AD 98-20-35

This amendment supersedes 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 amendment requires accomplishment of the previously optional terminating action. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this 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.

The incorporation by reference of certain publications was approved previously by the Director of the Federal Register as of April 10, 1998 (63 FR 11106, March 6, 1998).

Final rule.

98-20-35 Israel Aircraft Industries (IAI), Ltd.: Amendment 39-10802. 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 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 thehorizontal 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 AirplaneDirectorate. 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.

(f) The actions shall be done in accordance with the following Westwind and Commodore Jet service bulletins, as applicable, which contain the specified effective pages:

Service Bulletin
Referenced and Date
Page Number
Shown on Page
Revision Level
Shown on Page
Date
Shown on Page
Westwind,
SB 1124-27-133,
August 14, 1996.

1-6

OriginalAugust 14, 1996
Westwind,
SB 1124-27-133,
Revision 1,
May 28, 1997

1-4

5, 6

1

Original

May 28, 1997

August 14, 1996
Westwind,
SB 1123-27-046,
August 14, 1996.

1-6

Original

August 14, 1996
Westwind,
SB 1123-27-046,
Revision 1
May 28, 1997.

1-4

5, 6

1

Original

May 28, 1997

August 14, 1996
Westwind,
SB 1124-27-136,
September 1, 1997

1-3

Original

September 1, 1997
Westwind,
SB 1123-27-047,
September 1, 1997

1-3

Original

September 1, 1997
Commodore Jet,
B 1121-27-025,.
December 22, 1997

1-3

Original

December 22, 1997
Commodore Jet,
SB 1121-27-023,
August 14, 1996

1-6

Original

August 14, 1996
Commodore Jet,
SB 1121-27-023,
Revision 1, May 28, 1997

1-4

5, 6

1

Original

May 28, 1997

August 14, 1996

The incorporation by reference was approved previously by the Director of the Federal Register as of April 10, 1998 (63 FR 11106, March 6, 1998). Copiesmay be obtained from Galaxy Aerospace Corporation, One Galaxy Way, Fort Worth Alliance Airport, Fort Worth, Texas 76177. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.

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

(g) This amendment becomes effective on November 3, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 98-05-09, amendment 39-10370 (63 FR 11106, March 6, 1998), which is applicable to all IAI, Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 1124A series airplanes, was published in the Federal Register on August 5, 1998 (63 FR 41737). The action proposed 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. The action also proposed to require accomplishment of a previously optional terminating action.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
There are approximately 295 airplanes of U.S. registry that will be affected by this 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 required by this AD action will take approximately 4 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $49,500 per airplane. Based on these figures, the cost impact of the replacement required 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 anyof the 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 adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (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); 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES
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, March 6, 1998), and by adding a new airworthiness directive (AD), amendment 39-10802, to read as follows: