Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes, 19998-20001 [06-3725]

Download as PDF 19998 Federal Register / Vol. 71, No. 75 / Wednesday, April 19, 2006 / Rules and Regulations TABLE 3.—NEW SAFE LIFE FOR WING SPAR LOWER CAPS Wing spar lower cap safe-life Serial No. All beginning with AT–802–0001 ................................................................................................................................... All beginning with AT–802A–0001 ................................................................................................................................ (k) Report any cracks you find within 10 days after the cracks are found or within 10 days after April 21, 2006 (the effective date of this AD), whichever occurs later. (1) Include in your report the aircraft serial number, aircraft TIS, wing spar cap TIS, crack location and size, corrective action taken, and a point of contact name and phone number. Send your report to Andrew McAnaul, Aerospace Engineer, ASW–150 (c/o MIDO–43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 308–3365; fascimile: (210) 308–3370. (2) The Office of Management and Budget (OMB) approved the information collection requirements contained in ths regulation under the provisions of the Paperwork Reduction Act and assigned OMB Control Number 2120–0056. May I Request an Alternative Method of Compliance? (l) The Manager, Fort Worth Airplane Certification Office, FAA, has the authority to aprove alternative methods of compliance for this AD, if requested using the procedures found in 14 CFR 39.19. For information on any already approved alternative methods of compliance or for information pertaining to this AD, contact Andrew McAnual, Aerospace Engineer, ASW–150 (c/o MIDO– 43), 10100 Reunion Place, suite 650, San Antonio, Texas 78216; telephone: (210) 308– 3365; facsimile: (210) 308–3370. (m) AMOCs approved for AD 2001–10–04, AD 2001–10–04 R1, or AD 2002–11–05 for the Models AT–802 and AT–802A airplanes are not considered approved for this AD. rmajette on PROD1PC67 with RULES1 Special Flight Permit (n) Under 14 CFR part 39.23, we are allowing special flight permits for the purpose of compliance with this AD under the following conditions: (1) Only operate in day visual flight rules (VFR). (2) Ensure that the hopper is empty. (3) Limit airspeed to 135 miles per hour (mph) indicated airspeed (IAS). (4) Avoid any unnecessary g-forces. (5) Avoid areas of turbulence. (6) Plan the flight to follow the most direct route. Does This AD Incorporate Any Material by References? (o) You must do the actions required by this AD following the instructions in Snow Engineering Co. Process Specification #197, page 1, revised June 4, 2002; pages 2 through 4, dated February 23, 2001; and page 5, dated May 3, 2002; Snow Engineering Co. Process Specification #204, Rev. C, dated November 16, 2004; Snow Engineering Co. Service Letter #215, page 5, titled ‘‘802 Spar Inspection Holes and Vent Tube Mod,’’ dated November 19, 2003; Snow Engineering Co. VerDate Aug<31>2005 16:42 Apr 18, 2006 Jkt 205001 Service #240, dated September 30, 2004; Snow Engineering Co. Service Letter #244, dated April 25, 2005; Snow Engineering Co. Drawing Number 20975, Sheet 2, Rev. A, dated September 1, 2004; Snow Engineering Co. Drawing Number 20975, Sheet 3, dated January 6, 2005; and Snow Engineering Co. Drawing Number 20995, Sheet 2, Rev. C., dated September 28, 2004. The Director of the Federal Register approved the incorporation by reference of this service information in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get a copy of this service information, contact Air Tractor, Incorporated, P.O. Box 485, Olney, Texas 76374. 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: https://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; US Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL–401, Washington, DC 20590–0001 or on the Internet at https://dms.dot.gov. The docket number FAA–2005–20591; Directorate Identifier 2005–20591; Directorate Identifier 2005–CE– 14–AD. Issued in Kansas City, Missouri, on April 10, 2006. David R. Showers, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 06–3613 Filed 4–18–06; 8:45am] BILLING CODE 4910–13–M DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2004–19220; Directorate Identifier 2004–CE–27–AD; Amendment 39– 14568; AD 2006–08–11] RIN 2120–AA64 Airworthiness Directives; Pilatus Aircraft Ltd. Models PC–12 and PC–12/ 45 Airplanes Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. AGENCY: SUMMARY: We are adopting a new airworthiness directive (AD) for all Pilatus Aircraft Ltd. Models PC–12 and PO 00000 Frm 00014 Fmt 4700 Sfmt 4700 8,163 hours TIS. 8,648 hours TIS. PC–12/45 airplanes equipped with certain crew seat bucket assemblies with and without a backrest recline system. This AD requires you to replace the backrest tubes on these crew seat bucket assemblies at a specified time and adds a life limit for these backrest tubes. This AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. We are issuing this AD to prevent cracks in the backrest tubes of certain crew seat bucket assemblies, which could result in failure of the seat system. This failure could lead to the pilot and co-pilot’s reduced ability to control the airplane. This failure could also affect the proper function of the seat restrain system in the case of an emergency landing. DATES: This AD becomes effective on June 2, 2006. ADDRESSES: For information identified in this AD, contact Pilatus Aircraft Ltd., Customer Support Manager, CH–6371 Stans, Switzerland; telephone: +41 41 619 6208; fax: +41 41 619 7311; or Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: (303) 465–9099; fax: (303) 465–6040. 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– 0001 or on the Internet at https:// dms.dot.gov. The docket number is FAA–2004–19220; Directorate Identifier 2004–CE–27–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; fax: (816) 329–4090. SUPPLEMENTARY INFORMATION: Discussion On February 7, 2006, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that would apply to all Pilatus Aircraft Ltd. (Pilatus) Models PC–12 and PC–12/ 45 airplanes equipped with certain crew seat bucket assemblies with and without a backrest recline system. This proposal E:\FR\FM\19APR1.SGM 19APR1 Federal Register / Vol. 71, No. 75 / Wednesday, April 19, 2006 / Rules and Regulations was published in the Federal Register as a notice of proposed rulemaking (NPRM) on February 14, 2006 (71 FR 7698). The NPRM proposed to require you to replace the backrest tubes on certain crew seat bucket assemblies at a specified time and add a life limit for the backrest tubes. Comments We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA’s response to each comment: Comment Issue No. 1: Remove Reference to PC12 Maintenance Manual Temporary Revision No. 04–13, Dated June 15, 2005 The manufacturer states that PC–12 Interactive Electronic Technical Publication (IETP) Revision 9 (which will include Aircraft Maintenance Manual (AMM) Revision 17) will supersede PC12 Maintenance Manual Temporary Revision No. 04–13, dated June 15, 2005, by March 31, 2006, by incorporating the information into the IETP. The commenter requests to remove the reference to PC12 Maintenance Manual Temporary Revision No. 04–13, dated June 15, 2005, from the final rule AD action. We agree with the commenter and will change the final rule AD action. Comment Issue No. 2: Change the Compliance Time for Replacing Certain Crew Seat Bucket Assemblies The manufacturer states the life limit and the compliance time for replacing crew seat bucket assemblies without a recline system, part numbers (P/Ns) 959.30.01.131, 959.30.01.132, 959.30.01.133, and 959.30.01.134 (or FAA-approved equivalent P/Ns), is too conservative. The manufacturer states there have not been any of these seats found with cracks and they have confidence the life limit could be increased from 10,000 hours time-inservice (TIS) to 12,163 hours TIS. The manufacturer requests the compliance time for initial replacement be increased from ‘‘upon the accumulation of 10,000 TIS or within the next 100 hours TIS after the effective date of the AD, whichever occurs later,’’ to ‘‘upon the accumulation of 10,000 TIS or within the next 500 hours TIS after the effective date of the AD, whichever occurs later.’’ We partially agree with the commenter. Since there have not been any reported cracks on the above referenced crew seat bucket assemblies and there is confidence from the manufacturer that there is a 2,163-hour TIS ‘‘cushion,’’ we agree that increasing 19999 the threshold compliance time from 100 hours TIS to 500 hours TIS can be done without compromising the safety of crew seat bucket assemblies with 10,000 hours or less TIS. For crew seat bucket assemblies with more than 10,000 hours TIS, we have established a compliance time for initial replacement of 100 hours TIS or upon the accumulation of 10,500 hours TIS, whichever occurs later. We will change the final rule AD action to reflect this change. 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 incorporating the concerns addressed by the commenter and minor editorial corrections. We have determined that we should incorporate the concerns addressed by the commenter, and that these minor changes: —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. Cost of Compliance We estimate that this AD affects 260 airplanes in the U.S. registry. We estimate the following costs to do the replacement: Labor cost Parts cost Total cost per airplane Total cost on U.S. operators 3 workhours × $65 per hour = $195 per seat bucket assembly. $600 per seat bucket assembly. 2 seats on each airplane. $195 + $600 = $795 per seat bucket assembly. $795 per seat bucket assembly × 2 per airplane = $1,590. $1,590 × 260 = $413,400. rmajette on PROD1PC67 with RULES1 Authority for This Rulemaking Regulatory Findings 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. 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 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 VerDate Aug<31>2005 15:12 Apr 18, 2006 Jkt 208001 PO 00000 Frm 00015 Fmt 4700 Sfmt 4700 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–2004–19220; Directorate Identifier 2004–CE–27–AD’’ in your request. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, 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 PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: I E:\FR\FM\19APR1.SGM 19APR1 20000 Federal Register / Vol. 71, No. 75 / Wednesday, April 19, 2006 / Rules and Regulations Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. FAA amends § 39.13 by adding the following new AD: I 2006–08–11 Pilatus Aircraft Ltd.: Amendment 39–14568; Docket No. FAA–2004–19220; Directorate Identifier 2004–CE–27–AD. Effective Date (a) This AD becomes effective on June 2, 2006. Affected ADs (b) None. Applicability (c) This AD affects Models PC–12 and PC– 12/45 airplanes, all serial numbers, that are equipped with the following crew seat bucket assemblies and are certificated in any category: (1) Crew seats with a recline system, part numbers (P/N): 959.30.01.111, 959.30.01.112, 959.30.01.121, and 959.30.01.122 (2) Crew seats without recline system, P/ Ns: 959.30.01.131, 959.30.01.132, 959.30.01.133, and 959.30.01.134 Unsafe Condition (d) This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified in this AD are intended to prevent cracks in the backrest tubes of certain crew seat bucket assemblies, which could result in failure of the seat system. This failure could lead to the pilot and co-pilot’s reduced ability to control the airplane. This failure could also affect the proper function of the seat restrain system in the case of an emergency landing. Compliance (e) To address this problem, you must do the following: Actions Compliance Procedures (1) For crew seat bucket assemblies with a recline system, P/Ns 959.30.01.111, 959.30.01.112, 959.30.01.121, and 959.30.01.122 (or FAA-approved equivalent P/Ns), replace the backrest tubes. Initially replace upon the accumulation of 5,000 hours time-in-service (TIS) or within the next 100 hours TIS after June 2, 2006 (the effective date of this AD), whichever occurs later, unless already done. Thereafter, replace the backrest tubes upon the accumulation of 5,000 hours TIS (the life limit established in this AD). Initially replace upon the accumulation of 10,000 hours TIS or within the next 500 hours TIS after June 2, 2006 (the effective date of this AD), whichever occurs later, unless already done. Thereafter, replace the backrest tubes upon the accumulation of 10,000 hours TIS (the life limit established in this AD). Initially upon the accumulation of 10,500 hours TIS or within the next 100 hours TIS after June 2, 2006 (the effective date of this AD), whichever occurs later, unless already done. Thereafter, replace the backrest tubes upon the accumulation of 10,000 hours TIS (the life limit established in this AD). As of June 2, 2006 (the effective date of this AD). The life limits specified in paragraphs (e)(1), (e)(2), and (e)(3) of this AD apply to all parts installed as spares. Replace following the procedures in the applicable component maintenance manual (CMM). Not applicable ................................................................. Not applicable. As of June 2, 2006 (the effective date of this AD) ......... Not applicable. (2) For crew seat bucket assemblies without a recline system, P/Ns 959.30.01.131, 959.30.01.132, 959.30.01.133, and 959.30.01.134 (or FAA-approved equivalent P/Ns), and with less than or equal to 10,000 hours TIS replace the backrest tubes. (3) For crew seat bucket assemblies without a recline system, P/Ns 959.30.01.131, 959.30.01.132, 959.30.01.133, and 959.30.01.134 (or FAA-approved equivalent P/Ns), and with greater than 10,000 hours TIS replace the backrest tubes. rmajette on PROD1PC67 with RULES1 (4) Do not install: .............................................................. (i) Any crew seat bucket assembly with a recline system, P/N 959.30.01.111, 959.30.01.112, 959.30.01.121, and 959.30.01.122, (or FAA-approved equivalent P/Ns), with unknown hours TIS or which has accumulated 5,000 or more hours TIS; or (ii) Any crew seat bucket assembly without a recline system, P/N 959.30.01.131, 959.30.01.132, 959.30.01.133, and 959.30.01.134 (or FAA-approved equivalent P/Ns), with unknown hours TIS or which has accumulated 10,000 or more hours TIS. (5) 14 CFR 21.303 allows for replacement parts through parts manufacturer approval(PMA). The phrase ‘‘or FAA-approved equivalent part number’’ 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. (6) You must contact the type certificate holder any time a modification or repair is done that affects the parts listed in paragraphs (e)(1), (e)(2), (e)(3), and (e)(4) of this AD to determine the effect, if any, the modification or repair may have on the life limits established in this AD. VerDate Aug<31>2005 15:12 Apr 18, 2006 Jkt 208001 PO 00000 Frm 00016 Fmt 4700 Sfmt 4700 E:\FR\FM\19APR1.SGM 19APR1 Replace following the procedures in the CMM. Replace following the procedures in the CMM. Not applicable. Federal Register / Vol. 71, No. 75 / Wednesday, April 19, 2006 / Rules and Regulations Note 1: The FAA recommends that you return all replaced backrest tubes to Pilatus Aircraft Ltd., Structural Analysis Group ECE, Ch–6371 Stans, Switzerland. Include the following information: crew seat P/N and serial number, aircraft manufacturer serial number, aircraft flying hours, number of flights, and replacement date of the replaced backrest tubes. Note 2: Pilatus PC–12 Aircraft Maintenance Manual Revision 17/Interactive Electronic Technical Publication (IETP) Revision 9, Chapter 4, section 04–00–00, references the crew seat bucket assembly replacements. Alternative Methods of Compliance (AMOCs) (f) The Manager, Standards