Airworthiness Directives; Boeing Model 777-200 and 777-300 Series Airplanes, 6687-6691 [E6-1767]

Download as PDF Federal Register / Vol. 71, No. 27 / Thursday, February 9, 2006 / Proposed Rules 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 the proposed regulation: 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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES § 39.13 section for a location to examine the regulatory evaluation. 6687 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Mitsubishi Heavy Industries: Docket No. FAA–2006–23644; Directorate Identifier 2006–CE–03–AD. Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows: When Is the Last Date I Can Submit Comments on This Proposed AD? (a) The Federal Aviation Administration (FAA) must receive comments on this proposed airworthiness directive (AD) action by March 17, 2006. PART 39—AIRWORTHINESS DIRECTIVES What Other ADs Are Affected by This Action? (b) None. 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Model What Airplanes Are Affected by This AD? (c) This AD affects the following airplane models and serial numbers that are certificated in any category: Serial Nos. (1) MU–2B–26A and MU–2B–40 ........................ (2) MU–2B–36A and MU–2B–60 ........................ What Is the Unsafe Condition Presented in This AD? (d) This AD results from a recent safety evaluation that used a data-driven approach to analyze the design, operation, and maintenance of the MU–2B series airplanes in order to determine their safety and define 321SA, 348SA, 350SA through 419SA, 421SA, 422SA, and 423SA. 661SA, 697SA through 747SA, 749SA through 757SA, and 759SA through 773SA. what steps, if any, are necessary for their safe operation. Part of that evaluation was the identification of unsafe conditions that exist or could develop on the affected type design airplanes. The actions specified in this AD are intended to prevent confusion in blade angle settings. This unsafe condition, if not corrected, could lead to an asymmetric thrust situation in certain flight conditions, which could result in airplane controllability problems. What Must I Do To Address This Problem? (e) To address this problem, you must do the following: Actions Compliance Procedures Change the flight idle blade angle ..................... Within the next 100 hours time-in-service (TIS). Follow Mitsubishi Aircraft International, Inc. Service Bulletin No. SB016/61–001, dated March 18, 1980. wwhite on PROD1PC61 with PROPOSALS May I Request an Alternative Method of Compliance? (f) The Manager, Fort Worth Airplane Certification Office (ACO), FAA, has the authority to approve alternative methods of compliance for this AD, if requested using the procedures found in 14 CFR 39.19. (g) For information on any already approved alternative methods of compliance or for information pertaining to this AD, contact Rao Edupuganti, Aerospace Engineer, Fort Worth ACO, ASW–150, Rotorcraft Directorate, FAA, 2601 Meacham Boulevard, Fort Worth, Texas 76137–4298; telephone: 817–222–5284; facsimile: 817–222–5960. https://dms.dot.gov. The docket number is Docket No. FAA–2006–23644; Directorate Identifier 2006–CE–03–AD. Issued in Kansas City, Missouri, on February 3, 2006. John R. Colomy, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E6–1769 Filed 2–8–06; 8:45 am] 20:19 Feb 08, 2006 Jkt 208001 PO 00000 Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–23842; Directorate Identifier 2005–NM–145–AD] RIN 2120–AA64 Airworthiness Directives; Boeing Model 777–200 and 777–300 Series Airplanes BILLING CODE 4910–13–P Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). AGENCY: May I Get Copies of the Documents Referenced in This AD? (h) To get copies of the documents referenced in this AD, contact Mitsubishi Heavy Industries, Ltd., 4951 Airport Parkway, Suite 800, Addison, Texas 75001 telephone: 972–934–5480; facsimile: 972– 934–5488. 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, or on the Internet at VerDate Aug<31>2005 DEPARTMENT OF TRANSPORTATION SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 777–200 and 777– 300 series airplanes. This proposed AD would require repetitive inspections for discrepancies of the splined Frm 00007 Fmt 4702 Sfmt 4702 E:\FR\FM\09FEP1.SGM 09FEP1 wwhite on PROD1PC61 with PROPOSALS 6688 Federal Register / Vol. 71, No. 27 / Thursday, February 9, 2006 / Proposed Rules components that support the inboard end of the inboard trailing edge flap, and related investigative, corrective, and other specified actions if necessary. This proposed AD would also require a onetime modification of the inboard support of the inboard trailing edge flap by installing a new isolation strap and attachment hardware. This proposed AD would also require repetitive replacement of the torque tube assembly. This proposed AD results from reports of corrosion on the torque tube and closeout rib fittings that support the inboard end of the inboard trailing edge flap, as well as a structural reassessment