AD Amdt-39-10370

[Federal Register Volume 63, Number 44 (Friday, March 6, 1998)]
[Rules and Regulations]
[Pages 11106-11108]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-5348]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-166-AD; Amendment 39-10370; AD 98-05-09]
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: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all IAI, Ltd., Model 1121, 1121A, 1121B, 1123, 1124, and 
1124A series airplanes, that 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. This amendment is prompted by 
issuance of mandatory continued airworthiness information by a foreign 
civil airworthiness authority. The actions specified by this 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.

DATES: Effective April 10, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 10, 1998.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all IAI, Ltd., Model 1121, 1121A, 
1121B, 1123, 1124, and 1124A series airplanes was published in the 
Federal Register on August 11, 1997 (62 FR 42952). That action proposed 
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.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Requests to Mandate Modifications

    One commenter requests that the FAA not issue this AD, but instead 
issue an AD to require replacement of the trim actuator of the 
horizontal stabilizer. This commenter notes that a modification to the 
jackscrew threads has been identified, which will reduce stress 
concentration at the thread root and would eliminate the need to 
conduct the inspections of the jackscrews. The commenter further notes 
that, since the issuance of the proposed rule, Galaxy Aerospace 
Corporation has issued Westwind Service Bulletins SB 1123-27-047 (for 
Model 1123 series airplanes) and SB 1124-27-136 (for Model 1124 and 
1124A series airplanes), both dated September 1, 1997. The commenter 
also notes that Galaxy Aerospace Corporation is scheduled to issue 
Commodore Jet Service Bulletin SB 1121-27-025 (for Model 1121, 1121A, 
and 1121B series airplanes) in December 1997. These three service 
bulletins describe procedures for replacement of the trim actuators of 
the horizontal stabilizer with modified trim actuators containing 
jackscrews with modified threads. The commenter considers that 
accomplishment of these service bulletins provides a more effective 
means to resolve the safety of flight issues.
    The FAA concurs partially with the commenter's request. Since the 
issuance of the proposed rule, Galaxy Aerospace Corporation has issued 
Service Bulletin SB 1121-27-025, dated December 22, 1997. The FAA 
agrees that replacement of the trim actuator of the horizontal 
stabilizer with a modified trim actuator in accordance with the 
procedures described in the three service bulletins referenced 
previously provides a more effective means to prevent failure of the 
trim actuator jackscrews and would eliminate the need for the 
repetitive inspections required by this AD. Therefore, the final rule 
has been revised to include the replacement of the trim actuator as an 
optional terminating action.
    However, the FAA does not agree that this AD, which would require 
inspections, should be withdrawn. Rather, the FAA considers that, 
consistent with the actions taken by the Civil Aviation Administration 
of Israel (CAAI), and due to the urgency of the problem, the 
inspections must be performed as an interim action to ensure safe 
operation. Although the replacement of the trim actuator is provided as 
an optional terminating action in this final rule, the FAA is 
considering further rulemaking to require replacement of the trim 
actuator on all affected airplanes. The FAA notes that Israeli 
airworthiness directive 27-97-09-02 was issued on September 4, 1997. 
That airworthiness directive requires replacement of the trim actuator 
with a modified trim actuator in accordance with the service bulletins 
defined above, and specifies that the replacement of the trim actuator 
is terminating action for the repetitive inspections required by 
Israeli airworthiness directive 96-92 dated September 1, 1996, which is 
the Israeli airworthiness directive addressed by this AD.

Request To Not Mandate Modifications

    One commenter supports the requirement of the proposed AD to 
perform repetitive inspections of the jack screws and tie rods of the 
trim actuator of the horizontal stabilizer. However, this commenter 
(and several others) object to any plans to mandate replacement of the 
trim actuators. The commenter notes that it is only aware of one 
cracked eye bolt that was found during inspections of the trim 
actuators. The commenter also notes that some of the modified trim 
actuators were obtained from non-operable aircraft in salvage yards, 
and that it believes that the trim actuator could be rebuilt to meet 
the specifications for much less cost than the price quoted in the 
service bulletins. The commenter considers that the replacement of the 
trim actuators is driven by money issues and not safety issues. Other 
commenters consider the replacement too costly. Another commenter notes 
that both broken jack screws were found on airplanes operated by the 
same flight department, and that this may not be a fleet-wide problem.
    The FAA points out that this AD does not mandate replacement of the 
trim actuators of the horizontal stabilizer, but rather now provides 
for optional terminating action to replace the trim actuators. However, 
as stated above, the FAA is considering further rulemaking

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to require replacement of the trim actuators on all affected airplanes. 
The FAA will consider the remarks submitted by these commenters, and 
will determine whether other options are available to address the 
identified unsafe conditions. In addition, under the provisions of 
paragraph (e) of this final rule, the FAA may approve requests for 
approval of an alternative method of compliance for the requirements of 
this AD, if data are submitted to substantiate that accomplishment of 
such actions would provide an acceptable level of safety.

