[Federal Register Volume 65, Number 5 (Friday, January 7, 2000)]
[Proposed Rules]
[Pages 1075-1076]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-377]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-229-AD]
RIN 2120-AA64


Airworthiness Directives; Cessna Model 750 Citation X Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM); rescission.

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SUMMARY: This document proposes to rescind an existing airworthiness 
directive (AD), applicable to all Cessna Model 750 Citation X series 
airplanes, that currently requires repetitive in-flight functional 
tests to verify proper operation of the secondary horizontal stabilizer 
pitch trim system, and repair, if necessary. The actions specified by 
that AD are intended to detect and correct such contamination and 
damage, which could result in simultaneous failure of both primary and 
secondary pitch trim systems, and consequent reduced controllability of 
the airplane. Since the issuance of that AD, an improved part has been 
developed, which, if installed, would terminate the repetitive tests; 
that improved part has been installed on all affected airplanes or is 
being installed in production. Therefore, the identified unsafe 
condition no longer exists.

DATES: Comments must be received by February 22, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-229-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.
    Information pertaining to this proposed rule may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Joel M. Ligon, Aerospace Engineer, 
Systems and Propulsion Branch, ACE-116W, FAA, Small Airplane 
Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, 
Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 
946-4138; fax (316) 946-4407.

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 99-NM-229-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. 99-NM-229-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On July 29, 1998, the FAA issued AD 98-16-17, amendment 39-10693 
(63 FR 42206, August 7, 1998), applicable to all Cessna Model 750 
Citation X series airplanes, to require repetitive in-flight functional 
tests to verify proper operation of the secondary horizontal stabilizer 
pitch trim system, and repair, if necessary. That action was prompted 
by reports of simultaneous failures of the primary and secondary 
horizontal stabilizer pitch trim system during flight, due to internal 
water contamination and corrosion damage in the system actuator. The 
requirements of that AD are intended to detect and correct such 
contamination and damage, which could result in simultaneous failure of 
both primary and secondary pitch trim systems, and consequent reduced 
controllability of the airplane.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the manufacturer has developed a 
modification (reference Cessna Service Bulletin SB750-27-23, dated 
February 2, 1999) that involves replacement of the horizontal 
stabilizer trim system actuator with an improved actuator incorporating 
a moisture condenser. The improved design will prevent internal water 
contamination and corrosion damage of the actuator. The FAA has 
determined that installation of this improved actuator will adequately 
address the unsafe condition identified in AD 98-16-17, and will 
eliminate the need for the repetitive in-flight functional tests 
required by that AD.
    The manufacturer has verified that the modification has been 
accomplished on all affected airplanes, including those in production, 
and on all actuators in operators' inventories. Therefore, the unsafe 
condition cannot be reintroduced into the fleet.

FAA's Conclusions

    Since all affected airplanes, including those in production, and 
all actuators in operators' inventories have been modified, the FAA has 
determined that it is necessary to rescind AD 98-16-17 in order to 
prevent operators from performing an unnecessary action.
    This proposed action would rescind AD 98-16-17. Rescission of AD 
98-16-17 would constitute only such action, and, if followed by a final 
action, would not preclude the agency from issuing another notice in 
the future, nor would it commit the agency to any course of action in 
the future.

Cost Impact

    The FAA estimates that 52 airplanes of U.S. registry are affected 
by AD 98-

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16-17. The actions that are currently required by that AD take 
approximately 2 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 $6,240, or $120 per airplane. However, the adoption of this 
proposed rescission would eliminate those costs.

Regulatory Impact

    The regulations proposed herein would 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 39-10693.

Cessna Aircraft Company: Docket 99-NM-229-AD. Rescinds AD 98-16-17, 
Amendment 39-10693.
    Applicability: All Model 750 Citation X series airplanes, 
certificated in any category.

    Issued in Renton, Washington, on January 3, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-377 Filed 1-6-00; 8:45 am]
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