of the torque tube joint that revealed the potential for premature fatigue cracking of the torque tube that would not be detected using reasonable inspection methods. We are proposing this AD to detect and correct corrosion or cracking of the torque tube and closeout rib fittings that support the inboard end of the inboard trailing edge flap. Cracking in these components could lead to a fracture, which could result in loss of the inboard trailing edge flap and consequent reduced controllability of the airplane. DATES: We must receive comments on this proposed AD by March 27, 2006. ADDRESSES: Use one of the following addresses to submit comments on this proposed 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. • 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124–2207, for the service information identified in this proposed AD. FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 917–6443; fax (425) 917–6590. SUPPLEMENTARY INFORMATION: VerDate Aug<31>2005 20:19 Feb 08, 2006 Jkt 208001 Comments Invited We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number ‘‘FAA–2006–23842; Directorate Identifier 2005–NM–145–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments. 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 proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT’s complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477–78), or you may visit https:// dms.dot.gov. Examining the Docket You may examine the AD docket on the Internet at https://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647–5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them. Discussion We have received reports that corrosion has been found on the torque tube and closeout rib fitting assembly that support the inboard end of the inboard trailing edge flap on certain Boeing Model 777–200 and –300 series airplanes. Investigation has revealed contact between the splined areas of the torque tube and closeout rib fitting, causing wear to the titanium-cadmium plating of the components. When the grease on these components dries out, moisture may enter the area, and corrosion may form in areas where the plating has worn away. This corrosion may subsequently lead to corrosion PO 00000 Frm 00008 Fmt 4702 Sfmt 4702 pitting and cracking that can propagate by stress corrosion. Also, a structural reassessment of Boeing Model 777–200 and 777–300 series airplanes revealed the potential for premature fatigue cracking of the torque tube of the inboard trailing edge flap, whether or not the torque tube is corroded. This premature fatigue cracking would not be detected by traditional inspection methods such as visual or nondestructive inspection techniques. Cracking of the torque tube or closeout rib fitting, if not corrected, could lead to a fracture of the torque tube or a closeout rib fitting, which could result in loss of the inboard trailing edge flap and consequent reduced controllability of the airplane. Relevant Service Information We have reviewed Boeing Service Bulletin 777–57A0048, Revision 1, dated June 9, 2005. The service bulletin describes procedures for performing repetitive detailed inspections for any discrepancy of the splined components (torque tube, closeout rib fitting, carrier beam pillow block fitting assembly (i.e., the matched set of two carrier beam pillow block fittings) and the drive crank support) that support the inboard end of the inboard trailing edge flap. Discrepancies of the torque tube and closeout rib fitting include light contact wear, corrosion pits, corrosion, cracking, and fracture. Discrepancies of the other splined components consist of damage to the cadmium plating. (The carrier beam pillow block fitting assembly and drive crank support are made from corrosion-resistant steel. The condition of the plating on these components must be inspected because the plating helps to protect these components from the steel torque tube, which is made of less corrosionresistant 4330M steel.) If no discrepancy is found, the service bulletin describes procedures for other specified actions that include: • Assembling the splined components with corrosion-inhibiting compound. • Modifying certain splined components by installing a new isolation strap and attachment hardware. (Installing the isolation strap is intended to prevent a washer installed between the drive crank support and the carrier beam pillow block fittings from coming into contact with the torque tube splines, which could damage the finish on the torque tube splines.) • Refinishing the components as necessary. E:\FR\FM\09FEP1.SGM 09FEP1 6689 Federal Register / Vol. 71, No. 27 / Thursday, February 9, 2006 / Proposed Rules If a discrepancy is found, the service bulletin describes procedures for corrective actions that include: • Determining the condition of the spline interface by doing an evaluation of the level of spline rework using the guidelines in Appendix A of the service bulletin. • Blending out light contact wear (defined in the service bulletin as shallow surface irregularities or discrete pits, which can be blended out using unpowered hand tools). • Reworking corroded or corrosionpitted components according to the Spline Rework procedures in Part 3 of the service bulletin if the damage is within specified limits. • Replacing corroded or corrosionpitted components having damage that is outside the specified limits with new or serviceable components. • Replacing cracked or fractured components with new or serviceable components. (The service bulletin notes that, if one of the two fittings that make up the closeout rib fitting assembly or the carrier beam pillow block fitting assembly is replaced, both fittings that make up the assembly must be replaced at the same time.) • Refinishing components as necessary. If spline rework is accomplished, the service bulletin also describes procedures for performing additional investigative actions that include: • Evaluating the interfaces between the splined components using the Spline Rework Evaluation or the Preliminary Spline Rework Evaluation procedure, as applicable. • Doing a magnetic particle inspection of the splined area for cracking. • Doing a detailed inspection for corrosion or corrosion pitting to ensure complete removal of corrosion or corrosion pitting. • Doing a detailed inspection for discoloration due to overheating, or a local surface temper etch inspection for other damage, that may have resulted from performing the rework procedures. The service bulletin specifies a compliance time for the initial inspection of 48 months after the date of issuance of the original Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness, or within 24 months after the date of Revision 1 of the service bulletin, whichever is later. The service bulletin specifies repeating the detailed inspections for any discrepancy of the splined components that support the inboard end of the inboard trailing edge flap within 5 years or 10 years, depending on the condition of the splined components. (Subsequent inspections are required at intervals not to exceed 5 years or 10 years, depending on the condition found during the repeat inspection.) If the criteria for Condition D are met during the initial inspection (as determined by the spline evaluation), a repeat inspection is required within 24 months. If the criteria for Condition C or D are met in a subsequent repeat inspection, the affected splined component must be replaced before further flight. Note (c) of Table 7, under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin also specifies repetitively replacing the torque tube assembly with a new torque tube assembly, regardless of condition. The service bulletin specifies an initial compliance time for this replacement of either 18,000 or 20,000 total flight cycles on the airplane (depending on airplane group), or 24 months after the date of Revision 1 of the service bulletin, whichever is later. The repetitive interval for the replacement is either 18,000 or 20,000 flight cycles, depending on airplane group. FAA’s Determination and Requirements of the Proposed AD We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed below under ‘‘Difference Between Proposed AD and Service Information.’’ Difference Between Proposed AD and Service Information The service bulletin specifies compliance times relative to the date of issuance of the service bulletin; however, this proposed AD would require compliance before the specified compliance time after the effective date of this AD. Clarification of Requirement To Replace Torque Tube Assembly As explained previously, Note (c) of Table 7, under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin specifies repetitively replacing the torque tube assembly with a new torque tube assembly, regardless of condition. However, this replacement of a torque tube assembly with no discrepancy is not specified in the Accomplishment Instructions of the service bulletin. Paragraph (k) of this proposed AD would require the repetitive replacement of the torque tube assembly at the schedule indicated in the Compliance section of the service bulletin. Interim Action We consider this proposed AD interim action. The manufacturer is currently developing a new, improved torque tube that will be made from corrosion-resistant steel and have thicker walls. Installing this new, improved torque tube is expected to address the unsafe condition identified in this proposed AD and eliminate the need for the repetitive inspections and torque tube assembly replacements that would be required by this proposed AD. Once the improved torque tube is developed, approved, and available, we may consider additional rulemaking to require installing it. Costs of Compliance There are about 353 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD, at an average labor rate of $65 per work hour. ESTIMATED COSTS wwhite on PROD1PC61 with PROPOSALS Action Work hours Parts Cost per airplane Detailed inspection for discrepancies of the splined components. Modification (Installing isolation strap and hardware). 