### 47534 Federal Register / Vol. 78, No. 151 / Tuesday, August 6, 2013 / Rules and Regulations

TABLE 

### 1 TO 

### PARAGRAPH 

### (e)—Continued

UT inspect grip, P/N Within 30 days, for a grip with the following or more hours TIS: Thereafter, at intervals not to exceed the following number of hours TIS or the engine start/stop cycles, whichever occurs first:

Hours TIS Engine start/stop cycles

204–011–121–005 or –113, if the grip was EVER installed on a Model 205B or Model

UH–1N helicopter ......................................................................................................... 4,000 400 1,600 204–011–121–117, if the grip was EVER installed on a Model 205B helicopter ........... 500 150 600

(3) At intervals not to exceed 1,200 hours TIS or 24 months, whichever occurs first:

(i) Remove each main rotor blade, and (ii) Inspect each grip buffer pad on the inner surfaces of each grip tang for delamination as depicted in Figure 5–7, Inspection of Main Rotor Hub Grip (1200 Hours), Revision 9, dated August 8, 2008, of Chapter 5, Inspections and Component Overhaul Schedule, Revision 11, dated April 30, 2010, of Bell Helicopter Textron, Inc., BHT–212–MM–1, Revision 13, dated September 16, 2010. If there is any delamination, remove the buffer pad and inspect the grip surface for corrosion or other damage.

(4) Within 2,400 hours TIS or at the next overhaul of the main rotor hub, whichever occurs first, and then at intervals not to exceed 2,400 hours TIS:

(i) Remove each main rotor blade. (ii) Remove each grip buffer pad (if installed) from the inner surfaces of each grip tang.

(iii) Visually inspect the grip surfaces for corrosion or other damage.

(iv) Fluorescent-penetrant inspect (FPI) the grip for a crack, paying particular attention to the upper and lower grip tangs. When inspecting a grip, P/N 204–011–121–005, 204–011–121–009, or 204–011–121–113, or ASI–4011–121–9, pay particular attention to the leading and trailing edges of the grip barrel.

(5) Before further flight: (i) Replace any cracked grip with an airworthy grip.

(ii) Replace any grip with any corrosion or other damage with an airworthy grip, or repair the grip if the corrosion or other damage is within the maximum repair limitations.

(iii) Remove any grip, P/N 204–011–121– 009 or ASI–4011–121–9, that has been in service for 15,000 or more hours TIS.

(iv) Remove any grip, P/N 204–011–121– 121, that has been in service for 25,000 or more hours TIS.

(6) Revise the Airworthiness Limitations section of the applicable maintenance manual or the Instructions for Continued Airworthiness (ICA) by establishing a new retirement life of 15,000 hours TIS for grip, P/N 204–011–121–009 or ASI–4011–121–9, and 25,000 hours TIS for grip, P/N 204–011– 121–121, by marking pen and ink changes or inserting a copy of this AD into the maintenance manual or ICA.

(7) Record a 15,000 hour TIS life limit for each grip, P/N 204–011–121–009 or ASI– 4011–121–9, and a 25,000 hour life limit for each grip, P/N 204–011–121–121, on the applicable component history card or equivalent record. (f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Rotorcraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Michael Kohner, Aviation Safety Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222–5170; email 7-avs-asw-170@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.
(g) Additional Information

BHTI Alert Service Bulletin (ASB) 212–94– 92, Revision A, dated March 13, 1995; BHTI Operations Safety Notice (OSN) 204–85–6, OSN 205–85–9, and OSN 212–85–13, all dated November 14, 1985 and co-published as one document; BHTI ASB 205B–02–39, Revision B, dated November 22, 2002; and BHTI ASB 212–02–116, Revision A, dated October 30, 2002, which are not incorporated by reference, contain additional information about the subject of this AD.
(h) Subject

Joint Aircraft Service Component (JASC) Code: 6220, Main rotor head.
(i) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Bell Helicopter Textron, Inc. Nondestructive Inspection Procedure, Log No. 00–340, Revision E, dated April 9, 2002.

(ii) Figure 5–7, Inspection of Main Rotor Hub Grip (1200 Hours), Revision 9, dated August 8, 2008, of Chapter 5, Inspections and Component Overhaul Schedule, Revision 11, dated April 30, 2010, of Bell Helicopter Textron, Inc., BHT–212–MM–1, Revision 13, dated September 16, 2010.

(3) For BHTI service information identified in this AD, contact Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, TX 76101; telephone (817) 280–3391; fax (817) 280– 6466; or at http://www.bellcustomer.com/ files/.

(4) You may review a copy of this service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

(5) You may also review a copy of this service information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741–6030, or go
to: http://www.archives.gov/federal-register/ cfr/ibr-locations.html.

Issued in Fort Worth, Texas, on June 18,
2013. Kim Smith, Directorate Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2013–18570 Filed 8–5–13; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2013–0447; Directorate Identifier 2013–NE–17–AD; Amendment 39–**  **17536; AD 2013–15–20]**

**RIN 2120–AA64**

**Airworthiness Directives; General Electric Company Turbofan Engines** 

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule; request for
comments.

**SUMMARY :**  We are superseding emergency airworthiness directive (AD) 2013–14–51 for General Electric Company (GE) GE90–110B1 and GE90– 115B turbofan engines with affected transfer gearbox assembly (TGB) radial gearshafts installed. AD 2013–14–51 was sent previously to all known U.S. owners and operators of GE90–110B1 and GE90–115B turbofan engines. AD 2013–14–51 prohibited operation of an airplane if more than one installed engine has an affected TGB radial


### 47535 Federal Register / Vol. 78, No. 151 / Tuesday, August 6, 2013 / Rules and Regulations

gearshaft. This AD contains the same prohibition as AD 2013–14–51 and also prohibits operation of any airplane 60 days after the effective date of this new AD if any installed engine has an affected TGB radial gearshaft. This new AD also revises the applicability by adding GE90–76B, GE90–77B, GE90– 85B, GE90–90B, GE90–94B, and GE90– 113B turbofan engine models and adds a mandatory terminating action. This new AD was prompted by reports of three failures of TGB radial gearshafts which resulted in in-flight shutdowns (IFSDs). We are issuing this new AD to prevent failure of the TGB radial gearshaft, which could result in IFSD of one or more engines, loss of thrust control, and damage to the airplane.

**DATES :**  This AD is effective August 21,
2013.

We must receive any comments on this AD by September 20, 2013.

**ADDRESSES :**  You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202–493–2251.

• Mail: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590.

• Hand Delivery: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact General Electric Company, One Neumann Way, Room 285, Cincinnati, OH; phone: 513–552– 3272; email: geae.aoc@ge.com. You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125. Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: 800–647– 5527) is in the **ADDRESSES** section. Comments will be available in the AD docket shortly after receipt.

**FOR FURTHER INFORMATION CONTACT :**  Carlos Fernandes, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7189; fax: 781–238– 7199; email: carlos.fernandes@faa.gov.

**SUPPLEMENTARY INFORMATION :** 

Discussion

On May 16, 2013, we issued emergency AD 2013–10–52 (issued on June 16, 2013, as a Final Rule, Request for Comments (78 FR 38195, June 26, 2013)), which was immediately effective to owners and operators of GE GE90– 110B1 and GE90–115B turbofan engines. That AD resulted from reports of two failures of TGB radial gearshafts that resulted in IFSDs. That AD prohibited operation of an airplane with affected TGBs installed on both engines.

On July 12, 2013, we issued emergency AD 2013–14–51, superseding AD 2013–10–52 (78 FR 38195, June 26, 2013). AD 2013–14–51 also prohibits operation of an airplane with affected TGB radial gearshafts installed on both engines. AD 2013–14–51 resulted from a report of an additional failure of a TGB radial gearshaft, outside the population identified in AD 2013–10–52. We issued ADs 2013–10–52 and 2013–14–51 to prevent failure and separation of the TGB radial gearshaft, which could result in IFSD of one or more engines, loss of thrust control, and damage to the airplane.

