[Federal Register Volume 69, Number 140 (Thursday, July 22, 2004)]
[Proposed Rules]
[Pages 43777-43779]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-16681]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-85-AD]
RIN 2120-AA64


Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-135 and EMB-145 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain EMBRAER Model EMB-135 and EMB-145 
series airplanes, that would have required inspection of the housings 
of the main landing gear (MLG) leg strut bushings; repair of the 
housings if necessary; and replacement of the MLG leg strut bushings 
with new bushings. This new action revises the proposed rule by 
requiring inspection of additional MLG leg strut bushings; removing the 
requirement to replace the MLG leg strut bushings; and clarifying that 
related investigative and corrective actions must be accomplished. The 
actions specified by this new proposed AD are intended to prevent 
corrosion of the housings of the MLG leg strut bushings and consequent 
failure of the MLG. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by August 16, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-85-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-85-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 or 
ASCII text.
    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, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer; 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2125; fax (425) 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2003-NM-85-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. 2003-NM-85-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain EMBRAER Model EMB-135 and EMB-145 series airplanes, was 
published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on December 31, 2003 (68 FR 75468). That NPRM would have 
required inspection of the housings of the main landing gear (MLG) leg 
strut bushings; repair of the housings if necessary; and replacement of 
the MLG leg strut bushings with new bushings. That NPRM was prompted by 
a report that corrosion was discovered

[[Page 43778]]

on the housings of certain MLG leg strut bushings due to water 
accumulation in the holes of those bushings. That condition, if not 
corrected, could result in failure of the MLG.

Explanation of New Relevant Service Information

    Since the issuance of the original NPRM, EMBRAER has issued Service 
Bulletin 145-32-0066, Change 03, dated April 19, 2004. (The original 
NPRM refers to Change 01 of that service bulletin, dated August 15, 
2002, as the appropriate source of service information for the proposed 
actions.) Change 03 of the service bulletin identifies additional part 
numbers and serial numbers of MLG leg struts that are affected by that 
service bulletin. Change 03 of the service bulletin describes 
procedures for an inspection for corrosion of the housings of the MLG 
leg strut bushings; and related investigative and corrective actions; 
which are similar to those described in Change 01 of the service 
bulletin. The procedures for investigative and corrective actions 
include removing any corrosion; enlarging the diameter of the bushing 
housing, if necessary; performing a dye-penetrant inspection of the 
housings for further sign of corrosion, if necessary; reworking and 
installing the bushings; and applying corrosion-inhibiting compound to 
the bushing housings. The Departmento de Aviacao Civil, which is the 
airworthiness authority for Brazil, has approved this service bulletin.
    EMBRAER Service Bulletin 145-32-0066, Change 03, refers to Embraer 
Liebherr Equipamentos do Brasil S.A. (ELEB) Service Bulletin 2309-2006-
32-01, Revision 03, dated April 19, 2004, as an additional source of 
service information for the inspection and repair of the MLG leg strut 
bushings. The ELEB service bulletin is included within the EMBRAER 
service bulletin.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. The FAA has duly considered the 
comments received.

Request To Revise Applicability Statement

    Several commenters request that we revise the applicability 
statement of the original NPRM to eliminate certain airplane serial 
numbers. The commenters note that defining the applicability in terms 
of installed MLG leg strut part numbers results in airplanes that are 
not affected by the original NPRM being included in the applicability. 
The commenters point out that the bushing housings on certain airplane 
serial numbers have already received corrosion protection, and thus 
should not be subject to the proposed actions. Other airplane serial 
numbers have received, in production, a modification equivalent to that 
in EMBRAER Service Bulletin 145-32-0066, Change 01.
    We partially agree with the commenters' requests. We agree to 
revise the manner in which the applicability is stated in this 
supplemental NPRM, so that it more closely matches the effectivity of 
the service bulletin. Thus, instead of listing the affected MLG leg 
strut part numbers, the applicability statement of this supplemental 
NPRM refers to the table under the heading ``Affected component'' in 
paragraph 1.B., ``Effectivity,'' of EMBRAER Service Bulletin 145-32-
0066, Change 03, as the source for affected MLG leg strut part and 
serial numbers.
    However, we do not agree to revise the applicability statement to 
exclude certain airplane serial numbers. The service bulletin notes 
that the MLG leg struts are line replaceable units. Thus, an affected 
MLG leg strut may have been removed from the airplane on which it was 
delivered and subsequently installed on an airplane outside the serial 
number range specified in the service bulletin.