20 ................. None ........ Negligible ..... $17,156 ... Number of U.S.-registered airplanes $1,300, per inspection cycle. $17,156 ....................... VerDate Aug<31>2005 20:19 Feb 08, 2006 Jkt 208001 PO 00000 Frm 00009 Fmt 4702 Sfmt 4702 E:\FR\FM\09FEP1.SGM 132 132 09FEP1 Fleet cost $171,600, per inspection cycle. $2,264,592. 6690 Federal Register / Vol. 71, No. 27 / Thursday, February 9, 2006 / Proposed Rules ESTIMATED COSTS—Continued Action Work hours Parts Cost per airplane Replacement of torque tube assembly ............. Negligible 1 ... $24,230 ... $24,230 ....................... 1 Provided Regulatory Findings We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation: 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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. VerDate Aug<31>2005 132 Fleet cost $3,198,360, per replacement cycle. that the replacement is performed at the same time as a scheduled inspection. 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 rulemaking action. wwhite on PROD1PC61 with PROPOSALS Number of U.S.-registered airplanes 20:19 Feb 08, 2006 Jkt 208001 The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. § 39.13 [Amended] 2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD): Boeing: Docket No. FAA–2006–23842; Directorate Identifier 2005–NM–145–AD. Comments Due Date (a) The FAA must receive comments on this AD action by March 27, 2006. Affected ADs (b) None. Applicability (c) This AD applies to Boeing Model 777– 200 and –300 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 777–57A0048, Revision 1, dated June 9, 2005. Unsafe Condition (d) This AD results from reports of corrosion on the torque tube and closeout rib fittings that support the inboard end of the inboard trailing edge flap, as well as a structural reassessment of the torque tube joint that revealed the potential for premature fatigue cracking of the torque tube that would not be detected using reasonable inspection methods. We are issuing this AD to detect and correct corrosion or cracking of the torque tube and closeout rib fittings that support the inboard end of the inboard trailing edge flap. Cracking in these components could lead to a fracture, which could result in loss of the inboard trailing edge flap and consequent reduced controllability of the airplane. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. PO 00000 Frm 00010 Fmt 4702 Sfmt 4702 Service Bulletin Reference (f) The term ‘‘service bulletin,’’ as used in this AD, means Boeing Service Bulletin 777– 57A0048, Revision 1, dated June 9, 2005. (g) Where the service bulletin specifies a compliance time after the issuance of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. Initial Inspection (h) Do a detailed inspection for any discrepancy of the splined components of the inboard trailing edge flap, in accordance with the Accomplishment Instructions of the service bulletin. The splined components of the inboard trailing edge flap include the torque tube, closeout rib fitting assembly, carrier beam pillow block fitting assembly, and drive crank support. Discrepancies of the torque tube and closeout rib fitting include light contact wear, corrosion pits, corrosion, cracking, or fracture. Discrepancies of the carrier beam pillow block fitting assembly and drive crank support consist of light contact wear and damage to the cadmium plating. Do the initial inspection at the applicable time specified in Table 7 under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin, except as provided by paragraph (g) of this AD. No Discrepancy/Other Specified Actions (i) If no discrepancy is found, perform all applicable specified actions, including the modification to install a new isolation strap and attachment hardware, in accordance with the Accomplishment Instructions of the service bulletin. Then, repeat the inspection at the applicable time specified in Table 7 under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin. Related Investigative/Corrective/Other Specified Actions and Repetitive Inspections (j) For any discrepancy found during any inspection required by this AD: Before further flight, accomplish all applicable investigative, corrective, and other specified actions, including the modification to install a new isolation strap and attachment hardware, in accordance with the Accomplishment Instructions of the service bulletin. Then, evaluate the spline rework to determine the appropriate repetitive interval, in accordance with the Accomplishment Instructions of the service bulletin. Thereafter, repeat the inspection at the applicable interval specified in Table 7 under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin. Replacement of Torque Tube Assembly (k) Replace the torque tube assembly with a new torque tube assembly, in accordance E:\FR\FM\09FEP1.SGM 09FEP1 Federal Register / Vol. 71, No. 27 / Thursday, February 