30, 1997. Accomplishment of the proposed modification as specified in the NPRM would be in accordance with the Instructions in Piper Kit No. 766-646, which is referenced in Piper SB No. 1007, dated September 30, 1997.

The NPRM was the result of several field reports of cracks found during routine inspections on airplanes already in compliance with AD 81-15-04 R1.

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 DeterminationAfter 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.

Differences Between the Service Information and This AD
The compliance time specified in Piper Service Bulletin No. 1007, dated September 30, 1997, is different than the compliance time in this AD. The FAA is not using the 50 hours time-in-service (TIS) as the initial and repetitive inspection times, as specified in the service bulletin. Fifty hours TIS or less is normally reserved for urgent safety of flight conditions, and this AD is not considered an urgent safety of flight condition. Based on engineering judgment and the service history received from the field, the FAA is utilizing an initial and repetitive inspection time of 100 hours TIS in order to allow operators a reasonable amount of time to accomplish this action.

Cost Impact
The FAA estimates that 1,739 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 11 workhours per airplane to accomplish the actions in this AD, and that the average labor rate is approximately $60 an hour. Parts cost approximately $478 per airplane. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $1,978,982, or $1,138 per airplane.

This cost estimate does not take into account the number of repetitive inspections that may be incurred over the life of each airplane, and is based on the presumption that no owner/operator of the affected aircraft has accomplished the replacement.

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, 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 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 removing Airworthiness Directive (AD) 81-15-04 R1, Amendment 39-4200, and by adding a new AD to read as follows: