AD 96-21-03

This amendment adopts a new airworthiness directive (AD) that applies to The New Piper Aircraft, Inc. (Piper) PA31, PA31P, PA31T, and PA42 series airplanes. This action requires inspecting for cracks beneath and in the area of the inboard aileron hinge bracket on the aileron spar and rib using dye penetrant methods, replacing any cracked aileron spar or rib, and replacing the inboard aileron hinge bracket with a hinge bracket of improved design. Several reports of cracks in the vicinity of the inboard aileron hinge bracket, aileron spar, and aileron rib prompted this proposed action. The actions specified by the proposed AD are intended to prevent structural failure of the aileron caused by cracks in the area of the inboard aileron hinge bracket, which, if not detected and corrected, could result in loss of control of the airplane.

Final rule

96-21-03 THE NEW PIPER AIRCRAFT, INC.: Amendment 39-9780; Docket No. 95-CE- 84-AD.

Applicability: The following airplane models and serial numbers that are not equipped with part number (P/N) 74461-02 (left) and P/N 74461-03 (right) inboard aileron hinge brackets, certificated in any category:

Models
Serial Numbers

(The following aircraft should reference Piper Service Bulletin No. 974, dated October 19, 1994)
PA31, PA31-300, and PA31-325
31-2 through 31-8312019
PA31-350
31-5001 through 31-8553002
PA31P-350
31P-8414001 through 31P-8414050
PA31T3
31T-8275001 through 31T-8475001, and 31T-5575001

Models
Serial Numbers

(The following aircraft should reference Piper Service Bulletin No. 967, dated January 24, 1994)
PA31P
31P-1 through 31P-7730012, and 31P-03
PA31T
31T-7400002 through 31T-7400009, and
31T-7520001 through 31T-8120104
PA31T1
31T-7804001 through 31T-8304003, and 31T-1104004 through 31T-1104017
PA31T2
31T-8166001 through 31T-8166076, and
31T-1166001 through 31T-1166008
PA42
42-7800001 through 42-7800004, and
42-8001001 through 42-8001106
PA42-720
42-8301001, 42-8301002, 42-5501003 through 42-5501023, 42-5501025 through 42-5501027,
42-5501029 through 42-5501031, 42-5501033, and
42-5501039 through 42-5501059
PA42-720R
42-5501024, 42-5501028, 42-5501032, and
42-5501034 through 42-5501038
PA42-1000
42-5527002 through 42-5527044

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 (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: Upon the accumulation of 3,000 hours time-in-service (TIS), or within the next 100 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished.

NOTE 2: 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 2 and Level 3 structures are designations of the Level 1 paragraph they immediately follow.

To prevent structural failure of the aileron caused by cracks in the area of the inboard aileron hinge bracket, which, if not detected and corrected, could result in loss of control of the airplane, accomplish the following:

(a) Inspect (using dye penetrant methods) the area beneath andin the area of the inboard aileron hinge bracket on the aileron spar for cracks in accordance with the INSTRUCTIONS section of Piper service bulletin (SB) No. 967, dated January 24, 1994, or Piper SB No. 974, dated October 19, 1994, whichever service bulletin applies to the particular model and serial number.

(1) If cracks are found on the aileron spar:

(i) Prior to further flight, inspect the corresponding aileron rib at the inboard aileron hinge bracket location;

(ii) Prior to further flight, replace any cracked spar assembly and any cracked aileron rib in accordance with the applicable Maintenance Manual;

(iii) Prior to further flight, replace the inboard aileron hinge brackets with an inboard aileron hinge bracket of improved design, part number (P/N) 74461-02 (left) and P/N 74461-03 (right), in accordance with the INSTRUCTIONS section of Piper SB No. 967, dated January 24, 1994, or Piper SB No. 974, dated October 19, 1994, as applicable.

(2) If nocracks are found, prior to further flight, replace the inboard aileron hinge brackets with a part of improved design P/N 74461-02 (left) and P/N 74461-03 (right), in accordance with the INSTRUCTIONS section of Piper SB No. 967, dated January 24, 1994, or Piper SB No. 974, dated October 19, 1994, as applicable.

(b) If the inboard aileron hinge brackets, P/N 74461-02 (left) or P/N 74461-03 (right) have been ordered from the manufacturer but are not available, prior to further flight, and thereafter at intervals not to exceed 100 hours TIS, dye penetrant inspect beneath and in the vicinity of the inboard aileron hinge bracket for cracks in accordance with the INSTRUCTIONS section of Piper SB No. 967, dated January 24, 1994, or Piper SB No. 974, dated October 19, 1994, as applicable.