9, 2006 / Proposed Rules with the Accomplishment Instructions of the service bulletin. Do the initial replacement at the applicable compliance time specified in Notes (c) and (d), as applicable, of Table 7 in paragraph 1.E., ‘‘Compliance,’’ of the service bulletin, except as provided by paragraph (g) of this AD. Repeat the replacement thereafter at the applicable interval specified in Notes (c) and (d), as applicable, of Table 7 under paragraph 1.E., ‘‘Compliance,’’ of the service bulletin. Alternative Methods of Compliance (AMOCs) (l)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. (3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane. Issued in Renton, Washington, on January 31, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E6–1767 Filed 2–8–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 99–NE–12–AD] RIN 2120–AA64 Airworthiness Directives; Turbomeca Turmo IV A and IV C Series Turboshaft Engines Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). wwhite on PROD1PC61 with PROPOSALS AGENCY: SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) for Turbomeca Turmo IV A and IV C series turboshaft engines. That AD currently requires borescope and eddy current inspections or ultrasonic inspections of centrifugal compressor intake wheel blades for cracks and evidence of corrosion pitting, and replacement with serviceable parts. This proposed AD would require the VerDate Aug<31>2005 20:19 Feb 08, 2006 Jkt 208001 same actions, but would require borescope inspections at more frequent intervals for certain engines. This proposed AD results from Turbomeca’s review of the engines’ service experience that determined more frequent borescope inspections are required on engines not modified to the TU 191, TU 197, or TU 224 standard. We are proposing this AD to prevent centrifugal compressor intake wheel blade cracks, which can result in engine in-flight power loss, engine shutdown, or forced landing. DATES: We must receive any comments on this proposed AD by April 10, 2006. ADDRESSES: Use one of the following addresses to comment on this proposed AD: • By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99–NE–12– AD, 12 New England Executive Park, Burlington, MA 01803–5299. • By fax: (781) 238–7055. • By e-mail: 9-aneadcomment@faa.gov. You can get the service information identified in this proposed AD from Turbomeca, 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15. You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA. FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803–5299; telephone (781) 238–7175; fax (781) 238–7199. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include ‘‘AD Docket No. 99– NE–12–AD’’ in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will datestamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We PO 00000 Frm 00011 Fmt 4702 Sfmt 4702 6691 will consider all comments received by the closing date and may amend the proposed AD in light of those comments. Examining the AD Docket You may examine the AD Docket (including any comments and serviceinformation), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location. Discussion On May 20, 2003, the FAA issued AD 2003–11–09, Amendment 39–13168 (68 FR 31970, May 29, 2003). That AD requires initial and repetitive borescope and eddy current inspections or ultrasonic inspections of centrifugal compressor intake wheel blades for cracks and evidence of corrosion pitting, and, if found cracked or if there is evidence of corrosion pitting, replacement with serviceable parts. The Direction Generale de L’Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Turbomeca Turmo IV A and IV C series turboshaft engines. The DGAC advises that they have received reports of cracked centrifugal compressor intake wheel blades. The phenomena of blade cracking occurs in two phases; initiation after a single event, such as foreign object damage or surge, and crack propagation due to operating at a gas generator speed, between 80 percent and 83 percent, which sets up a vibration. Although the exact cause of the initiation of cracks has not yet been identified, cracks could initiate at corrosion pits. The investigation is continuing. This condition, if not corrected, could result in centrifugal compressor intake wheel blade cracks, which can result in engine in-flight power loss, engine shutdown, or forced landing. Since AD 2003–11–09 required the removal of the TU 197 standard within 6 months after the AD’s effective date of July 3, 2003, the TU 197 standard is no longer allowed. The compliance time in this proposed AD requires removing the TU 197 standard before further flight. Actions Since AD 2003–11–09 Was Issued Since AD 2003–11–09 was issued, Turbomeca reevaluated the engines’ service experience and reduced the borescope inspection interval for engines not modified to the TU 191, TU 197, or TU 224 standard, from 250 flight hours-since-last inspection to 200 flight hours-since-last inspection. Also, E:\FR\FM\09FEP1.SGM 09FEP1

Agencies

[Federal Register Volume 71, Number 27 (Thursday, February 9, 2006)]
[Proposed Rules]
[Pages 6687-6691]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-1767]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23842; Directorate Identifier 2005-NM-145-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 and 777-300 Series 
Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 777-200 and 777-300 series airplanes. This 
proposed AD would require repetitive inspections for discrepancies of 
the splined

[[Page 6688]]

components that support the inboard end of the inboard trailing edge 
flap, and related investigative, corrective, and other specified 
actions if necessary. This proposed AD would also require a one-time 
modification of the inboard support of the inboard trailing edge flap 
by installing a new isolation strap and attachment hardware. This 
proposed AD would also require repetitive replacement of the torque 
tube assembly. This proposed AD results from reports of corrosion on 
the torque tube and closeout rib fittings that support the inboard end 
of the inboard trailing edge flap, as well as a structural reassessment 
of the torque tube joint that revealed the potential for premature 
fatigue cracking of the torque tube that would not be detected using 
reasonable inspection methods. We are proposing this AD to detect and 
correct corrosion or cracking of the torque tube and closeout rib 
fittings that support the inboard end of the inboard trailing edge 
flap. Cracking in these components could lead to a fracture, which 
could result in loss of the inboard trailing edge flap and consequent 
reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by March 27, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed 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.
     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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6443; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
23842; Directorate Identifier 2005-NM-145-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    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 proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit https://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at https://
dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    We have received reports that corrosion has been found on the 
torque tube and closeout rib fitting assembly that support the inboard 
end of the inboard trailing edge flap on certain Boeing Model 777-200 
and -300 series airplanes. Investigation has revealed contact between 
the splined areas of the torque tube and closeout rib fitting, causing 
wear to the titanium-cadmium plating of the components. When the grease 
on these components dries out, moisture may enter the area, and 
corrosion may form in areas where the plating has worn away. This 
corrosion may subsequently lead to corrosion pitting and cracking that 
can propagate by stress corrosion. Also, a structural reassessment of 
Boeing Model 777-200 and 777-300 series airplanes revealed the 
potential for premature fatigue cracking of the torque tube of the 
inboard trailing edge flap, whether or not the torque tube is corroded. 
This premature fatigue cracking would not be detected by traditional 
inspection methods such as visual or non-destructive inspection 
techniques. Cracking of the torque tube or closeout rib fitting, if not 
corrected, could lead to a fracture of the torque tube or a closeout 
rib fitting, which could result in loss of the inboard trailing edge 
flap and consequent reduced controllability of the airplane.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 777-57A0048, Revision 1, 
dated June 9, 2005. The service bulletin describes procedures for 
performing repetitive detailed inspections for any discrepancy of the 
splined components (torque tube, closeout rib fitting, carrier beam 
pillow block fitting assembly (i.e., the matched set of two carrier 
beam pillow block fittings) and the drive crank support) that support 
the inboard end of the inboard trailing edge flap. Discrepancies of the 
torque tube and closeout rib fitting include light contact wear, 
corrosion pits, corrosion, cracking, and fracture. Discrepancies of the 
other splined components consist of damage to the cadmium plating. (The 
carrier beam pillow block fitting assembly and drive crank support are 
made from corrosion-resistant steel. The condition of the plating on 
these components must be inspected because the plating helps to protect 
these components from the steel torque tube, which is made of less 
corrosion-resistant 4330M steel.)
    If no discrepancy is found, the service bulletin describes 
procedures for other specified actions that include:
     Assembling the splined components with corrosion-
inhibiting compound.
     Modifying certain splined components by installing a new 
isolation strap and attachment hardware. (Installing the isolation 
strap is intended to prevent a washer installed between the drive crank 
support and the carrier beam pillow block fittings from coming into 
contact with the torque tube splines, which could damage the finish on 
the torque tube splines.)
     Refinishing the components as necessary.

[[Page 6689]]

