[Federal Register Volume 60, Number 243 (Tuesday, December 19, 1995)]
[Proposed Rules]
[Pages 65258-65260]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-30747]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-133-AD]


Airworthiness Directives; Jetstream Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Jetstream Model 4101 
airplanes. This proposal would require replacement of the flexible 
cables of the power and condition controls of the engines with new 
flexible cables. The proposal would also require installation of 
protective tape on the outside case of these flexible cables, and 
reidentification of the cables. This proposal is prompted by reports of 
stiff operation of the power and condition controls of the engines due 
to heat damage to and moisture contamination of the flexible cable. The 
actions specified by the proposed AD are intended to prevent heat 
damage and moisture contamination to the flexible cable, which could 
result in stiff operation of the power and condition controls and 
subsequent reduced engine control.

DATES: Comments must be received by January 25, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-133-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 

[[Page 65259]]
Jetstream Aircraft, Inc., P.O. Box 16029, Dulles International Airport, 
Washington, DC 20041-6029. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; fax (206) 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 95-NM-133-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-103, Attention: Rules 
Docket No. 95-NM-133-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on certain Jetstream Model 4101 airplanes. 
The CAA advises that it has received reports of stiff operation of the 
power and condition controls of the engines on these airplanes. 
Investigation revealed that a protective sheath on the flexible cables 
can become damaged by heat, which allows water to enter the flexible 
cable. The water may then drain along the flexible cable to the cold 
area in the leading edge of the wing and freeze. These conditions, if 
not corrected, could result in stiff operation of the power and 
condition controls, and subsequent reduced engine control.
    Jetstream has issued Service Bulletin J41-76-013, dated May 5, 
1995, which describes procedures for checking the aircraft records to 
determine if any reports of stiff operation in freezing conditions have 
been recorded. The service bulletin also describes procedures for 
replacement of the flexible cables of power and condition controls of 
the engines with new flexible cables. The service bulletin also 
describes procedures for installation of protective tape on the outside 
case of the flexible cables of the power and condition controls of the 
engines, and reidentification of the assembly number of the cable. The 
service bulletin specifies that both the replacement of the flexible 
cables and installation of protective tape need to be accomplished on 
certain airplane, but specifies that only the protective tape 
installation needs to be accomplished on certain other airplanes. The 
CAA classified this service bulletin as mandatory in order to assure 
the continued airworthiness of these airplanes in the United Kingdom.
    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) and the applicable bilateral airworthiness agreement. Pursuant 
to this bilateral airworthiness agreement, the CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA, 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.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, the 
proposed AD would require replacement of the flexible cables of power 
and condition controls of the engines with new flexible cables. The 
proposed AD would also require simultaneous installation of protective 
tape on the outside case of the new flexible cables of the power and 
condition controls of the engines, and reidentification of the assembly 
number of the cable. The actions would be required to be accomplished 
in accordance with the procedures contained in the service bulletin 
described previously.
    Operators should note that, unlike the recommendations of the 
service bulletin, the proposed AD would not require checking the 
aircraft records to determine if any reports of stiff operation in 
freezing conditions have been recorded. The FAA finds that the Airplane 
Maintenance Log is the appropriate source of aircraft records for 
reports of stiff operation of the power and condition controls. 
However, operators are not required to retain these records [reference 
part 121 or 135 of the Federal Aviation Regulations (FAR) (14 CFR 121 
or 135).]. Therefore, the FAA has determined that these aircraft 
records may not be available for review by maintenance personnel if 
attempting to comply with a requirement to accomplish such a review.
    Operators should also note that, unlike the recommendations of the 
service bulletin, the proposed AD would require that the replacement of 
the flexible cables and installation of the protective tape be 
accomplished on all affected airplanes. The FAA finds that damage to 
the flexible cable sheath and subsequent moisture contamination to the 
flexible cables may still exist or develop even though there have been 
no previous reports of stiff operation of the power and condition 
controls. Airplanes with moisture contamination in the flexible cables 
may not yet have encountered the environmental conditions necessary to 
freeze the moisture and subsequently cause stiff operation. Therefore, 
the FAA has determined that accomplishing only the installation of the 
protective tape on cables (if no stiff operations have been reported) 
would not eliminate the unsafe condition, since water contamination of 
the flexible cable may still exist.
    The FAA estimates that 25 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 11 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
supplied by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $16,500, or $660 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would 

[[Page 65260]]
accomplish those actions in the future if this AD were not adopted.
    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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended] -

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Jetstream Aircraft Limited: Docket 95-NM-133-AD.

    -Applicability: Model 4101 airplanes on which Jetstream 
Modification JM41478 or JM41485A has not been installed, 
certificated in any category.

    -Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 use the authority 
provided in paragraph (b) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD. -
    Compliance: Required as indicated, unless accomplished 
previously. -
    To prevent heat damage and moisture contamination to the 
flexible cable, which could result in stiff operation of the power 
and condition controls and subsequent reduced engine control, 
accomplish the following: -
    (a) Within 6 months after the effective date of this AD, 
accomplish the requirements of paragraphs (a)(1) and (a)(2) of this 
AD, in accordance with Jetstream Service Bulletin J41-76-013, dated 
May 5, 1995. Both requirements must be accomplished at the same 
time.
    (1) Replace the flexible cables of power and condition controls 
of the left and right engines with new flexible cables, in 
accordance with paragraphs 2.B. and 2.C. of the Accomplishment 
Instructions of the service bulletin; and -
    (2) Install protective tape on the outside case of the flexible 
cables of the power and condition controls of the left and right 
engines; and reidentify the assembly number of the cable; in 
accordance with paragraph 2.D. of the Accomplishment Instructions of 
the service bulletin. -
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    -Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    -(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.

    Issued in Renton, Washington, on December 13, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-30747 Filed 12-18-95; 8:45 am]
BILLING CODE 4910-13-U