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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2007-27776; Directorate Identifier 2006-NM-170-AD]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT).
 ACTION: Notice of proposed rulemaking (NPRM).
 SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Airbus Model A318-100, A319-100, A320-200, A321-100, and A321-200 series airplanes, and Model A320-111 airplanes. The existing AD currently requires an inspection to determine whether certain braking and steering control units (BSCUs) are installed or have ever been installed. For airplanes on which certain BSCUs are installed or have ever been installed, the existing AD requires an inspection of the nose landing gear (NLG) upper support and corrective action if necessary, and a check of the NLG strut inflation pressure and an adjustment if necessary. For some of these airplanes, the existing AD also requires a revision to the aircraft flight manual to incorporate an operating procedure to recover normal steering in the event of a steering failure. This proposed AD would require repetitive inspections of the NLG upper support, and related investigative/corrective actions in accordance with new service information; and would remove the one-time inspection that was required by the existing AD. This proposed AD also would provide an optional terminating action for the repetitive inspections. This proposed AD results from a report of an incident where an airplane landed with the NLG turned 90 degrees from centerline, and from additional reports of NLG upper support anti-rotation lugs rupturing in service. We are proposing this AD to prevent landings with the NLG turned 90 degrees from centerline, which could result in reduced controllability of the airplane.
 DATES: We must receive comments on this proposed AD by May 7, 2007.
 ADDRESSES: Use one of the following addresses to submit comments on this proposed AD. DOT Docket Web site: Go to*http://dms.dot.gov*
                         and follow the instructions for sending your comments electronically.
                    Government-wide rulemaking Web site: Go to*http://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 Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for service information identified in this proposed AD.
 FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2141; fax (425) 227-1149.


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 “Docket No. FAA-2007-27776; Directorate Identifier 2006-NM-170-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 
                    *http://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 the DOT's complete Privacy Act Statement in the 
                    **Federal Register**
                     published on April 11, 2000 (65 FR 19477-78), or you may visit 
                    *http://dms.dot.gov*. Examining the Docket You may examine the AD docket on the Internet at 
                    *http://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 On November 16, 2005, we issued AD 2005-24-06, amendment 39-14386 (70 FR 70715, November 23, 2005), for all Airbus Model A318-100, A319-100, A320-200, A321-100, and A321-200 series airplanes, and Model A320-111 airplanes. That AD requires an inspection to determine whether certain braking and steering control units (BSCUs) are installed or have ever been installed. For airplanes on which certain BSCUs are installed or have ever been installed, that AD requires an inspection of the nose landing gear (NLG) upper support and corrective action if necessary, and a check of the NLG strut inflation pressure and an adjustment if necessary. For some of these airplanes, that AD also requires a revision to the aircraft flight manual (AFM) to incorporate an operating procedure to recover normal steering in the event of a steering failure. That AD resulted from a report of an incident where an airplane landed with the NLG turned 90 degrees from centerline. We issued that AD to prevent landings with the NLG turned 90 degrees from centerline, which could result in reduced controllability of the airplane. Actions Since Existing AD Was Issued Since we issued AD 2005-24-06, several additional NLG upper support anti-rotation lugs have ruptured in service, which could lead to the inability to retract the NLG and possible landings with the nose wheel turned 90 degrees from centerline. Investigations showed that the affected airplanes were all equipped with enhanced manufacturing and maintainability (EMM) BSCU (Standard L4.1 and L4.5). The NLG shock absorber was also found to be over-pressurized on some of these airplanes, which resulted in increased loads on the upper support. As a result, 
                    ( print page 16750)
                    the manufacturer developed a repetitive boroscope inspection of the NLG upper support lugs and cylinder lugs to replace the one-time inspection, and an optional terminating action for the repetitive inspections. Relevant Service Information Airbus has issued Service Bulletin A320-32-1310, dated February 8, 2006. The service bulletin describes procedures for doing a records review to determine if the airplane is equipped with or has ever been equipped with an EMM BSCU. For those airplanes that are equipped with an EMM BSCU, the service bulletin describes procedures for doing a repetitive special detailed inspection (boroscopic) for broken or cracked NLG upper support lugs and missing cylinder lugs, and related investigative/corrective actions. The related investigative/corrective actions follow: If the upper support anti-rotation lugs are broken or cracked, or if a cylinder lug is missing: Do a pressure check of the NLG shock absorber (weight on and weight off wheels); report the measured pressure, ‘H’ dimension, temperature, and boroscopic inspection findings to Airbus for further assessment; and restore the NLG in accordance with Airbus recommendations.
                If there are no findings: At the initial threshold inspection, do a servicing check (weight on wheels) of the NLG shock absorber. If the pressure is not within permissible tolerance, adjust the pressure and do the servicing check again with the weight off the wheels. If the pressure is not within permissible tolerance with the weight off the wheels, do a full service of the NLG shock absorber. The service bulletin states that it is not necessary to do these actions again at the repetitive intervals unless there is a finding during the boroscopic inspection. The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, mandated the service information and issued EASA Airworthiness Directive 2006-0174, dated June 21, 2006, to ensure the continued airworthiness of these airplanes in the European Union. FAA's Determination and Requirements of the Proposed AD These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. As described in FAA Order 8100.14A, “Interim Procedures for Working with the European Community on Airworthiness Certification and Continued Airworthiness,” dated August 12, 2005, EASA has kept the FAA informed of the situation described above. We have examined EASA's findings, evaluated all pertinent information, and determined that AD action is necessary for airplanes of this type design that are certificated for operation in the United States. This proposed AD would supersede AD 2005-24-06 and would retain the requirements of the existing AD, except for the boroscope inspection required within 90 days specified in paragraph (i)(2), and the repair requirements of paragraph (j) of AD 2005-24-06. This proposed AD would also require accomplishing the actions specified in the service information described previously, except as discussed under “Differences among the Proposed AD, the EASA Airworthiness Directive, and the Service Bulletin.” Differences Among the Proposed AD, the EASA Airworthiness Directive, and the Service Bulletin The service bulletin specifies to contact the manufacturer for further assessment of the reported measured pressure, ‘H’ dimension, temperature, and boroscope inspection findings of the NLG shock absorber, but this proposed AD does not require such reporting and assessment. The service bulletin also specifies restoring the NLG in accordance with Airbus recommendations, but this proposed AD would require restoring the NLG in accordance with a method approved by the FAA or the EASA (or its delegated agent). Changes to Existing AD We have changed the airplane model designations in the applicability and in paragraph (f), “Records Review,” of this proposed AD to be consistent with the parallel EASA airworthiness directive. We have clarified paragraph (f) of this proposed AD to refer to BSCU standard L4.1 and L4.5, and added that Airbus Service Bulletin A320-32-1310, dated February 8, 2006, is one approved method for doing the records review. Costs of Compliance This proposed AD would affect about 720 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD. The average labor rate is $80 per work hour. Estimated Costs
Action
Work hours
Parts
Cost per airplane
Fleet costRecords review (required by AD 2005-24-06)
1
None
$80
$57,600.AFM revision (required by AD 2005-24-06)
1
None
$80
$57,600.Special detailed inspection in accordance with new service information (new proposed action)
1
None
$80, 
                             per inspection cycle
$57,600, per inspection cycle.
 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 
                    ( print page 16751)
                    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. § 39.13
  2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-14386 (70 FR 70715, November 23, 2005) and adding the following new airworthiness directive (AD): **Airbus:**
                                 Docket No. FAA-2007-27776; Directorate Identifier 2006-NM-170-AD. Comments Due Date (a) The FAA must receive comments on this AD action by May 7, 2007. Affected ADs (b) This AD supersedes AD 2005-24-06. Applicability (c) This AD applies to all Airbus Model A318, A319, A320, and A321 airplanes. Unsafe Condition (d) This AD results from a report of an incident where an airplane landed with the nose landing gear (NLG) turned 90 degrees from centerline, and from additional reports of NLG upper support anti-rotation lugs rupturing in service. We are issuing this AD to prevent landings with the NLG turned 90 degrees from centerline, which could result in 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. Restatement of Certain Requirements of AD 2005-24-06 Records Review (f) Within 5 days after November 30, 2005 (the effective date of AD 2005-24-06), perform a records review to determine whether the airplane is equipped with or has ever been equipped with an enhanced manufacturing and maintainability (EMM) braking and steering control unit (BSCU) part number (P/N) E21327001 (standard L4.1, installed by Airbus Modification 26965, or Airbus Service Bulletin A320-32-1912) or P/N E21327003 (standard L4.5, installed by Airbus Modification 33376, or Airbus Service Bulletin A320-32-1261). Airbus Service Bulletin A320-32-1310, dated February 8, 2006, is one approved method for doing the records review. (g) For airplanes on which a records review required by paragraph (f) of this AD conclusively determines that the airplane is not and never has been equipped with a BSCU P/N E21327001 or P/N E21327003, no further action is required by this AD. Airplane Flight Manual (AFM) Revision (h) For airplanes that are not specified in paragraph (g) of this AD and on which Airbus Modification 31152 has not been incorporated in production (i.e., applicable only to aircraft with steering powered by the green hydraulic system): Within 10 days after November 30, 2005, revise the Limitation Section of the Airbus A318/319/320/321 Aircraft Flight Manual (AFM) to include the following information. This may be done by inserting a copy of this AD into the AFM: “The ECAM message, in case of a nose wheel steering failure, will be worded as follows: —“WHEEL N/W STRG FAULT” for aircraft with the FWC E3 and subsequent standards —“WHEEL N.W STEER FAULT” for aircraft with the FWC E2 Standard. If the L/G SHOCK ABSORBER FAULT ECAM caution is triggered at any time in flight, and the WHEEL N/W STRG FAULT ECAM caution is triggered after the landing gear extension:
                            When all landing gear doors are indicated closed on ECAM WHEEL page, reset the BSCU: —A/SKID&N/W STRG—OFF THEN ON If the WHEEL N/W STRG FAULT ECAM caution is no longer displayed, this indicates a successful nose wheel re-centering and steering recovery.
                            Rearm the AUTO BRAKE, if necessary.
                            If the WHEEL N/W STRG FAULT ECAM caution remains displayed, this indicates that the nose wheel steering remains lost, and that the nose wheels are not centered. —During landing, delay nose wheel touchdown for as long as possible. —Refer to the ECAM STATUS. If the WHEEL N/W STRG FAULT ECAM caution appears, without the L/G SHOCK ABSORBER FAULT ECAM caution: —No specific crew action is requested by the WHEEL N/W STRG FAULT ECAM caution procedure. —Refer to the ECAM STATUS.” Note 1: When a statement identical to that in paragraph (h) of this AD has been included in the general revisions of the AFM, the general revisions may be inserted into the AFM, and the copy of this AD may be removed from the AFM. New Requirements of This AD Inspection Thresholds (i) For airplanes that are not specified in paragraph (g) of this AD, at the earlier of the times specified in paragraphs (i)(1) and (i)(2) of this AD: Do a special detailed inspection (boroscopic) for broken or cracked NLG upper support lugs and missing cylinder lugs, and do all applicable related investigative/corrective actions before further flight. Do all actions in