[Federal Register Volume 63, Number 152 (Friday, August 7, 1998)]
[Rules and Regulations]
[Pages 42206-42208]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20836]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-208-AD; Amendment 39-10693; AD 98-16-17]
RIN 2120-AA64


Airworthiness Directives; Cessna Model 750 Citation X Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Cessna Model 750 Citation X series airplanes. This 
action requires repetitive in-flight functional tests to verify proper 
operation of the secondary horizontal stabilizer pitch trim system, and 
repair, if necessary. This amendment is 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 actions 
specified in this AD are intended to detect and correct

[[Page 42207]]

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.

DATES: Effective August 24, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 24, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before October 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-208-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
Cessna Aircraft Co., P.O. Box 7706, Wichita, Kansas 67277. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small 
Airplane Directorate, Wichita Aircraft Certification Office, 1801 
Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

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: The FAA recently received reports of 
simultaneous primary and secondary horizontal stabilizer pitch trim 
system failures during flight on Cessna Model 750 Citation X series 
airplanes. Inspection of the horizontal stabilizer pitch trim actuators 
utilized for both primary and secondary pitch trim has revealed 
evidence of internal water contamination and corrosion damage. This 
condition may be caused by water being ingested into the actuator due 
to condensation during airplane descent from high altitude into a warm, 
humid environment. Subsequent testing by the manufacturer has verified 
that the trapped water may freeze in the actuator mechanism and disable 
actuation of both primary and secondary trim. It has been determined 
that the actuator case seal, as applied to some actuators, may be 
ineffective at preventing internal water contamination and corrosion 
damage. Such contamination and damage, if not corrected, could result 
in simultaneous failure of both primary and secondary trim system, and 
consequent reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Cessna Alert Service Bulletin 
ASB750-27-22, dated July 2, 1998, which describes procedures for 
repetitive in-flight functional tests to verify proper operation of the 
secondary horizontal stabilizer pitch trim system. (Such functional 
testing of the primary horizontal stabilizer pitch trim system is 
currently addressed in the FAA-approved Airplane Flight Manual and FAA-
approved maintenance procedures for these airplanes.) For airplanes on 
which the functional test fails, the alert service bulletin also 
describes procedures for inspection of the actuator components and 
clutch assemblies for evidence of internal water contamination in the 
system actuator and corrosion damage; and repair, if necessary.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent failure of both primary and secondary pitch 
trim systems due to internal water contamination and corrosion damage 
in the system actuator, which could result in reduced controllability 
of the airplane. This AD requires accomplishment of the actions 
specified in the alert service bulletin described previously.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-208-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final

[[Page 42208]]

regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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:

98-16-17  Cessna Aircraft Company: Amendment 39-10693. Docket 98-NM-
208-AD.

    Applicability: All Model 750 Citation X 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 (b) 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 detect and correct internal water contamination and corrosion 
damage of the secondary horizontal stabilizer trim actuator, which 
could result in simultaneous failure of both primary and secondary 
pitch trim systems, and consequent reduced controllability of the 
airplane, accomplish the following:
    (a) Within 10 days after the effective date of this AD, perform 
an in-flight functional test to verify proper operation of the 
secondary horizontal stabilizer pitch trim system, in accordance 
with Cessna Alert Service Bulletin ASB750-27-22, dated July 2, 1998.
    (1) If the secondary trim system does not fail during the in-
flight functional test, repeat the action thereafter at intervals 
not to exceed 30 days.
    (2) If the secondary trim system fails during the in-flight 
functional test, prior to next flight, inspect the actuator 
components and clutch assemblies for evidence of internal water 
contamination or corrosion damage in accordance with the alert 
service bulletin. If any evidence of internal water contamination or 
corrosion damage is detected, prior to further flight, repair in 
accordance with the alert service bulletin. Repeat the in-flight 
functional test thereafter at intervals not to exceed 30 days.
    (b) 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, Wichita Aircraft Certification 
Office (ACO), FAA, Small 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, Wichita ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Wichita ACO.

    (c) 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.
    (d) The actions shall be done in accordance with Cessna Alert 
Service Bulletin ASB750-27-22, dated July 2, 1998. 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 Cessna Aircraft Co., P.O. Box 7706, 
Wichita, Kansas 67277. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the FAA, Small Airplane Directorate, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, Kansas; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on August 24, 1998.

    Issued in Renton, Washington, on July 29, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-20836 Filed 8-6-98; 8:45 am]
BILLING CODE 4910-13-U