AD 97-15-14

This amendment adopts a new airworthiness directive (AD) that applies to Industrie Aeronautiche e Meccaniche Rinaldo Piaggio S.p.A. (Piaggio) Model P-180 airplanes. This action requires inspecting for cracks around the vertical pin and the torque tube bottom flange of the rudder, and the fasteners that connect the torque tube to the bottom flange (torque tube bottom flange assembly). If cracks are not found, repetitively inspect until cracks are visible. If cracks are evident, this action requires modifying the rudder torque tube bottom flange assembly by replacing the cracked part with a part of improved design, which terminates the repetitive inspection. This AD is the result of several reports of fatigue cracks around the pin that vertically supports the rudder axle. The actions specified by this AD are intended to prevent fatigue cracks in the rudder torque tube bottom flange, which could result in loss of rudder control and possible loss of the airplane.

Final rule.

97-15-14 INDUSTRIE AERONAUTICHE E MECCANICHE RINALDO PIAGGIO S.P.A (PIAGGIO): Amendment No. 39-10088; Docket No. 96-CE-56-AD.

Applicability: Model P-180 airplanes (all serial numbers), certificated in any category.

NOTE 1: This AD applies to the 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 the airplane that has been modified, altered, or repaired so that the performance of the requirements of this AD are 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: Required within the next 100 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished, and thereafter as indicated in the body of this AD.

To prevent fatigue cracks in the rudder torque tube bottom flange assembly, which could result in loss of rudder control and possible loss of the airplane, accomplish the following:

(a) Inspect the torque tube bottom flange assembly of the rudder for cracks (using a dye penetrant method) and visually inspect for cracks in the fasteners that connect the torque tube to the bottom flange.

NOTE 2: The inspection in Part A of the Compliance section of Piaggio Service Bulletin (SB) 80-0076, ORIGINAL ISSUE: May 30, 1995, uses different criteria than the inspection required in paragraph (a) of this AD. This AD takes precedence over Piaggio SB 80-0076.

(b) If cracks are found, prior to further flight, modify the rudder torque tube bottom flange assembly by replacing the cracked part with a part of improved design inaccordance with Part B and Attachment #1 of the ACCOMPLISHMENT INSTRUCTIONS of Piaggio SB 80-0076, ORIGINAL ISSUE: May 30, 1995.

(c) If no cracks are found, continue to inspect at intervals not to exceed 100 hours TIS thereafter, until cracks appear. If cracks appear during any inspection required by this AD, prior to further flight, modify the rudder torque tube bottom flange assembly by replacing the cracked part with a part of improved design in accordance with Part B and Attachment #1 of the ACCOMPLISHMENT INSTRUCTIONS of Piaggio SB 80-0076, ORIGINAL ISSUE: May 30, 1995.

(d) Modifying the rudder torque tube bottom flange assembly by replacing torque tube bottom flange assembly with an improved torque tube bottom flange assembly as specified in paragraphs (b) and (c) of this AD is considered a terminating action for the repetitive inspections required in paragraph (c) of this AD.

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199of 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, Small Airplane Directorate, Aircraft Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(g) The inspections, modification, and replacement required by this AD shall be done in accordance with Piaggio Service Bulletin 80-0076, ORIGINAL ISSUE: May 30, 1995. 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 of this service bulletin may be obtained from Industrie Aeronautiche e Meccaniche Rinaldo Piaggio S.p.A., Via Ciobrario, 4 16154 Genoa, Italy. Copies of this document 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.

(h) This amendment becomes effective on September 19, 1997.

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 Piaggio Model P-180 airplanes was published in the Federal Register on February 24, 1997 (62 FR 8196). The action proposed to require inspecting for cracks in the torque tube bottom flange, the fasteners, and vertical support pin of the rudder; and, if cracks are found, modifying the rudder torque tube bottom flange assembly by replacing the cracked part with a part of improved design. If no cracks are found, the proposed action would require repetitively inspecting the area until cracks appear and then modifying the rudder torque tube bottom flange assembly (part number (P/N) 80-373108-103 or an FAA approved equivalent) by replacing the cracked part with a part of improved design (P/N 80-373201-001 or an FAA approved equivalent). Accomplishment of the proposed modification would be in accordance with Piaggio Service Bulletin (SB) 80-0076, Original Issue: May 30, 1995.

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, including the service 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 AD, Service Bulletin, and RAI AD
I.A.M. Rinaldo Piaggio SB 80-0076, Original Issue May 30, 1995, and the RAI AD No. 95-183, dated July 3, 1995, specify repetitively inspecting every 500 hours time-in-service (TIS) using a dye penetrant method, and if the crack lengths are greater than 6 mm, the part must be replaced prior to further flight. If the crack lengths are greater than 3 mm, but less than 6 mm, the part must be replaced within the next 50 hours TIS; and, if the cracks are less than 3 mm, then the parts must be replaced within the next 100 hours TIS.

The FAA has established a policy to disallow airplane operation when known cracks exist in primary structure, unless the ability to sustain ultimate load with these cracks is proven. The torque tube bottom flange, the fasteners, and the vertical support pin in the rudder (torque tube bottom flange assembly) are considered primary structure, and the FAA has not received any analysis to prove that ultimate load can be sustained with cracks in this area. For this reason, the FAA has determined that AD action should be taken to require replacement of any cracked torque tube bottom flange assembly in the rudder.

Cost Impact
The FAAestimates that 4 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 6 workhours per airplane to accomplish the initial inspection and that the average labor rate is approximately $60 an hour. Parts are not accounted for in this cost analysis because, on some airplanes, cracks may never be discovered during one of these inspections. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,440 ($360 per airplane). The FAA is not taking into account the cost for the repetitive inspections because there is no way to determine the number of repetitive inspections that will be incurred over the life of the airplane.

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.

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