Actions Since AD 2013–14–51 Was Issued

Since we issued emergency AD 2013– 14–51, dated July 12, 2013, we determined that airplanes with an installed engine with an affected TGB radial gearshaft should not be allowed to operate more than 60 days after the effective date of this new AD. We also revised the Applicability of this new AD since we determined that the affected TGB radial gearshafts are installed on additional GE90 engine models besides the GE90–110B1 and GE90–115B. We also determined the need to add a mandatory terminating action.

Relevant Service Information

We reviewed GE GE90–100 Series Alert Service Bulletin (ASB) No. GE90– 100 S/B 72–A0568, dated July 10, 2013; GE GE90–100 Series Service Bulletin (SB) No. GE90–100 S/B 72–0569, Revision 0, dated July 19, 2013; and GE GE90 SB No. GE90 S/B 72–1091, Revision 0, dated June 11, 2013, which provide additional information regarding the affected TGB radial gearshafts. We also reviewed GE GE90– 100 Series SB No. GE90–100 S/B 72– 0563, Revision 0, dated June 21, 2013, and Revision 1, dated July 10, 2013; and GE GE90 SB No. GE90 S/B 72–1066, Revision 0, dated June 21, 2013; which provide information regarding the mandatory terminating action.

FAA’s Determination

We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.
AD Requirements

This AD prohibits operation of an airplane with affected TGB radial gearshafts installed on both engines after the effective date of this AD. This AD also prohibits operation of an airplane with affected TGB radial gearshafts installed on any engine 60 days after the effective date of this AD. This AD also adds a mandatory terminating action, namely, to install a TGB radial gearshaft that is eligible for installation.
FAA’s Justification and Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because of the before further flight compliance time. Therefore, we find that notice and opportunity for prior public comment are impracticable and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the **ADDRESSES** section. Include the docket number FAA–2013–0447 and directorate identifier 2013–NE–17–AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those
comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each


### 47536 Federal Register / Vol. 78, No. 151 / Tuesday, August 6, 2013 / Rules and Regulations

substantive verbal contact we receive about this AD. Costs of Compliance

We estimate that this AD will affect about 16 GE90 engines installed on airplanes of U.S. registry. We also estimate that it will take about eight hours per engine to replace the TGB radial gearshaft. The average labor rate is $85 per hour. The cost of this part is about $16,700. Based on these figures, we estimate the total cost of this AD to U.S. operators to be $278,080. 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

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 DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction, and

(4) 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. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: **PART 39—AIRWORTHINESS DIRECTIVES** 

■ 1. The authority citation for part 39 continues to read as follows:

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

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by:

■ a. Removing AD 2013–10–52 (78 FR 38195, June 26, 2013); and

■ b. Adding the following new AD: 2013–15–20: Amendment 39–17536; Docket No. FAA–2013–0447; Directorate Identifier 2013–NE–17–AD.
(a) Effective Date

This AD is effective August 21, 2013.
(b) Affected ADs

This AD supersedes Emergency AD 2013–14–51, Directorate ID 2013–NE– 17–AD, dated July 12, 2013. This AD also removes AD 2013–10–52 (78 FR 38195, June 26, 2013) from the Code of Federal Regulations. (c) Applicability

General Electric Company (GE) GE90– 76B, GE90–77B, GE90–85B, GE90–90B, GE90–94B, GE90–110B1, GE90–113B and GE90–115B turbofan engines with a transfer gearbox assembly (TGB) radial gearshaft, part number (P/N) 1995M24P02, serial number (S/N) listed in Figure 1 to paragraph (c) of this AD, installed.



### F IGURE 

### 1 TO 

### PARAGRAPH 

### (c)—TGB RADIAL 

### G EARSHAFT 

### P/N 1995M24P02 S/N’ S

FIA0KCYG FIA0JETA FIA0H0VJ FIA0HL0C FIA0K63F FIA0J7V2 FIA0K62R FIA0HLY9 FIA0K3A3 FIA0KCYM FIA0K63C FIA0HL0E FIA0JVRE FIA0JJ6E FIA0K89H FIA0HL0F FIA0H0VM FIA0JNJH FIA0KCYK FIA0HL0G FIA0K3A4 FIA0K62W FIA0K3A5 FIA0HLY7 FIA0K62T FIA0K89P FIA0HWKA FIA0HJTE FIA0JJ53 FIA0JJ57 FIA0KCYR FIA0HJTJ FIA0K89W FIA0JJ56 FIA0HWKE FIA0HJTG FIA0KCW8 FIA0KH9Y FIA0J7WH FIA0HJTC FIA0K3A6 FIA0KCYP FIA0JER9 FIA0HJTF FIA0HY8C FIA0JJ55 FIA0JNJJ FIA0HJTH FIA0K3AP FIA0KH9G FIA0JVRR FIA0HJTA FIA0J7WG FIA0KH9H FIA0JNJM FIA0HJR9 FIA0JVRL FIA0KH9K FIA0KH9R FIA0HWJ7 FIA0J7V1 FIA0KH9C FIA0KH9P FIA0HY76 FIA0JVRM FIA0K63H FIA0K89C FIA0HY8F FIA0K3AV FIA0K63M FIA0JVRH FIA0H0VK FIA0J7V8 FIA0K62Y FIA0K89L FIA0J7VR FIA0J7WE FIA0JVP9 FIA0JER6 FIA0JJ58 FIA0K3A2 FIA0K63E FIA0JETH FIA0JJ6C FIA0K3A1 FIA0K3AY FIA0H0VC FIA0JNJF FIA0K3AN FIA0JVRT FIA0K3AL FIA0JNJK FIA0JVRP FIA0HY8E FIA0J7VV FIA0JVRC FIA0JJ6F FIA0HY8N FIA0J7VP FIA0J7V4 FIA0JJ6J FIA0J7V0 FIA0J7V9 FIA0JETF FIA0JVRV FIA0J7V3 FIA0HWJ8 FIA0HEG4 FIA0H0VL FIA0J7V5 FIA0H0VA FIA0HWJ9 FIA0K89T FIA0HY8H FIA0KCYL FIA0HWJ5 FIA0K89Y FIA0HEG2 FIA0HY79 FIA0HWJ6


### 47537 Federal Register / Vol. 78, No. 151 / Tuesday, August 6, 2013 / Rules and Regulations

F IGURE 

### 1 TO 

### PARAGRAPH 

### (c)—TGB RADIAL 

### G EARSHAFT 

### P/N 1995M24P02 S/N’ S

### —Continued

FIA0JETL FIA0K62V FIA0KH9J FIA0J7VW FIA0JER8 FIA0HEGY FIA0HY8G FIA0J7VY FIA0J7WC FIA0HWKC FIA0HY8M FIA0J7VT FIA0JETE FIA0K3A0 FIA0HY8A FIA0J7WF FIA0K3AT FIA0JVRJ FIA0H0VG FIA0J7V6 FIA0JJ59 FIA0K8AA FIA0K3AR FIA0K89G FIA0K3AW FIA0KCYT FIA0JETC FIA0K89K FIA0JVRN FIA0KH9T FIA0KH9W FIA0K89R FIA0JNH8 FIA0HEG1 FIA0JNJC FIA0KCYJ FIA0JETN FIA0HEG3 FIA0K63L FIA0JJ6G FIA0HY78 FIA0J7WJ FIA0KCYN FIA0JJ6A FIA0HY75 FIA0JER7 FIA0JVRG FIA0HY8K FIA0HEG0 FIA0JVRF FIA0HY8L FIA0HLY6 FIA0KH9E FIA0K63K FIA0HY8J FIA0HLY0 FIA0KH9F FIA0J7WK FIA0H0VH FIA0HLY1 FIA0H0T9 FIA0JER5 FIA0H0VF FIA0HLY4 FIA0HLY3 FIA0JETM

(d) Unsafe Condition

This AD was prompted by reports of three failures of TGB radial gearshafts which resulted in in-flight shutdowns (IFSDs). We are issuing this AD to prevent failure of the TGB radial gearshaft, which could result in IFSD of one or more engines, loss of thrust control, and damage to the airplane. (e) Compliance

(1) Comply with this AD within the compliance times specified, unless already done.

