[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
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 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  

[[Page 41737]]


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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

[[Page 41738]]

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

[[Page 41739]]

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