accordance with Airbus Technical Note 957.1901/05, dated October 18, 2005, or the Accomplishment Instructions of Airbus Service Bulletin A320-32-1310, dated February 8, 2006. After the effective date of this AD, only Airbus Service Bulletin A320-32-1301, dated February 8, 2006, may be used. Where the service bulletin specifies that restoring the NLG is necessary in accordance with Airbus recommendations, this AD requires restoring the NLG in accordance with a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the European Aviation Safety Agency (EASA) (or its delegated agent). Repeat the inspection thereafter at the applicable interval specified in paragraph (j) or (k) of this AD. (1) Within 100 flight cycles following an electronic centralized aircraft monitoring (ECAM) caution “L/G SHOCK ABSORBER FAULT” associated with at least one of the following centralized fault display system (CFDS) messages specified in paragraph (i)(1)(i), (i)(1)(ii), or (i)(1)(iii) of this AD. (i) “N L/G EXT PROX SNSR 24GA TGT POS.” (ii) “N L/G EXT PROX SNSR 25GA TGT POS.” (iii) “N L/G SHOCK ABSORBER FAULT 2526GM.” (2) At the later of the times specified in paragraphs (i)(2)(i) and (i)(2)(ii) of this AD. (i) Within 20 months, 6,000 flight hours, or 4,500 flight cycles since the date of issuance of the original French standard airworthiness certificate, or French export certificate of airworthiness, whichever occurs first. (ii) Within 6 months, 1,800 flight hours, or 1,350 flight cycles after the effective date of this AD, whichever occurs first. Repetitive Inspection Intervals (j) For airplanes not specified in paragraph (g) of this AD that are equipped with EMM BSCU standard L4.1 or L4.5: Repeat the inspection specified in paragraph (i) of this AD thereafter at intervals not to exceed the earliest of 6 months; 1,800 flight hours; 1,350 
                                ( print page 16752)
                                flight cycles; or 100 flight cycles following certain ECAM cautions and CFDS messages, as specified in paragraph (i)(1) of this AD. (k) For airplanes not specified in paragraph (g) of this AD that are equipped with EMM BSCU standard L4.8 or a non-EMM BSCU: Repeat the inspection specified in paragraph (i) of this AD thereafter at intervals not to exceed the earliest of 20 months; 6,000 flight hours; 4,500 flight cycles; or 100 flight cycles following certain ECAM cautions and CFDS messages, as specified in paragraph (i)(1) of this AD. Note 2: For the purposes of this AD, a special detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. The examination is likely to make extensive use of specialized inspection techniques and/or equipment. Intricate cleaning and substantial access or disassembly procedure may be required.” Optional Terminating Action (l) For airplanes that are not specified in paragraph (g) of this AD: Installation of an NLG with new upper support anti-rotation lugs and new cylinder lugs, or installation of an NLG that was never driven by EMM BSCU standard L4.1 and L4.5; combined with installation of an EMM BSCU standard L4.8 or a non-EMM BSCU; constitutes terminating action for the requirements of this AD. Do the installations in accordance with a method approved by either the Manager, International Branch, ANM-116; or the EASA (or its delegated agent). Chapter 32 of the Airbus A318/A319/A320/A321 Aircraft Maintenance Manual (AMM) is one approved method for doing the installations. No Report Required (m) Although Airbus Service Bulletin A320-32-1310, dated February 8, 2006, specifies sending certain inspection results to Airbus, this AD does not include that requirement. Credit Paragraph (n) Inspections done before the effective date of this AD in accordance with Chapter 12, Subject 12-14-32 of the Airbus A318/A319/A320/A321 AMM, as revised by Airbus A318/A319/A320/A321 AMM Temporary Revision 12-001, dated November 13, 2005, are acceptable for compliance with the requirements of paragraph (i) of this AD. Alternative Methods of Compliance (AMOCs) (o)(1) The Manager, International Branch, ANM-116, 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. Related Information (p) EASA airworthiness directive 2006-0174, dated June 21, 2006, also addresses the subject of this AD.
 Issued in Renton, Washington, on March 26, 2007. Ali Bahrami, Manager,  Transport Airplane Directorate, Aircraft Certification Service.


[FR Doc. E7-6343 Filed 4-4-07; 8:45 am] BILLING CODE 4910-13-P