(2) Before further flight after the effective date of this AD, do not operate the airplane if more than one installed engine has a TGB radial gearshaft P/N and S/N listed in Figure 1 to paragraph (c) of this AD. (f) Mandatory Terminating Action

No later than 60 days after the effective date of this AD, as terminating action to the requirements of paragraph (e) of this AD, replace all TGB radial gearshafts identified in Figure 1 to paragraph (c) of this AD that are installed on an airplane with TGB radial gearshafts that are eligible for installation. (g) Prohibition on Operation

Sixty days after the effective date of this AD, do not operate any airplane that has an engine installed that has a TGB radial gearshaft P/N and S/N listed in Figure 1 to paragraph (c) of this AD.
(h) Definition

For the purposes of this AD, a TGB radial gearshaft eligible for installation is:(1) A TGB radial gearshaft P/N and S/ N, not listed in this AD or

(2) A TGB radial gearshaft with an S/ N listed in paragraph (c) of this AD with part number 1995M24P04, 2205M61P01 or 2205M61P02. (i) Alternative Methods of Compliance (AMOCs)

The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures in 14 CFR 39.19 to make your request.
(j) Related Information

(1) For more information about this AD, contact Carlos Fernandes, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7189; fax: 781– 238–7199; email: carlos.fernandes@faa.gov.

(2) GE GE90–100 Series Alert Service Bulletin No. GE90–100 S/B 72–A0568, Revision 0, dated July 10, 2013; GE GE90–100 Series Service Bulletin (SB) No. GE90–100 S/B 72–0569, Revision 0, dated July 19, 2013; GE GE90–100 Series SB No. GE90–100 S/B 72–0563, Revision 0, dated June 21, 2013, and Revision 1, dated July 10, 2013; GE GE90 SB No. GE90 S/B 72–1066, Revision 0, dated June 21, 2013; and GE GE90 SB No. GE90 S/B 72–1091, Revision 0, dated June 11, 2013, can be obtained from GE using the contact information in paragraph (j)(3) of this AD.

(3) For service information identified in this AD, contact General Electric Company, One Neumann Way, Room 285, Cincinnati, OH; phone: 513–552– 3272; email: geae.aoc@ge.com.

(4) You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125.
(k) Material Incorporated by Reference

None. Issued in Burlington, Massachusetts, on July 25, 2013. Frank P. Paskiewicz, Acting Director, Aircraft Certification Service.
[FR Doc. 2013–18840 Filed 8–5–13; 8:45 am]

**BILLING CODE 4910–13–P**

**DEPARTMENT OF TRANSPORTATION**

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2012–1033; Directorate Identifier 2010–NM–266–AD; Amendment**  **39–17504; AD 2013–13–16]**

**RIN 2120–AA64**

**Airworthiness Directives; Airbus Airplanes** 

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

**ACTION :**  Final rule.

**SUMMARY :**  We are superseding airworthiness directive (AD) 2005–07– 04 for all Airbus Model A330–200 and –300 series airplanes, and Model A340– 200 and –300 series airplanes. AD 2005– 07–04 required repetitive inspections to detect discrepancies of the transfer tubes and the collar of the ball nut of the trimmable horizontal stabilizer actuator (THSA), and corrective action if necessary; repetitive inspections for discrepancies of the ball screw assembly, and corrective action if necessary; repetitive greasing of the THSA ball nut, and replacement of the THSA if necessary; and modification or replacement (as applicable) of the ball nut assembly, which ends certain repetitive inspections. This new AD removes certain inspections, revises certain actions, and adds airplanes to the applicability. This AD was prompted by several reports of