AD 68-17-03R1

We are adopting a new airworthiness directive (AD) to revise AD 68-17-03, which applies to all Pilatus Aircraft Ltd. (Pilatus) PC-6 series airplanes. AD 68-17-03 requires you to repetitively inspect the rudder end rib for cracks and replace the rudder end rib with a modified rudder end rib when you find cracks. Installing the modified rudder end rib terminates the repetitive inspection requirements of AD 68-17-03. Under a licensing agreement with Pilatus, Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation) produced Model PC-6 series airplanes (manufacturer serial numbers 2001 through 2092) in the United States. AD 68-17-03 was intended to apply to all affected serial numbers of Model PC-6 series airplanes listed on Type Certificate Data Sheet (TCDS) No. 7A15, including the Fairchild-produced airplanes. Consequently, this AD clarifies that all models of the PC-6 airplane on TCDS No. 7A15 (including those models produced under the licensing agreement by Fairchild Republic Company) are included in the applicability. We are issuing this AD to detect and correct cracks in the rudder end rib, which could result in failure of the rudder end rib. This failure could result in loss of rudder control.

Final rule.

68-17-03R1 Pilatus Aircraft LTD.: Amendment 39-14656; Docket No. FAA-2006-24094; Directorate Identifier 2006-CE-20-AD.

Effective Date

(a) This AD becomes effective on August 3, 2006.

Affected ADs

(b) This AD revises AD 68-17-03, Amendment 39-634.

Applicability

(c) This AD affects the following airplane models, all manufacturer serial numbers (MSN), that are certificated in any category:

Note: MSNs 2001 through 2092 were manufactured by Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, and Fairchild-Hiller Corporation) in the United States under a licensing agreement and are covered by Type Certificate Data Sheet No. 7A15.

(1) PC-6
(2) PC-6-H1
(3) PC-6-H2
(4) PC-6/350
(5) PC-6/350-H1
(6) PC-6/350-H2
(7) PC-6/A
(8) PC-6/A-H1
(9) PC-6/A-H2
(10) PC-6/B-H2
(11) PC-6/B1-H2
(12) PC-6/B2-H2
(13) PC-6/B2-H4
(14) PC-6/C-H2
(15) PC-6/C1-H2

Unsafe Condition

(d) ThisAD results from fatigue cracks found in the bottom nose rib on the rudders of certain PC-6 airplanes. We are issuing this AD to detect and correct cracks in the rudder end rib, which could result in failure of the rudder. This failure could lead to loss of rudder control.

Compliance

(e) To address this problem, you must do the following:

Actions
Compliance
Procedures

(1) With the aid of a mirror, inspect the rudder end rib, part number (P/N) 6302.27 (or FAA-approved equivalent P/N) for crack(s).
Within the next 50 hours time-in-service after August 19, 1968 (the effective date of AD 68 17 03). Repetitively inspect thereafter at intervals not to exceed 50 hours TIS.
Follow Pilatus Service Bulletin
No. 80, dated April 1968.

(2) If you detect a crack or cracks during any inspection required in
paragraph (e)(1) of this AD, replace the rudder end rib with a modified rudder end rib assembly, P/N 6302.26 Pos. 2, channelreinforcement, P/N 113.40.06.002, and torque tube, P/N
113.40.06.003 (or FAA-approved equivalent P/Ns).
Before further flight after any inspection required in paragraph (e)(1) of this AD in which you find cracks. Installing the modified rudder end rib terminates the repetitive inspection requirement in
paragraph (e)(1) of this AD.
Follow Pilatus Service Bulletin No. 80, dated April 1968.

(3) 14 CFR 21.303 allows for replacement parts through parts manu-
facturer approval (PMA). The phrase or FAA-approved equivalent
P/N in this AD is intended to signify those parts that are PMA parts approved through identicality to the design of the part under the type certificate and replacement parts to correct the unsafe condition under PMA (other than identicality). If parts are installed that are identical to the unsafe parts, then the corrective actions of the AD affect these parts also. In addition, equivalent replacement parts to correct the unsafe condition under PMA (other than identicality) may also be installed provided they meet current airworthiness standards, which include those actions cited in this AD.
Not applicable
Not applicable.

(4) Installing the modified rudder end rib assembly, P/N 6302.26 Pos.
2, channel reinforcement, P/N 113.40.06.002, and torque tube, P/N
113.40.06.003 (or FAA-approved equivalent P/Ns), terminates the
repetitive inspection requirement in paragraph (e)(1) of this AD.
Not applicable
Not applicable.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Standards Office, ATTN: Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; facsimile: (816) 329-4090, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(g) AMOCs approved for AD 68-17-03 are approved for this AD.Related Information

(h) Swiss AD Number HB 2005-289, effective date August 23, 2005, also addresses the subject of this AD.

Material Incorporated by Reference

(i) You must do the actions required by this AD following Pilatus Service Bulletin No. 80, dated April 1968. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get a copy of this service information, contact Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224. To review copies of this service information, go to the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html or call (202) 741-6030. To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001 or on the Internet at http://dms.dot.gov. The docket number is FAA-2006-24094; Directorate Identifier 2006-CE-20-AD.

Discussion

On April 17, 2006, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Pilatus PC-6 series airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on April 24, 2006 (71 FR 20919). The NPRM proposed to revise AD 68-17-03 with a new AD that would retain all actions currently required by AD 68-17-03 and would clarify the applicability of the affected airplanes by:

Identifying those airplanes produced in the United States through a licensing agreement with the Fairchild Republic Company; and

Listing all Pilatus Model PC-6 series airplanes on Type Certificate Data Sheet No. 7A15 in the applicability section.

Comments

We provided the public the opportunity to participate in developing this AD. We received one comment in favor of the proposed AD.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.

Costs of Compliance

We estimate that this AD affects 49 airplanes in the U.S. registry.

We estimate the following costs to do the inspection:

Labor cost
Parts cost
Total cost for each airplane
Total cost on U.S. operators
1 work-hour $80 an hour = 80.
Not applicable
$80
$80 49 = $3,920.

We estimate the following costs to do any necessary replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need this replacement:

Labor cost
Parts cost
Total cost for each airplane
9 work-hours $80 an hour = $720
$821
$1,541

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106 describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this AD.

Regulatory Findings

We have determined that this AD will not have federalism implications underExecutive Order 13132. This AD will not have a substantial direct effect 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.

For the reasons discussed above, I certify that this AD:

1. Is not a "significant regulatory action'' under Executive Order 12866;

2. Is not a "significant rule'' under the 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.

We prepared a summary of the costs to comply with this AD (and other information as included in the Regulatory Evaluation) and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "Docket No. FAA-2006-24094; Directorate Identifier 2006-CE-20-AD'' in your request.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under 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.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD) 68-17-03, Amendment 39-634, and adding the following new AD: