Airworthiness Directives; Israel Aircraft Industries (IAI), Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 1124A Series Airplanes

[Federal Register Volume 63, Number 150 (Wednesday, August 5, 1998)] [Proposed Rules] [Pages 41737-41739] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-20835]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 63, No. 150 / Wednesday, August 5, 1998 / Proposed Rules

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-108-AD] RIN 2120-AA64

Airworthiness Directives; Israel Aircraft Industries (IAI), Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 1124A Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all IAI, Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 1124A series airplanes, that currently requires repetitive inspections of the trim actuator of the horizontal stabilizer to verify jackscrew integrity and to detect excessive wear of the tie rod, and replacement of the actuator or tie rod, if necessary. That AD also provides for optional terminating action for the repetitive inspections. This action would require accomplishment of the previously optional terminating action. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent failure of the trim actuator of the horizontal stabilizer due to failure of the jackscrews, which could result in reduced controllability of the airplane.

DATES: Comments must be received by September 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-108-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Galaxy Aerospace Corporation, One Galaxy Way, Fort Worth Alliance Airport, Fort Worth, Texas 76177. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-108-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-108-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On February 24, 1998, the FAA issued AD 98-05-09, amendment 39- 10370 (63 FR 11106, March 6, 1998), applicable to all Israel Aircraft Industries (IAI), Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 1124A series airplanes, to require repetitive inspections of the trim actuator of the horizontal stabilizer to verify jackscrew integrity and to detect excessive wear of the tie rod, and replacement of the actuator or tie rod, if necessary. That action was prompted by a report indicating that, during an inspection, an operator found one sheared actuator jackscrew of the horizontal stabilizer on an airplane, which caused the rod end to separate from the jackscrew. The requirements of that AD are intended to ensure that the trim actuator of the horizontal stabilizer operates properly; failure of the actuator to operate properly could result in reduced controllability of the airplane.

Actions Since Issuance of Previous Rule

When AD 98-05-09 was issued, it contained a provision for an optional replacement of the trim actuator of the horizontal stabilizer with a modified trim actuator with modified jackscrew assemblies, which, if accomplished, would constitute terminating action for the required repetitive inspections. Moreover, in AD 98-05-09, the FAA indicated that the inspections required by that AD are to be performed as interim action, and that it was considering further rulemaking to require replacement of the trim actuator of the horizontal stabilizer. This action proposes such a requirement, to be accomplished in accordance with Commodore Jet Service Bulletin SB 1121-27-025, dated December 22, 1997 (for Model 1121, 1121A, and 1121B series airplanes); Westwind Service Bulletin SB 1123-27-047, dated September 1, 1997 (for Model 1123 series airplanes); or Westwind Service Bulletin 1124-27-136, dated September 1, 1997 (for Model 1124 and 1124A series airplanes). These service bulletins were described previously in AD 98-05-09. The FAA's determination to require accomplishment of the terminating modification is based on the fact that the repetitive inspections currently required by AD 98-05-09 only detect

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failures of the jackscrew, rather than detecting reduced structural integrity of these parts. That is, the inspections cannot determine whether cracking exists that may result in future structural failure of the horizontal stabilizer jackscrews. In order to adequately detect such cracking, a non-destructive test (NDT) inspection method would be required. However, use of any NDT inspection method would necessitate removal and disassembly of the horizontal stabilizer in order to gain access to the jackscrews for such inspection, which would entail considerable work hours. Additionally, such inspections would be required to be accomplished on a repetitive basis. Therefore, the FAA has determined that long-term continued operational safety will be better assured by replacement of the trim actuator with a trim actuator having a modified jackscrew assembly to remove the source of the problem, rather than by repetitive inspections. The proposed replacement requirement is also in consonance with actions taken by the Civil Aviation Administration of Israel (CAAI), which is the airworthiness authority for Israel. (The CAAI issued Israeli airworthiness directive 27-97-09-02 on September 4, 1997, which requires replacement of the trim actuator with a modified trim actuator, in order to assure the airworthiness of these airplanes in Israel.)

FAA's Conclusions

These airplane models are manufactured in Israel 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. Pursuant to this bilateral airworthiness agreement, the CAAI has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAAI, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would supersede AD 98-05-09 to continue to require repetitive inspections of the trim actuator of the horizontal stabilizer to verify jackscrew integrity and to detect excessive wear of the tie rod, and replacement of the actuator or tie rod, if necessary. In addition, the proposed AD would require the eventual replacement of the trim actuator of the horizontal stabilizer with a modified trim actuator with modified jackscrew assemblies, which would terminate the repetitive inspection requirements. The FAA notes that Israeli airworthiness directive 27-97-09-02, dated September 4, 1997, includes a note that references the revised Instructions for Continued Airworthiness for inspection requirements, overhaul requirements, and service life limitations of the modified trim actuator and its modified jackscrew assemblies and other parts. The FAA is considering further rulemaking to mandate compliance with the new inspections and life limitations requirements.

