[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)]
[Proposed Rules]
[Pages 16170-16172]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8575]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-279-AD]
RIN 2120-AA64


Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-145 Series 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 EMBRAER Model EMB-145 
series airplanes. This proposal would require inspection of the main 
landing gear (MLG) bushing seats to detect cracks, and repair of the 
bushing hole or replacement of strut bushings with new bushings, if 
necessary. This proposal also would require replacement of the plain 
bearings of the MLG shock absorber with new bearings. This proposal is 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. The actions specified by 
the proposed AD are intended to prevent structural failure of the MLG 
due to fatigue cracking of the strut bushing seat.

DATES: Comments must be received by May 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-279-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 Empresa Brasileira de Aeronautica S.A. (EMBRAER), P.O. 
Box 343--CEP 12.225, Sao Jose dos Campos--SP, Brazil. This information 
may be examined at the FAA, Transport Airplane Directorate,

[[Page 16171]]

1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small 
Airplane Directorate, Atlanta Aircraft Certification Office, One Crown 
Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia.

FOR FURTHER INFORMATION CONTACT: Curtis A. Jackson, Aerospace Engineer, 
Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30337-2748; 
telephone (770) 703-6083; fax (770) 703-6097.

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 97-NM-279-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. 97-NM-279-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Departmento de Aviacao Civil (DAC), which is the airworthiness 
authority for Brazil, notified the FAA that an unsafe condition may 
exist on certain EMBRAER Model EMB-145 series airplanes. The DAC 
advises that, during fatigue testing of the main landing gear (MLG) 
strut, jamming of the plain bearing of the upper hinge point of the 
shock absorber occurred. This caused the bushings to turn and scratch 
the surface of the bushing seat of the MLG struts, and the initiation 
of a fatigue crack. Such fatigue cracking, if not detected and 
corrected in a timely manner, could result in structural failure of the 
MLG.

Explanation of Relevant Service Information

    EMBRAER has issued Service Bulletin 145-32-0012, dated September 1, 
1997, which describes procedures for a one-time liquid penetrant 
inspection to detect cracking of the flanged bushing seats of the main 
landing gear (MLG); a one-time inspection of the bushing holes using a 
bore micrometer to determine the dimension of the holes; and 
replacement of the strut bushings with new bushings, if necessary.
    In addition, EMBRAER has issued Service Bulletin 145-32-0009, dated 
September 1, 1997, which describes procedures for replacement of the 
plain bearings of the MLG shock absorber with new bearings. 
Accomplishment of the action specified in this service bulletin is 
intended to adequately address the identified unsafe condition.
    The DAC classified these service bulletins as mandatory and issued 
Brazilian airworthiness directive 97-10-02, dated October 13, 1997, in 
order to assure the continued airworthiness of these airplanes in 
Brazil.

FAA's Conclusions

    This airplane model is manufactured in Brazil 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 DAC has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
DAC, 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 Proposed 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, the proposed AD would require accomplishment of 
the actions specified in the service bulletins described previously, 
except as discussed below.

Differences Between Proposed Rule and Service Bulletins

    Operators should note that, although EMBRAER Service Bulletin 145-
32-0012, dated September 1, 1997, specifies that the manufacturer may 
be contacted for disposition of an oversized flanged bushing seat, this 
proposal would require repair of this condition to be accomplished in 
accordance with a method approved by the FAA.

Cost Impact

    The FAA estimates that 9 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 1 work 
hour per airplane to accomplish the proposed inspections, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the inspections proposed by this AD on U.S. operators is 
estimated to be $540, or $60 per airplane.
    The FAA estimates that it would take approximately 6 work hours per 
airplane to accomplish the proposed replacement of the plain bearings, 
at an average labor rate of $60 per work hour. Required parts would be 
provided by the manufacturer at no cost to operators. Based on these 
figures, the cost impact of the replacement proposed by this AD on U.S. 
operators is estimated to be $3,240, or $360 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    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

[[Page 16172]]

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 adding the following new 
airworthiness directive:

Empresa Brasileira de Aeronautica S.A. (EMBRAER): Docket 97-NM-279-
AD.

    Applicability: Model EMB-145 series airplanes, serial numbers 
145004 through 145018 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 (c) 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 structural failure of the main landing gear (MLG) due 
to fatigue cracking of the strut bushing seat, accomplish the 
following:
    (a) Prior to the accumulation of 2,000 total flight cycles, or 
within 100 flight cycles after the effective date of this AD, 
whichever occurs later, accomplish paragraphs (a)(1), (a)(2), and 
(a)(3) of this AD.
    (1) Perform a one-time liquid penetrant inspection to detect 
cracking of the flanged bushing seats of the MLG, in accordance with 
EMBRAER Service Bulletin 145-32-0012, dated September 1, 1997. If 
any crack is found, prior to further flight, repair in accordance 
with a method approved by the Manager, Atlanta Aircraft 
Certification Office (ACO), FAA, Small Airplane Directorate.
    (2) Perform a one-time inspection of the bushing holes using a 
bore micrometer to determine the dimension of the holes, in 
accordance with EMBRAER Service Bulletin 145-32-0012, dated 
September 1, 1997. Prior to further flight, accomplish paragraph 
(a)(2)(i) or (a)(2)(ii) of this AD, as applicable.
    (i) If the dimension of the bushing hole is less than 49.2 mm, 
perform the applicable corrective actions specified in the service 
bulletin.
    (ii) If the dimension of the bushing hole is greater than or 
equal to 49.2 mm, repair in accordance with a method approved by the 
Manager, Atlanta ACO.
    (3) Replace the plain bearing of the MLG shock absorber with a 
new bearing in accordance with EMBRAER Service Bulletin 145-32-0009, 
dated September 1, 1997.
    (b) As of the effective date of this AD, no person shall install 
a plain bearing having part number ABC24VG (NMB) on the shock 
absorber of the MLG of any airplane.
    (c) 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, Atlanta 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, Atlanta ACO.

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

    (d) 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.

    Note 3: The subject of this AD is addressed in Brazilian 
airworthiness directive 97-10-02, dated October 13, 1997.

    Issued in Renton, Washington, on March 25, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8575 Filed 4-1-98; 8:45 am]
BILLING CODE 4910-13-U