Request To Include Later Revisions of the Service Information

    One commenter requests that the AD be revised to include an option 
to inspect the jackscrews of the trim actuator in accordance with 
Revision 1 of the service bulletins referenced in the proposed AD. The 
commenter notes that the service bulletins referenced in the proposed 
AD have been revised to permit use of alternative sealants during 
reassembly following inspection.
    The FAA concurs with the commenter's request, and has revised this 
final rule to include an option to comply with Revision 1 of the 
service bulletins.

Request To Change Name and Address of Service Information Source

    One commenter requests that the AD be revised to change the name 
and address where service information can be obtained. The commenter 
notes that Astra Jet Corporation no longer provides support for these 
aircraft, and that all references to Astra Jet Corporation should be 
changed to ``Galaxy Aerospace Corporation.'' The commenter further 
notes that, effective October 13, 1997, the new address for customer 
service and product support for IAI products is: Galaxy Aerospace 
Corporation, One Galaxy Way, Fort Worth Alliance Airport, Fort Worth, 
Texas 76177. The FAA concurs, and has revised this final rule 
accordingly.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 292 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 4 work hours per 
airplane to accomplish the required inspection, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of the inspection required by this AD on U.S. operators is 
estimated to be $70,080, or $240 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.
    Should an operator elect to accomplish the optional terminating 
action rather than continue the repetitive inspections, it would take 
approximately 4 work hours per airplane to accomplish the replacement, 
at an average labor rate of $60 per work hour. Required parts would 
cost approximately $44,350 per airplane. Based on these figures, the 
cost impact of this optional terminating action is estimated to be 
$44,590 per airplane.

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 adding the following new 
airworthiness directive:

98-05-09  Israel Aircraft Industries (IAI), Ltd.: Amendment 39-
10370. Docket 97-NM-166-AD.

    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 (e) 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 ensure that the trim actuator of the horizontal stabilizer 
operates properly, accomplish the following:
    (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 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 the effective date of 
this AD: Inspect within 50 flight hours after the effective date of 
this AD. 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

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accumulated less than 2,000 total flight cycles as of the effective 
date of this AD: Inspect at the times 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 the effective date of this AD. 
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 the effective date of this AD. 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.
    (c) As of the effective date of this AD, no horizontal 
stabilizer trim actuator shall be installed on any airplane unless 
that trim actuator has been inspected in accordance with the 
requirements of paragraph (a) of this AD.
    (d) Replacement of the trim actuator of the horizontal 
stabilizer with a modified trim actuator with modified jackscrew 
assemblies 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), as applicable; constitutes 
terminating action for the requirements of this AD.
    (e) 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 International Branch, ANM-116.

    (f) 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.
    (g) The actions shall be done in accordance with the following 
service bulletins, which contain the specified effective pages:

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                                     Page number                                                                
  Service bulletin referenced and      shown on      Revision level shown on page         Date shown on page    
                date                     page                                                                   
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Westwind, SB 1124-27-133, August             1-6  Original.........................  Aug. 14, 1996.             
 14, 1996.                                                                                                      
Westwind, SB 1124-27-133, Revision           1-4  1................................  May 28, 1997.              
 1, May 28, 1997.                                                                                               
                                            5, 6  Original.........................  Aug. 14, 1996.             
Westwind, SB 1123-27-046, August             1-6  Original.........................  Aug. 14, 1996.             
 14, 1996.                                                                                                      
Westwind, SB 1124-27-046, Revision           1-4  1................................  May 28, 1997.              
 1, May 28, 1997.                                                                                               
                                            5, 6  Original.........................  Aug. 14, 1996.             
Westwind, SB 1124-27-136, September          1-3  Original.........................  Sept. 1, 1997.             
 1, 1997.                                                                                                       
Westwind, SB 1123-27-047, September          1-3  Original.........................  Sept. 1, 1997.             
 1, 1997.                                                                                                       
Commodore Jet, SB 1121-27-025,               1-3  Original.........................  Dec. 22, 1997.             
 December 22, 1997.                                                                                             
Commodore Jet, SB 1121-27-023,               1-6  Original.........................  Aug. 14, 1996.             
 August 14, 1996.                                                                                               
Commodore Jet, SB 1121-27-023,               1-4  1................................  May 28, 1997.              
 Revision 1, May 28, 1997.                                                                                      
                                            5, 6  Original.........................  Aug. 14, 1996.             
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may 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 96-92, dated September 1, 1996.

    (h) This amendment becomes effective on April 10, 1998.

    Issued in Renton, Washington, on February 24, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-5348 Filed 3-5-98; 8:45 am]
BILLING CODE 4910-13-U