Cost Impact

There are approximately 295 airplanes of U.S. registry that would be affected by this proposed AD. The inspections that are currently required by AD 98-05-09 take approximately 4 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $70,800, or $240 per airplane, per inspection cycle. The new replacement that is proposed by this AD action would take approximately 4 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $49,500 per airplane. Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $14,673,300, or $49,740 per airplane. The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein would not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-10370 (63 FR 11106, arch 6, 1998), and by adding a new airworthiness directive (AD), to read as follows:

Israel Aircraft Industries (IAI), Ltd.: Docket 98-NM-108-AD. Supersedes AD 98-05-09, Amendment 39-10370.

Applicability: All Model 1121, 1121A, 1121B, 1123, 1124, and 1124A series airplanes; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously. To prevent failure of the trim actuator of the horizontal stabilizer due to failure of the

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jackscrews, which could result in reduced controllability of the airplane, accomplish the following:

Restatement of Requirements of Paragraphs (a) and (b) of AD 98-05-09

(a) Perform an inspection of the trim actuator of the horizontal stabilizer to verify jackscrew integrity and to detect excessive wear of the tie rod, in accordance with Commodore Jet Service Bulletin SB 1121-27-023, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1121, 1121A, and 1121B series airplanes); Westwind Service Bulletin SB 1123-27-046, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1123 series airplanes); or Westwind Service Bulletin SB 1124-27-133, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1124 and 1124A series airplanes); as applicable; at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. (1) For airplanes that have accumulated 6,000 or more total flight cycles, or on which the horizontal trim actuator has accumulated 2,000 or more flight cycles, as of April 10, 1998 (the effective date of AD 98-05-09, amendment 39-10370): Inspect within 50 flight hours after April 10, 1998. Repeat the inspection thereafter at intervals not to exceed 300 flight hours (for Model 1121, 1121A, 1121B, and 1123 series airplanes); or 400 flight hours (for Model 1124 and 1124A series airplanes); as applicable. (2) For airplanes that have accumulated less than 6,000 total flight cycles, and on which the horizontal trim actuator has accumulated less than 2,000 total flight cycles, as of April 10, 1998: Inspect at the time specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as applicable. (i) For Model 1121, 1121A, 1121B, and 1123 series airplanes: Inspect within 300 flight hours after April 10, 1998. Repeat the inspection thereafter at intervals not to exceed 300 flight hours. (ii) For Model 1124 and 1124A series airplanes: Inspect within 400 flight hours after April 10, 1998. Repeat the inspection thereafter at intervals not to exceed 400 flight hours. (b) If any discrepancy is found during any inspection required by paragraph (a) of this AD, prior to further flight, replace the actuator or tie rod, as applicable, in accordance with Commodore Jet Service Bulletin SB 1121-27-023, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1121, 1121A, and 1121B series airplanes); Westwind Service Bulletin SB 1123-27-046, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1123 series airplanes); or Westwind Service Bulletin 1124-27-133, dated August 14, 1996, or Revision 1, dated May 28, 1997 (for Model 1124 and 1124A series airplanes); as applicable.

New Requirements of this AD

(c) Within 18 months after the effective date of this AD, replace the trim actuator of the horizontal stabilizer with a modified trim actuator with modified jackscrew assemblies (part number 21164-362 and -363 for Model 1121, 1121A, and 1121B series airplanes; part number 21164-360 and -361 for Model 1123 series airplanes; or part number 21164-360 and -361 for Model 1124 and 1124A series airplanes), in accordance with Commodore Jet Service Bulletin SB 1121-27-025, dated December 22, 1997 (for Model 1121, 1121A, and 1121B series airplanes); Westwind Service Bulletin SB 1123-27-047, dated September 1, 1997 (for Model 1123 series airplanes); or Westwind Service Bulletin SB 1124-27-136, dated September 1, 1997 (for Model 1124 and 1124A series airplanes); as applicable. Accomplishment of this replacement terminates the repetitive inspections required by this AD. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, International Branch, ANM-116.

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Note 3: The subject of this AD is addressed in Israeli airworthiness directive 27-97-09-02, dated September 4, 1997.

Issued in Renton, Washington, on July 29, 1998. D. L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-20835 Filed 8-4-98; 8:45 am] BILLING CODE 4910-13-U