Office, Small Airplane Directorate, FAA, ATTN: Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329–4059; fax: (816) 329–4090, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Related Information (g) Swiss AD Number HB–2005–470, Effective Date: December 30, 2005, also addresses the subject of this AD. Issued in Kansas City, Missouri, on April 12, 2006. Kim Smith, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 06–3725 Filed 4–18–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–23705; Directorate Identifier 2005–NE–45–AD; Amendment 39– 14567; AD 2006–08–10] RIN 2120–AA64 Airworthiness Directives; General Electric Company CT64–820–4 Turboprop Engines Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule; request for comments. rmajette on PROD1PC67 with RULES1 AGENCY: SUMMARY: The FAA is adopting a new airworthiness directive (AD) for General Electric Company (GE) CT64–820–4 turboprop engines with certain part number (P/N) rotating parts. The parts are in the compressor rotor assembly, gas generator turbine rotor assembly, and power turbine rotor assembly that are subject to low-cycle fatigue. This AD requires removing from service these affected rotating parts at reduced VerDate Aug<31>2005 15:12 Apr 18, 2006 Jkt 208001 compliance times. This AD results from the manufacturer’s discovery of cracks in some rotating parts. We are issuing this AD to prevent cracks in the rotating parts that could cause compressor and turbine wheel fracture and uncontained engine failure. An uncontained engine failure could cause possible damage to the airplane. DATES: This AD becomes effective May 24, 2006. ADDRESSES: Use one of the following addresses to comment on this AD: • DOT Docket Web site: Go to https://dms.dot.gov and follow the instructions for sending your comments electronically. • Government-wide rulemaking Web site: Go to https://www.regulations.gov and follow the instructions for sending your comments electronically. • Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL–401, Washington, DC 20590– 0001. • Fax: (202) 493–2251. • Hand Delivery: Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Contact GE Aircraft Engines Customer Support Center, M/D 285, 1 Neumann Way, Evendale, OH 45215, telephone (513) 552–3272; fax (513) 552–3329; email address: GEAE.csc@ae.ge.com, for the service information identified in this AD. FOR FURTHER INFORMATION CONTACT: Anthony W. Cerra Jr., Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone 781– 238–7128; fax 781–238–7199; e-mail address: anthony.cerra@faa.gov. SUPPLEMENTARY INFORMATION: GE has informed us that cracks have been found in certain P/N rotating parts. The manufacturer reported that cracks were found in the outer rim of a stage 1 aft cooling plate, P/N 4022T37P01, installed on the gas generator turbine (GGT) rotor of a military T64 engine. They also found cracks in the sawcut slots of the GGT rear air seals of stage 2 aft cooling plates, P/N 4022T36P01, in the CT64–820–4 engine model and a similar military T64 engine model. There have been at least 13 reports of cracked GGT rear air seals. Investigation by the manufacturer showed that compressor rotor assemblies, GGT rotor assemblies, and power turbine rotor assemblies have small feature locations. A ‘‘small feature’’ location is any rotating PO 00000 Frm 00017 Fmt 4700 Sfmt 4700 20001 hardware feature with drawing radii less than 0.020 inch. Engineering analysis determined that the small feature locations and other life-limited locations of the rotating parts identified in this action have levels of stress during engine operation that are higher than originally anticipated and could result in cracks on these parts. This condition, if not corrected, could cause compressor and turbine wheel fracture and uncontained engine failure. An uncontained engine failure could cause possible damage to the airplane. FAA’s Determination and Requirements of This AD Although no airplanes registered in the United States use these engines, the possibility exists that the engines could be used on airplanes that are registered in the United States in the future. The unsafe condition described previously is likely to exist or develop on other GE CT64–820–4 turboprop engines of the same type design. We are issuing this AD to prevent cracks in the rotating parts that could cause compressor and turbine wheel fracture and uncontained engine failure. An uncontained engine failure could cause possible damage to the airplane. This AD requires removing from service these affected life-limited rotating parts at reduced compliance times. FAA’s Determination of the Effective Date Since there are currently no domestic operators of this engine model, notice and opportunity for public comment before issuing this AD are unnecessary. A situation exists that allows the immediate adoption of this regulation. Comments Invited This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to send us any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include ‘‘AD Docket No. FAA–2006–23705; Directorate Identifier 2005–NE–45–AD’’ in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it. We will post all comments we receive, without change, to https://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of the DMS Web site, E:\FR\FM\19APR1.SGM 19APR1

Agencies

[Federal Register Volume 71, Number 75 (Wednesday, April 19, 2006)]
[Rules and Regulations]
[Pages 19998-20001]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-3725]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19220; Directorate Identifier 2004-CE-27-AD; 
Amendment 39-14568; AD 2006-08-11]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and 
PC-12/45 Airplanes

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

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 airplanes equipped with 
certain crew seat bucket assemblies with and without a backrest recline 
system. This AD requires you to replace the backrest tubes on these 
crew seat bucket assemblies at a specified time and adds a life limit 
for these backrest tubes. This AD results from mandatory continuing 
airworthiness information (MCAI) issued by the airworthiness authority 
for Switzerland. We are issuing this AD to prevent cracks in the 
backrest tubes of certain crew seat bucket assemblies, which could 
result in failure of the seat system. This failure could lead to the 
pilot and co-pilot's reduced ability to control the airplane. This 
failure could also affect the proper function of the seat restrain 
system in the case of an emergency landing.

DATES: This AD becomes effective on June 2, 2006.

ADDRESSES: For information identified in this AD, contact Pilatus 
Aircraft Ltd., Customer Support Manager, CH-6371 Stans, Switzerland; 
telephone: +41 41 619 6208; fax: +41 41 619 7311; or Pilatus Business 
Aircraft Ltd., Product Support Department, 11755 Airport Way, 
Broomfield, Colorado 80021; telephone: (303) 465-9099; fax: (303) 465-
6040.
    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 20590-0001 or on the Internet at https://
dms.dot.gov. The docket number is FAA-2004-19220; Directorate 
Identifier 2004-CE-27-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; fax: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Discussion

    On February 7, 2006, we issued a proposal to amend part 39 of the 
Federal Aviation Regulations (14 CFR part 39) to include an 
airworthiness directive (AD) that would apply to all Pilatus Aircraft 
Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes equipped with 
certain crew seat bucket assemblies with and without a backrest recline 
system. This proposal

[[Page 19999]]

was published in the Federal Register as a notice of proposed 
rulemaking (NPRM) on February 14, 2006 (71 FR 7698). The NPRM proposed 
to require you to replace the backrest tubes on certain crew seat 
bucket assemblies at a specified time and add a life limit for the 
backrest tubes.

Comments

    We provided the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and FAA's response to each comment:

Comment Issue No. 1: Remove Reference to PC12 Maintenance Manual 
Temporary Revision No. 04-13, Dated June 15, 2005

    The manufacturer states that PC-12 Interactive Electronic Technical 
Publication (IETP) Revision 9 (which will include Aircraft Maintenance 
Manual (AMM) Revision 17) will supersede PC12 Maintenance Manual 
Temporary Revision No. 04-13, dated June 15, 2005, by March 31, 2006, 
by incorporating the information into the IETP.
    The commenter requests to remove the reference to PC12 Maintenance 
Manual Temporary Revision No. 04-13, dated June 15, 2005, from the 
final rule AD action.
    We agree with the commenter and will change the final rule AD 
action.

Comment Issue No. 2: Change the Compliance Time for Replacing Certain 
Crew Seat Bucket Assemblies

    The manufacturer states the life limit and the compliance time for 
replacing crew seat bucket assemblies without a recline system, part 
numbers (P/Ns) 959.30.01.131, 959.30.01.132, 959.30.01.133, and 
959.30.01.134 (or FAA-approved equivalent P/Ns), is too conservative. 
The manufacturer states there have not been any of these seats found 
with cracks and they have confidence the life limit could be increased 
from 10,000 hours time-in-service (TIS) to 12,163 hours TIS.
    The manufacturer requests the compliance time for initial 
replacement be increased from ``upon the accumulation of 10,000 TIS or 
within the next 100 hours TIS after the effective date of the AD, 
whichever occurs later,'' to ``upon the accumulation of 10,000 TIS or 
within the next 500 hours TIS after the effective date of the AD, 
whichever occurs later.''
    We partially agree with the commenter. Since there have not been 
any reported cracks on the above referenced crew seat bucket assemblies 
and there is confidence from the manufacturer that there is a 2,163-
hour TIS ``cushion,'' we agree that increasing the threshold compliance 
time from 100 hours TIS to 500 hours TIS can be done without 
compromising the safety of crew seat bucket assemblies with 10,000 
hours or less TIS. For crew seat bucket assemblies with more than 
10,000 hours TIS, we have established a compliance time for initial 
replacement of 100 hours TIS or upon the accumulation of 10,500 hours 
TIS, whichever occurs later.
    We will change the final rule AD action to reflect this change.

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 incorporating the concerns addressed by the commenter and 
minor editorial corrections. We have determined that we should 
incorporate the concerns addressed by the commenter, and that these 
minor changes:

--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.

Cost of Compliance

    We estimate that this AD affects 260 airplanes in the U.S. 
registry.
    We estimate the following costs to do the replacement:

----------------------------------------------------------------------------------------------------------------
                                                                                            Total cost on U.S.
              Labor cost                      Parts cost        Total cost per airplane         operators
----------------------------------------------------------------------------------------------------------------
3 workhours x $65 per hour = $195 per  $600 per seat bucket     $195 + $600 = $795 per   $795 per seat bucket
 seat bucket assembly.                  assembly. 2 seats on     seat bucket assembly.    assembly x 2 per
                                        each airplane.                                    airplane = $1,590.
                                                                                          $1,590 x 260 =
                                                                                          $413,400.
----------------------------------------------------------------------------------------------------------------

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
    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-2004-19220; Directorate Identifier 2004-CE-27-AD'' in your 
request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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:


[[Page 20000]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. FAA amends Sec.  39.13 by adding the following new AD:

2006-08-11 Pilatus Aircraft Ltd.: Amendment 39-14568; Docket No. 
FAA-2004-19220; Directorate Identifier 2004-CE-27-AD.

Effective Date

    (a) This AD becomes effective on June 2, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD affects Models PC-12 and PC-12/45 airplanes, all 
serial numbers, that are equipped with the following crew seat 
bucket assemblies and are certificated in any category:
    (1) Crew seats with a recline system, part numbers (P/N): 
959.30.01.111, 959.30.01.112, 959.30.01.121, and 959.30.01.122
    (2) Crew seats without recline system, P/Ns: 959.30.01.131, 
959.30.01.132, 959.30.01.133, and 959.30.01.134

Unsafe Condition

    (d) This AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland. The actions specified in this AD are intended to 
prevent cracks in the backrest tubes of certain crew seat bucket 
assemblies, which could result in failure of the seat system. This 
failure could lead to the pilot and co-pilot's reduced ability to 
control the airplane. This failure could also affect the proper 
function of the seat restrain system in the case of an emergency 
landing.

Compliance

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

------------------------------------------------------------------------
            Actions                   Compliance           Procedures
------------------------------------------------------------------------
(1) For crew seat bucket        Initially replace upon  Replace
 assemblies with a recline       the accumulation of     following the
 system, P/Ns 959.30.01.111,     5,000 hours time-in-    procedures in
 959.30.01.112, 959.30.01.121,   service (TIS) or        the applicable
 and 959.30.01.122 (or FAA-      within the next 100     component
 approved equivalent P/Ns),      hours TIS after June    maintenance
 replace the backrest tubes.     2, 2006 (the            manual (CMM).
                                 effective date of
                                 this AD), whichever
                                 occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 5,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(2) For crew seat bucket        Initially replace upon  Replace
 assemblies without a recline    the accumulation of     following the
 system, P/Ns 959.30.01.131,     10,000 hours TIS or     procedures in
 959.30.01.132, 959.30.01.133,   within the next 500     the CMM.
 and 959.30.01.134 (or FAA-      hours TIS after June
 approved equivalent P/Ns),      2, 2006 (the
 and with less than or equal     effective date of
 to 10,000 hours TIS replace     this AD), whichever
 the backrest tubes.             occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 10,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(3) For crew seat bucket        Initially upon the      Replace
 assemblies without a recline    accumulation of         following the
 system, P/Ns 959.30.01.131,     10,500 hours TIS or     procedures in
 959.30.01.132, 959.30.01.133,   within the next 100     the CMM.
 and 959.30.01.134 (or FAA-      hours TIS after June
 approved equivalent P/Ns),      2, 2006 (the
 and with greater than 10,000    effective date of
 hours TIS replace the           this AD), whichever
 backrest tubes.                 occurs later, unless
                                 already done.
                                 Thereafter, replace
                                 the backrest tubes
                                 upon the accumulation
                                 of 10,000 hours TIS
                                 (the life limit
                                 established in this
                                 AD).
(4) Do not install:...........  As of June 2, 2006      Not applicable.
                                 (the effective date
                                 of this AD). The life
                                 limits specified in
                                 paragraphs (e)(1),
                                 (e)(2), and (e)(3) of
                                 this AD apply to all
                                 parts installed as
                                 spares.
    (i) Any crew seat bucket
     assembly with a recline
     system, P/N
     959.30.01.111,
     959.30.01.112,
     959.30.01.121, and
     959.30.01.122, (or FAA-
     approved equivalent P/
     Ns), with unknown hours
     TIS or which has
     accumulated 5,000 or more
     hours TIS; or
    (ii) Any crew seat bucket
     assembly without a
     recline system, P/N
     959.30.01.131,
     959.30.01.132,
     959.30.01.133, and
     959.30.01.134 (or FAA-
     approved equivalent P/
     Ns), with unknown hours
     TIS or which has
     accumulated 10,000 or
     more hours TIS.
(5) 14 CFR 21.303 allows for    Not applicable........  Not applicable.
 replacement parts through
 parts manufacturer
 approval(PMA). The phrase
 ``or FAA-approved equivalent
 part number'' 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.
(6) You must contact the type   As of June 2, 2006      Not applicable.
 certificate holder any time a   (the effective date
 modification or repair is       of this AD).
 done that affects the parts
 listed in paragraphs (e)(1),
 (e)(2), (e)(3), and (e)(4) of
 this AD to determine the
 effect, if any, the
 modification or repair may
 have on the life limits
 established in this AD.
------------------------------------------------------------------------



[[Page 20001]]

     Note 1: The FAA recommends that you return all replaced 
backrest tubes to Pilatus Aircraft Ltd., Structural Analysis Group 
ECE, Ch-6371 Stans, Switzerland. Include the following information: 
crew seat P/N and serial number, aircraft manufacturer serial 
number, aircraft flying hours, number of flights, and replacement 
date of the replaced backrest tubes.


    Note 2: Pilatus PC-12 Aircraft Maintenance Manual Revision 17/
Interactive Electronic Technical Publication (IETP) Revision 9, 
Chapter 4, section 04-00-00, references the crew seat bucket 
assembly replacements.

Alternative Methods of Compliance (AMOCs)

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

Related Information

    (g) Swiss AD Number HB-2005-470, Effective Date: December 30, 
2005, also addresses the subject of this AD.

    Issued in Kansas City, Missouri, on April 12, 2006.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 06-3725 Filed 4-18-06; 8:45 am]
BILLING CODE 4910-13-P
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