    If a discrepancy is found, the service bulletin describes 
procedures for corrective actions that include:
     Determining the condition of the spline interface by doing 
an evaluation of the level of spline rework using the guidelines in 
Appendix A of the service bulletin.
     Blending out light contact wear (defined in the service 
bulletin as shallow surface irregularities or discrete pits, which can 
be blended out using unpowered hand tools).
     Reworking corroded or corrosion-pitted components 
according to the Spline Rework procedures in Part 3 of the service 
bulletin if the damage is within specified limits.
     Replacing corroded or corrosion-pitted components having 
damage that is outside the specified limits with new or serviceable 
components.
     Replacing cracked or fractured components with new or 
serviceable components. (The service bulletin notes that, if one of the 
two fittings that make up the closeout rib fitting assembly or the 
carrier beam pillow block fitting assembly is replaced, both fittings 
that make up the assembly must be replaced at the same time.)
     Refinishing components as necessary.
    If spline rework is accomplished, the service bulletin also 
describes procedures for performing additional investigative actions 
that include:
     Evaluating the interfaces between the splined components 
using the Spline Rework Evaluation or the Preliminary Spline Rework 
Evaluation procedure, as applicable.
     Doing a magnetic particle inspection of the splined area 
for cracking.
     Doing a detailed inspection for corrosion or corrosion 
pitting to ensure complete removal of corrosion or corrosion pitting.
     Doing a detailed inspection for discoloration due to 
overheating, or a local surface temper etch inspection for other 
damage, that may have resulted from performing the rework procedures.
    The service bulletin specifies a compliance time for the initial 
inspection of 48 months after the date of issuance of the original 
Airworthiness Certificate or the date of issuance of the original 
Export Certificate of Airworthiness, or within 24 months after the date 
of Revision 1 of the service bulletin, whichever is later. The service 
bulletin specifies repeating the detailed inspections for any 
discrepancy of the splined components that support the inboard end of 
the inboard trailing edge flap within 5 years or 10 years, depending on 
the condition of the splined components. (Subsequent inspections are 
required at intervals not to exceed 5 years or 10 years, depending on 
the condition found during the repeat inspection.) If the criteria for 
Condition D are met during the initial inspection (as determined by the 
spline evaluation), a repeat inspection is required within 24 months. 
If the criteria for Condition C or D are met in a subsequent repeat 
inspection, the affected splined component must be replaced before 
further flight.
    Note (c) of Table 7, under paragraph 1.E., ``Compliance,'' of the 
service bulletin also specifies repetitively replacing the torque tube 
assembly with a new torque tube assembly, regardless of condition. The 
service bulletin specifies an initial compliance time for this 
replacement of either 18,000 or 20,000 total flight cycles on the 
airplane (depending on airplane group), or 24 months after the date of 
Revision 1 of the service bulletin, whichever is later. The repetitive 
interval for the replacement is either 18,000 or 20,000 flight cycles, 
depending on airplane group.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously, except as discussed below under 
``Difference Between Proposed AD and Service Information.''

Difference Between Proposed AD and Service Information

    The service bulletin specifies compliance times relative to the 
date of issuance of the service bulletin; however, this proposed AD 
would require compliance before the specified compliance time after the 
effective date of this AD.

Clarification of Requirement To Replace Torque Tube Assembly

    As explained previously, Note (c) of Table 7, under paragraph 1.E., 
``Compliance,'' of the service bulletin specifies repetitively 
replacing the torque tube assembly with a new torque tube assembly, 
regardless of condition. However, this replacement of a torque tube 
assembly with no discrepancy is not specified in the Accomplishment 
Instructions of the service bulletin. Paragraph (k) of this proposed AD 
would require the repetitive replacement of the torque tube assembly at 
the schedule indicated in the Compliance section of the service 
bulletin.

Interim Action

    We consider this proposed AD interim action. The manufacturer is 
currently developing a new, improved torque tube that will be made from 
corrosion-resistant steel and have thicker walls. Installing this new, 
improved torque tube is expected to address the unsafe condition 
identified in this proposed AD and eliminate the need for the 
repetitive inspections and torque tube assembly replacements that would 
be required by this proposed AD. Once the improved torque tube is 
developed, approved, and available, we may consider additional 
rulemaking to require installing it.

Costs of Compliance

    There are about 353 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD, at an average labor 
rate of $65 per work hour.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                 Number of U.S.-
            Action                Work hours         Parts          Cost per       registered       Fleet cost
                                                                    airplane        airplanes
----------------------------------------------------------------------------------------------------------------
Detailed inspection for        20..............  None.........  $1,300, per                 132  $171,600, per
 discrepancies of the splined                                    inspection                       inspection
 components.                                                     cycle.                           cycle.
Modification (Installing       Negligible......  $17,156......  $17,156........             132  $2,264,592.
 isolation strap and
 hardware).

[[Page 6690]]

 
Replacement of torque tube     Negligible \1\..  $24,230......  $24,230........             132  $3,198,360, per
 assembly.                                                                                        replacement
                                                                                                  cycle.
----------------------------------------------------------------------------------------------------------------
\1\ Provided that the replacement is performed at the same time as a scheduled inspection.

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 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 the proposed 
regulation:
    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 regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-23842; Directorate Identifier 2005-NM-
145-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by March 27, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 and -300 series 
airplanes, certificated in any category, as identified in Boeing 
Service Bulletin 777-57A0048, Revision 1, dated June 9, 2005.

Unsafe Condition

    (d) This AD results from reports of corrosion on the torque tube 
and closeout rib fittings that support the inboard end of the 
inboard trailing edge flap, as well as a structural reassessment of 
the torque tube joint that revealed the potential for premature 
fatigue cracking of the torque tube that would not be detected using 
reasonable inspection methods. We are issuing this AD to detect and 
correct corrosion or cracking of the torque tube and closeout rib 
fittings that support the inboard end of the inboard trailing edge 
flap. Cracking in these components could lead to a fracture, which 
could result in loss of the inboard trailing edge flap and 
consequent reduced controllability of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means 
Boeing Service Bulletin 777-57A0048, Revision 1, dated June 9, 2005.
    (g) Where the service bulletin specifies a compliance time after 
the issuance of the service bulletin, this AD requires compliance 
within the specified compliance time after the effective date of 
this AD.

Initial Inspection

    (h) Do a detailed inspection for any discrepancy of the splined 
components of the inboard trailing edge flap, in accordance with the 
Accomplishment Instructions of the service bulletin. The splined 
components of the inboard trailing edge flap include the torque 
tube, closeout rib fitting assembly, carrier beam pillow block 
fitting assembly, and drive crank support. Discrepancies of the 
torque tube and closeout rib fitting include light contact wear, 
corrosion pits, corrosion, cracking, or fracture. Discrepancies of 
the carrier beam pillow block fitting assembly and drive crank 
support consist of light contact wear and damage to the cadmium 
plating. Do the initial inspection at the applicable time specified 
in Table 7 under paragraph 1.E., ``Compliance,'' of the service 
bulletin, except as provided by paragraph (g) of this AD.

No Discrepancy/Other Specified Actions

    (i) If no discrepancy is found, perform all applicable specified 
actions, including the modification to install a new isolation strap 
and attachment hardware, in accordance with the Accomplishment 
Instructions of the service bulletin. Then, repeat the inspection at 
the applicable time specified in Table 7 under paragraph 1.E., 
``Compliance,'' of the service bulletin.

Related Investigative/Corrective/Other Specified Actions and Repetitive 
Inspections

    (j) For any discrepancy found during any inspection required by 
this AD: Before further flight, accomplish all applicable 
investigative, corrective, and other specified actions, including 
the modification to install a new isolation strap and attachment 
hardware, in accordance with the Accomplishment Instructions of the 
service bulletin. Then, evaluate the spline rework to determine the 
appropriate repetitive interval, in accordance with the 
Accomplishment Instructions of the service bulletin. Thereafter, 
repeat the inspection at the applicable interval specified in Table 
7 under paragraph 1.E., ``Compliance,'' of the service bulletin.

Replacement of Torque Tube Assembly

    (k) Replace the torque tube assembly with a new torque tube 
assembly, in accordance

[[Page 6691]]

with the Accomplishment Instructions of the service bulletin. Do the 
initial replacement at the applicable compliance time specified in 
Notes (c) and (d), as applicable, of Table 7 in paragraph 1.E., 
``Compliance,'' of the service bulletin, except as provided by 
paragraph (g) of this AD. Repeat the replacement thereafter at the 
applicable interval specified in Notes (c) and (d), as applicable, 
of Table 7 under paragraph 1.E., ``Compliance,'' of the service 
bulletin.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane.

    Issued in Renton, Washington, on January 31, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-1767 Filed 2-8-06; 8:45 am]
BILLING CODE 4910-13-P
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