[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