(c) If any one of the following occurs, prior to further flight, terminate the above repetitive inspections, replace any cracked aileron rib and any cracked spar assembly (if applicable), and replace the inboard aileron hinge bracket as specified in paragraph (a)(1)(iii) of this AD:

(1) Parts become available;

(2) An inboard aileron bracket hinge, aileron spar or aileron rib is found cracked; or

(3) 1,000 hours TIS are accumulated after the initial inspection required by this AD.

(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, FAA, Atlanta Aircraft Certification Office, Campus Building, 1701 Columbia Avenue, suite 2- 160, College Park, Georgia 30337-2748. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager,Atlanta Aircraft Certification Office.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta Aircraft Certification Office.

(f) The inspections and replacements required by this AD shall be done in accordance with Piper Service Bulletin No. 967, dated January 24, 1994, or Piper Service Bulletin No. 974, dated October 19, 1994. 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., Attn: Customer Service, 2926 Piper Dr., Vero Beach, Florida, 32960. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief 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.

(g) This amendment becomes effective on December10, 1996.

Events Leading to This Action
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to Piper PA31, PA31P, PA31T, and PA42 series airplanes was published in the Federal Register on March 27, 1996 (61 FR 13468). The action proposed to require:

- inspecting the aileron spar beneath and in the area of the inboard aileron hinge bracket for cracks;

- if cracks are found in the area of the aileron spar, inspecting the aileron rib for cracks, and replacing the cracked spar assembly and any cracked rib;

- replacing the inboard aileron hinge brackets with part number (P/N) 74461-02 (left) and P/N 74461-03 (right).

Related Service Information
Accomplishment of the proposed action would be in accordance with Piper Service Bulletin (SB) No. 967, dated January 24, 1994 or Piper SB No. 974, dated October 19, 1994.

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

The first commenter recommends that the AD state specifically that prior compliance with the applicable service bulletin (SB) be considered compliance with the requirements of the AD. The commenter has complied with Piper SB 974 and adds that paragraph (a) should only be required on aircraft that have not installed the redesigned aileron hinge brackets. The commenter continues to state that paragraph (a) as presently worded may be interpreted to require inspection of the aileron spar on all affected aircraft regardless of the part number (P/N) of the inboard hinge installed on the aircraft.

The FAA concurs that additional clarification is justified. The inspection of the aileron spar is intended to be required for aircraft that have not previously installed P/N 74461-02 (left) and P/N 74461-03 (right) inboard hinges. The "Applicability" section in the AD will be changed tostate, "The following airplane models and serial numbers that are not equipped with part number (P/N) 74461-02 (left) and P/N 74461-03 (right) inboard aileron hinge brackets, certificated in any category."

The second commenter recommends that the AD be applicable to aircraft with greater than 3,000 hours time-in-service (TIS). This commenter operates Piper airplane Models PA-31-350, a PA-31, and a PA-31P with 11,000, 8,600 and 2,000 hours TIS respectively, and states that based on their fleet experience, cracking is most likely to appear at or after 3,000 hours TIS and recommends the 3,000 hour TIS as the threshold for this AD.
The FAA concurs and points out that the proposed action already proposes what the commenter is recommending. The compliance time as proposed specifies compliance "upon the accumulation of 3,000 hours TIS, or within the next 100 hours TIS, whichever occurs later."

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 and the clarification of the "Applicability" section. 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.

Cost Impact
The FAA estimates that 2,501 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 7 workhours per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. Parts cost $300 per airplane. Based on these figures, the total cost impact for the initial inspection and the modification required by this AD on U.S. operators is estimated to be $1,800,720 or $720 per airplane. This figure does not include the amount for repetitive inspections and is based on the assumption that all of the owners/operators of the affected airplanes have not inspected for cracks, repaired cracks, or incorporated the modification of this AD. The FAA has no way of determining the number of repetitive inspections each owner/operator will incur before the modification is accomplished.

Piper has informed the FAA that parts have been distributed to equip approximately 1,250 airplanes. Assuming that these distributed parts are incorporated on the affected airplanes, the cost of the AD would be reduced by $900,000 from $1,800,720 to $900,720.

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 USC 106(g), 40113, 44701.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: