Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 Airplanes, 35502-35505 [06-5532]

Download as PDF 35502 Federal Register / Vol. 71, No. 119 / Wednesday, June 21, 2006 / Rules and Regulations believed to represent the worst case to which an airplane would be exposed in the operating environment. These special conditions require qualification of systems that perform critical functions, as installed in aircraft, to the defined HIRF environment in paragraph 1 or, as an option to a fixed value using laboratory tests, in paragraph 2, as follows: (1) The applicant may demonstrate that the operation and operational capability of the installed electrical and electronic systems that perform critical functions are not adversely affected when the aircraft is exposed to the HIRF environment defined below: Field strength (volts per meter) Frequency Peak 10 kHz–100 kHz 100 kHz–500 kHz ................ 500 kHz–2 MHz 2 MHz–30 MHz 30 MHz–70 MHz 70 MHz–100 MHz ............... 100 MHz–200 MHz ............... 200 MHz–400 MHz ............... 400 MHz–700 MHz ............... 700 MHz–1 GHz 1 GHz–2 GHz ... 2 GHz–4 GHz ... 4 GHz–6 GHz ... 6 GHz–8 GHz ... 8 GHz–12 GHz 12 GHz–18 GHz 18 GHz–40 GHz Average 50 50 50 50 100 50 0 50 100 50 50 50 100 100 100 100 700 700 2000 3000 3000 1000 3000 2000 600 50 100 200 200 200 200 300 200 200 sroberts on PROD1PC70 with RULES The field strengths are expressed in terms of peak root-mean-square (rms) values. Or, (2) The applicant may demonstrate by a system test and analysis that the electrical and electronic systems that perform critical functions can withstand a minimum threat of 100 volts per meter, electrical field strength, from 10 kHz to 18 GHz. When using this test to show compliance with the HIRF requirements, no credit is given for signal attenuation due to installation. A preliminary hazard analysis must be performed by the applicant, for approval by the FAA, to identify either electrical or electronic systems that perform critical functions. The term ‘‘critical’’ refers to functions, whose failure would contribute to, or cause, a failure condition that would prevent the continued safe flight and landing of the airplane. The systems identified by the hazard analysis that perform critical functions are candidates for the application of HIRF requirements. A VerDate Aug<31>2005 16:35 Jun 20, 2006 Jkt 208001 system may perform both critical and non-critical functions. Primary electronic flight display systems, and their associated components, perform critical functions such as attitude, altitude, and airspeed indication. The HIRF requirements apply only to critical functions. Compliance with HIRF requirements may be demonstrated by tests, analysis, models, similarity with existing systems, or any combination of these. Service experience alone is not acceptable since normal flight operations may not include an exposure to the HIRF environment. Reliance on a system with similar design features for redundancy as a means of protection against the effects of external HIRF is generally insufficient since all elements of a redundant system are likely to be exposed to the fields concurrently. Applicability As discussed above, these special conditions are applicable to the Rockwell Twin Commander Model 690B airplanes. Should Rickenbacker Avionics apply at a later date for a supplemental type certificate to modify any other model on the same type certificate, Type Certificate No. 2A4, to incorporate the same novel or unusual design feature, the special conditions would apply to that model as well under the provisions of § 21.101. Conclusion This action affects only certain novel or unusual design features on one model of airplane. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the airplane. The substance of these special conditions has been subjected to the notice and comment period in several prior instances and has been derived without substantive change from those previously issued. It is unlikely that prior public comment would result in a significant change from the substance contained herein. For this reason, and because a delay would significantly affect the certification of the airplane, which is imminent, the FAA has determined that prior public notice and comment are unnecessary and impracticable, and good cause exists for adopting these special conditions upon issuance. The FAA is requesting comments to allow interested persons to submit views that may not have been submitted in response to the prior opportunities for comment described above. PO 00000 Frm 00012 Fmt 4700 Sfmt 4700 List of Subjects in 14 CFR Part 23 Aircraft, Aviation safety, Signs and symbols. Citation The authority citation for these special conditions is as follows: I Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and 21.101; and 14 CFR 11.38 and 11.19. The Special Conditions I Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for the Rockwell Twin Commander Model 690B airplanes modified by Rickenbacker Avionics to add EFS–50 EFIS installation. 1. Protection of electrical and electronic systems from High Intensity Radiated Fields (HIRF). Each system that performs critical functions must be designed and installed to ensure that the operations, and operational capabilities of these systems to perform critical functions, are not adversely affected when the airplane is exposed to high intensity radiated electromagnetic fields external to the airplane. 2. For the purpose of these special conditions, the following definition applies: Critical Functions: Functions whose failure would contribute to, or cause, a failure condition that would prevent the continued safe flight and landing of the airplane. Issued in Kansas City, Missouri, on June 12, 2006. James E. Jackson, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E6–9818 Filed 6–20–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–24094; Directorate Identifier 2006–CE–20–AD; Amendment 39– 14656; AD 68–17–03R1] RIN 2120–AA64 Airworthiness Directives; Pilatus Aircraft Ltd. Models PC–6, PC–6–H1, PC–6–H2, PC–6/350, PC–6/350–H1, PC– 6/350–H2, PC–6/A, PC–6/A–H1, PC–6/ A–H2, PC–6/B–H2, PC–6/B1–H2, PC–6/ B2–H2, PC–6/B2–H4, PC–6/C–H2, and PC–6/C1–H2 Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). AGENCY: E:\FR\FM\21JNR1.SGM 21JNR1 Federal Register / Vol. 71, No. 119 / Wednesday, June 21, 2006 / Rules and Regulations ACTION: Final rule. SUMMARY: 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. DATES: This AD becomes effective on August 3, 2006. As of August 3, 2006, the Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulation. ADDRESSES: For service information identified in this AD, contact Pilatus Aircraft Ltd., Customer Liaison Manager, CH–6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224. 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. FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329– 4059; facsimile: (816) 329–4090. SUPPLEMENTARY INFORMATION: 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 1 work-hour × $80 an hour = 80. .................................................... Not applicable ............................ $80 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 35503 Total cost on U.S. operators $80 × 49 = $3,920. 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 sroberts on PROD1PC70 with RULES 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 VerDate Aug<31>2005 16:35 Jun 20, 2006 Jkt 208001 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 under PO 00000 Frm 00013 Fmt 4700 Sfmt 4700 Executive 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 E:\FR\FM\21JNR1.SGM 21JNR1 35504 Federal Register / Vol. 71, No. 119 / Wednesday, June 21, 2006 / Rules and Regulations 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: I 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. PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: I Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 68–17–03, Amendment 39–634, and adding the following new AD: I 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 (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) This AD 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 (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. 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. Not applicable .......................................................... Follow Pilatus Service Bulletin No. 80, dated April 1968. Follow Pilatus Service Bulletin No. 80, dated April 1968. Not applicable .......................................................... Not applicable. (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, channel reinforcement, P/N 113.40.06.002, and torque tube, P/N 113.40.06.003 (or FAA-approved equivalent P/Ns). (3) 14 CFR 21.303 allows for replacement parts through parts manufacturer 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. (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. sroberts on PROD1PC70 with RULES Alternative Methods of Compliance (AMOCs) Related Information (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. VerDate Aug<31>2005 16:35 Jun 20, 2006 Jkt 208001 (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 PO 00000 Frm 00014 Fmt 4700 Sfmt 4700 Procedures Not applicable. 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 E:\FR\FM\21JNR1.SGM 21JNR1 Federal Register / Vol. 71, No. 119 / Wednesday, June 21, 2006 / Rules and Regulations 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. Issued in Kansas City, Missouri, on June 12, 2006. James E. Jackson, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 06–5532 Filed 6–20–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2005–22594; Directorate Identifier 2005–NE–28–AD; Amendment 39– 14659; AD 2006–13–06] RIN 2120–AA64 Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) 250–B and 250–C Series Turboprop and Turboshaft Engines Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. sroberts on PROD1PC70 with RULES AGENCY: SUMMARY: The FAA is adopting a new airworthiness directive (AD) for RollsRoyce Corporation 250–B and 250–C series turboprop and turboshaft engines with certain part numbers (P/Ns) of gas producer rotor assembly tie bolts manufactured by EXTEX Ltd., Pacific Sky Supply Inc., Rolls-Royce Corporation (RRC), and Superior Air Parts Inc. This AD requires operators to remove from service affected gas producer rotor assembly tie bolts, and install serviceable tie bolts. This AD results from eleven reports of RRC tie bolt failure due to high cycle fatigue. We are issuing this AD to prevent tie bolt failure that could cause loss of engine power, resulting in a first stage turbine wheel overspeed and an uncontained engine failure. DATES: This AD becomes effective July 26, 2006. ADDRESSES: You may examine the AD docket on the Internet at http:// dms.dot.gov or in Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC. FOR FURTHER INFORMATION CONTACT: • Robert Baitoo, Aerospace Engineer, Los Angeles Aircraft Certification VerDate Aug<31>2005 16:35 Jun 20, 2006 Jkt 208001 Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712–4137; telephone: (562) 627–5245, fax: (562) 627–5210, for questions about, EXTEX Ltd., or Pacific Sky Supply Inc. gas producer rotor assembly tie bolts. • John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018–4696; telephone (847) 294–8180; fax (847) 294–7834, for questions about RRC gas producer rotor assembly tie bolts. • Jurgen Priester, Aerospace Engineer, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 76137–4298, telephone (817) 222–5159, fax (817) 222–5785, for questions about Superior Air Parts Inc. gas producer rotor assembly tie bolts. SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to Rolls-Royce Corporation 250–B and 250–C series turboprop and turboshaft engines with certain P/Ns of gas producer rotor assembly tie bolts manufactured by EXTEX Ltd., Pacific Sky Supply Inc., RRC, and Superior Air Parts Inc. We published the proposed AD in the Federal Register on November 10, 2005 (70 FR 68381). That action proposed to require operators to remove from service affected gas producer rotor assembly tie bolts. Examining the AD Docket You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647–5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them. Comments We provided the public the opportunity to participate in the development of this AD. We have considered the comments received. Request To Exclude Parts Manufacturer Approval (PMA) Tie Bolts One commenter requests that the PMA tie bolts be excluded from the AD action, because there are no reported failures of the PMA tie bolts. Also, the commenter states that there are numerous opportunities for significant design differences between PMA tie bolts approved under Test and PO 00000 Frm 00015 Fmt 4700 Sfmt 4700 35505 Computation, and the original equipment manufacturer (OEM) tie bolts. We do not agree. Although there are no reported failures of PMA parts, the tie bolts from all four manufacturers are essentially the same and share many common features. The fact that there are no reported failures of PMA parts is statistically insignificant since the PMA parts only account for several hundred of the approximately 5,000 tie bolts in service, and there have been only 11 failures. Additionally, failures of a specific part number are not a prerequisite for declaring an unsafe condition. A failure mode’s net result on the product (in this case loss of engine power, first stage turbine wheel overspeed, and an uncontained engine failure); the assumed or predicted rate of occurrence, and other factors linking affected or suspect parts to failed parts, help make that decision. While minor differences may exist between the OEM tie bolts and the PMA tie bolts, the commenter gave no justification as to how those unnamed differences should exempt the PMA parts from this AD action. Finally, we did compare design data as part of the decision making process. Request To Withdraw the Proposed AD The same commenter requests that we withdraw the proposed AD and not reissue it until we are prepared to fully disclose what design features caused the tie bolt failures. The commenter further states that since the tie bolt requires a sustained preload for safe operation, one would expect that maintenance or assembly practices are more likely contributors, as the likelihood of highcycle-fatigue failures increases if the preload is not established or maintained correctly. We do not agree. While they may have minor differences between them, the tie bolts from all four manufacturers are essentially the same and share many common features. The commenter provides no data to support the assertion that maintenance or assembly practices are more likely contributors to the high-cycle-fatigue failures. Analysis of the failures did not find any assembly problems. We did not change the AD. Request To Provide Instructions on How to Make the Engine Airworthy The same commenter requests that we provide instructions on how to make the engine airworthy. The commenter states that the AD action essentially specifies an action of ‘‘remove, and do not reinstall, tie bolt part numbers listed in Table 1.’’ The commenter assumes there E:\FR\FM\21JNR1.SGM 21JNR1

Agencies

[Federal Register Volume 71, Number 119 (Wednesday, June 21, 2006)]
[Rules and Regulations]
[Pages 35502-35505]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-5532]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24094; Directorate Identifier 2006-CE-20-AD; 
Amendment 39-14656; AD 68-17-03R1]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-
6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, 
PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, 
and PC-6/C1-H2 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

[[Page 35503]]


ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: 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.

DATES: This AD becomes effective on August 3, 2006.
    As of August 3, 2006, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in the 
regulation.

ADDRESSES: For service information identified in this AD, contact 
Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224.
    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.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, FAA, 
Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: (816) 329-4059; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

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:

----------------------------------------------------------------------------------------------------------------
                                                                          Total cost for     Total cost on U.S.
                Labor cost                          Parts cost            each airplane          operators
----------------------------------------------------------------------------------------------------------------
1 work-hour x $80 an hour = 80...........  Not applicable.............               $80      $80 x 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:

------------------------------------------------------------------------
                                                        Total cost for
             Labor cost                 Parts cost       each airplane
------------------------------------------------------------------------
9 work-hours x $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 under Executive 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

[[Page 35504]]

    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

0
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

0
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]

0
2. The FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 
68-17-03, Amendment 39-634, and adding the following new AD:

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) This AD 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,  Within the next   Follow Pilatus Service
 inspect the rudder end rib,    50 hours time-    Bulletin No. 80, dated
 part number (P/N) 6302.27      in-service        April 1968.
 (or FAA-approved equivalent    after August
 P/N) for crack(s).             19, 1968 (the
                                effective date
                                of AD 68-17-
                                03).
                                Repetitively
                                inspect
                                thereafter at
                                intervals not
                                to exceed 50
                                hours TIS.
(2) If you detect a crack or   Before further    Follow Pilatus Service
 cracks during any inspection   flight after      Bulletin No. 80, dated
 required in paragraph (e)(1)   any inspection    April 1968.
 of this AD, replace the        required in
 rudder end rib with a          paragraph
 modified rudder end rib        (e)(1) of this
 assembly, P/N 6302.26 Pos.     AD in which you
 2, channel reinforcement, P/   find cracks.
 N 113.40.06.002, and torque    Installing the
 tube, P/N 113.40.06.003 (or    modified rudder
 FAA-approved equivalent P/     end rib
 Ns).                           terminates the
                                repetitive
                                inspection
                                requirement in
                                paragraph
                                (e)(1) of this
                                AD.
(3) 14 CFR 21.303 allows for   Not applicable..  Not applicable.
 replacement parts through
 parts manufacturer 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.
(4) Installing the modified    Not applicable..  Not applicable.
 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.
------------------------------------------------------------------------

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

[[Page 35505]]

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.


    Issued in Kansas City, Missouri, on June 12, 2006.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-5532 Filed 6-20-06; 8:45 am]
BILLING CODE 4910-13-P