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[Federal Register Volume 62, Number 169 (Tuesday, September 2, 1997)]
[Rules and Regulations]
[Pages 46184-46186]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-23065]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-181-AD; Amendment 39-10118; AD 97-18-08]
RIN 2120-AA64

Airworthiness Directives; British Aerospace (Jetstream) Model 
4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain British Aerospace (Jetstream) Model 4101 
airplanes. This action requires a visual inspection to detect wear 
damage of the drag brace of the main landing gear (MLG), and 
replacement of any worn parts with new or serviceable parts. This 
action also requires an inspection to determine whether there is 
movement in the spherical bearing of the lower link of the drag brace, 
certain measurements of the drag brace, and repetitive inspections, if 
necessary. This amendment is prompted by reports of loose spherical 
bearings in the links of the drag brace of the MLG. The actions 
specified in this AD are intended to prevent reduced structural 
integrity and potential collapse of the

[[Page 46185]]

MLG due to loose spherical bearings and subsequent wear damage of the 
links of the drag brace.

DATES: Effective September 17, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 17, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before November 3, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-181-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
AI(R) American Support, Inc., 13850 Mclearen Road, Herndon, Virginia 
20171. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT: Mark Quam, Aerospace Engineer, ANM-
113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056; telephone (425) 227-2145; fax (425) 227-
1149.

SUPPLEMENTARY INFORMATION: 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 British Aerospace 
(Jetstream) Model 4101 airplanes. The CAA advises that it has received 
reports of loose spherical bearings in the lower link of the drag brace 
of the main landing gear (MLG). The loosened spherical bearings have 
been attributed to improper swaging on some landing gear units. Such 
loosened spherical bearings and subsequent wear damage of the links of 
the drag brace, if not detected and corrected, could result in reduced 
structural integrity and potential collapse of the MLG.

Explanation of Relevant Service Information

    British Aerospace has issued Jetstream Alert Service Bulletin J41-
A32-061, dated July 11, 1997, which describes procedures for performing 
a visual inspection to detect wear damage of the drag brace of the 
left-and right-hand MLG, and replacement of any worn part with a new or 
serviceable part. The alert service bulletin also describes procedures 
to detect any movement of the spherical bearing and to measure the 
lower link to the upper link and the lower link to the strut attachment 
of the drag brace, and repetitive inspections, if necessary.
    Additionally APPH Ltd. has issued APPH Service Bulletin AIR84352-
32-05, dated June 1997, which describes procedures for an inspection to 
detect movement of the spherical bearings installed in the lower links 
of the drag braces of the MLG, and rework, if necessary. The CAA has 
approved APPH Service Bulletin AIR84352-32-05, and has classified 
Jetstream Alert Service Bulletin J41-A32-061 as mandatory, and issued 
British airworthiness directive 003-07-97, dated July 25, 1997, in 
order to assure the continued airworthiness of these airplanes in the 
United Kingdom.

FAA's Conclusions

    This airplane model is manufactured in the United Kingdom and is 
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 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.

Explanation of Requirements of 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, this AD is being issued to prevent reduced 
structural integrity and potential collapse of the MLG due to loose 
spherical bearings in the links of the drag brace, which could result 
in wear damage to the drag brace of the MLG. This AD requires a visual 
inspection to detect wear damage of the drag brace of the MLG, and 
replacement of any worn parts with new or serviceable parts. This AD 
also requires an inspection to determine whether there is movement in 
the spherical bearing of the lower link of the drag brace, certain 
measurements of the drag brace, and repetitive inspections, if 
necessary. The actions are required to be accomplished in accordance 
with the Jetstream alert service bulletin described previously.

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 97-NM-181-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

[[Page 46186]]

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 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:

97-18-08 British Aerospace Regional Aircraft [Formerly Jetstream 
Aircraft Limited, British Aerospace (Commercial Aircraft) Limited]: 
Amendment 39-10118. Docket 97-NM-181-AD.

    Applicability: Jetstream Model 4101 airplanes, constructors 
numbers 41004 through 41100 inclusive, 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 reduced structural integrity and potential collapse 
of the main landing gear (MLG) due to loose spherical bearings of 
the drag brace, accomplish the following:
    (a) For all airplanes: Within 30 days after the effective date 
of this AD, perform a visual inspection to detect wear damage of the 
drag brace of the left- and right-hand MLG, in accordance with 
Jetstream Alert Service Bulletin J41-A32-061, dated July 11, 1997.
    (1) For airplanes on which no wear damage has been detected and 
that have accumulated 8,000 or more total landings as of the 
effective date of this AD or on which APPH Service Bulletin 
AIR84352-32-05 has been accomplished: Prior to further flight, 
perform an inspection to detect movement of the spherical bearing of 
the drag brace and measure the area between the lower link and the 
strut, in accordance with the Jetstream alert service bulletin.
    (i) If no movement of the spherical bearing is detected and the 
measurement of the area between the lower link and the strut is 
within the limits specified by the service bulletin, no further 
action is required by this AD.

    Note 2: For the purposes of this AD, ``flight day'' is defined 
as any day on which the airplane is flown.

    (ii) If any movement is detected or the measurement of the area 
between the lower link and the strut is beyond the limits specified 
by the service bulletin, repeat the inspections required by 
paragraph (a) of this AD prior to the first flight of the day for 
the next 100 flight days of the airplane.
    (2) For all other airplanes on which no wear damage has been 
detected: Prior to further flight, perform an inspection to detect 
movement of the spherical bearing of the drag brace and measure the 
area between the lower link and the strut, in accordance with the 
service bulletin.
    (i) If no movement of the spherical bearing is detected, and the 
measurement of the area between the lower link and the strut is 
within the limits specified by the service bulletin, repeat the 
inspections required by paragraph (a) of this AD at the time 
specified in paragraph (a)(2)(i)(A) or (a)(2)(i)(B) of this AD, as 
applicable.
    (A) For drag braces that have accumulated less than 501 total 
landings: Repeat the inspections at intervals not to exceed 100 
flights until the drag brace has accumulated 500 total landings.
    (B) For drag braces that have accumulated more than 500 total 
landings, but less than 8,000 total landings: Repeat the inspections 
at intervals not to exceed 1,000 flights.
    (ii) If any movement is detected or the measurement of the area 
between the lower link and the strut is beyond the limits specified 
by the service bulletin, repeat the inspections required by 
paragraph (a) of this AD prior to the first flight of the day for 
the next 100 flight days of the airplane.
    (b) For all airplanes: If any wear damage of the drag brace is 
detected during any inspections required by this AD, prior to 
further flight, remove the wear damaged part(s) and replace with a 
new or serviceable part, in accordance with Jetstream Alert Service 
Bulletin J41-A32-061, dated July 11, 1997. Within 30 days after the 
replacement of a wear damaged part with a new or serviceable part, 
perform the requirements of paragraph (a) of this AD.
    (c) Accomplishment of APPH Service Bulletin AIR84352-32-05, 
dated June 1997, constitutes terminating action for the repetitive 
inspection requirements of paragraph (a)(2) of 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, Standardization Branch, ANM-113. 
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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (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.
    (f) The actions shall be done in accordance with Jetstream Alert 
Service Bulletin J41-A32-061, dated July 11, 1997. 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 AI(R) American Support, Inc., 13850 
Mclearen Road, Herndon, Virginia 20171. 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.
    (g) This amendment becomes effective on September 17, 1997.

    Issued in Renton, Washington, on August 25, 1997.
Gary L. Killion,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-23065 Filed 8-29-97; 8:45 am]
BILLING CODE 4910-13-P
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