Request To Remove Replacement Requirement

    One commenter, the airplane manufacturer, requests that we remove 
the requirement to replace the MLG leg strut bushings, which is 
specified in paragraph (b) of the original NPRM. The commenter states 
that the new bushings are not necessary to prevent corrosion because, 
although water can accumulate in the holes of the leg strut bushings, 
the primary cause of the unsafe condition is lack of corrosion 
protection in the housings. Thus, the application of corrosion 
protection in the housings, as described in the service bulletin, 
eliminates the need to replace the bushings. We concur and have omitted 
paragraph (b) of the original NPRM from this supplemental NPRM.

Request To Provide Credit for Actions Accomplished Previously

    One commenter requests that we revise the original NPRM to give 
credit for accomplishment of the proposed actions per EMBRAER Service 
Bulletin 145-32-0066, dated January 8, 2002.
    We concur. We have reviewed the original issue of the service 
bulletin and find that the procedures therein are substantively similar 
to those in Change 01. Accordingly, we have added a new paragraph (b) 
to this supplemental NPRM to give credit for actions accomplished 
before the effective date of the AD per the original issue, Change 01, 
or Change 02 of the service bulletin. (As explained previously, 
paragraph (b) of the original NPRM has been omitted from this 
supplemental NPRM. Thus, adding a new paragraph (b) does not 
necessitate the re-identification of subsequent paragraphs.)

Explanation of Additional Change to Original NPRM

    We have revised paragraph (a) of the original NPRM to clarify that, 
if no corrosion is found, all applicable actions specified in the 
service bulletin (e.g., applying corrosion-inhibiting compound) must be 
done to comply with the intent of the proposed AD.
    We have also revised the estimated number of work hours stated in 
the Cost Impact section of this supplemental NPRM from 7 to 14, to 
reflect the estimate contained in the EMBRAER service bulletin.

Conclusion

    Since certain changes described previously expand the scope of the 
originally proposed rule, we have determined that it is necessary to 
reopen the comment period to provide additional opportunity for public 
comment.

Cost Impact

    We estimate that 75 airplanes of U.S. registry would be affected by 
this proposed AD.
    It would take approximately 14 work hours per airplane to 
accomplish the proposed inspection of the bushing housings for 
corrosion, at an average labor rate of $65 per work hour. Based on 
these figures, the cost impact of the proposed inspection on U.S. 
operators is estimated to be $68,250, or $910 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 accomplish those actions in 
the future if this AD were not adopted. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

[[Page 43779]]

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 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 2003-NM-85-
AD.

    Applicability: Model EMB-135 and EMB-145 series airplanes, 
certificated in any category, equipped with a main landing gear 
(MLG) leg strut having a part number (P/N) and serial number (S/N) 
listed in the table under the heading ``Affected component'' in 
paragraph 1.B., ``Effectivity,'' of EMBRAER Service Bulletin 145-32-
0066, Change 03, dated April 19, 2004.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent corrosion of the housings of the main landing gear 
(MLG) leg strut bushings and consequent failure of the MLG, 
accomplish the following:

Inspection and Investigative and Corrective Actions

    (a) Within 5,500 flight hours after the effective date of this 
AD, perform a detailed inspection of the housings of the MLG leg 
strut bushings for corrosion per the Accomplishment Instructions of 
EMBRAER Service Bulletin 145-32-0066, Change 03, dated April 19, 
2004.
    (1) If no corrosion is found, before further flight, do all 
applicable actions in and per the Accomplishment Instructions of the 
service bulletin.
    (2) If any corrosion is found, before further flight, do all 
applicable investigative and corrective actions in and per the 
Accomplishment Instructions of the service bulletin.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''


    Note 2: EMBRAER Service Bulletin 145-32-0066, Change 03, dated 
April 19, 2004, refers to Embraer Liebherr Equipamentos do Brasil 
S.A. (ELEB) Service Bulletin 2309-2006-32-01, Revision 03, dated 
April 19, 2004, as an additional source of service information for 
the inspection and repair of the MLG leg strut bushings. The ELEB 
service bulletin is included within the EMBRAER service bulletin.

Inspections Accomplished Per Previous Issue of Service Bulletin

    (b) Inspections and related investigative and corrective actions, 
accomplished before the effective date of this AD per EMBRAER Service 
Bulletin 145-32-0066, dated January 8, 2002; Change 01, dated August 
15, 2002; or Change 02, dated February 26, 2004; are considered 
acceptable for compliance with the corresponding action specified in 
this AD.

Alternative Methods of Compliance

    (c) In accordance with 14 CFR 39.19, the Manager, International 
Branch, ANM-116, Transport Airplane Directorate, FAA, is authorized to 
approve alternative methods of compliance for this AD.

    Note 3: The subject of this AD is addressed in Brazilian 
airworthiness directive 2002-12-01, effective January 6, 2003.


    Issued in Renton, Washington, on July 9, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-16681 Filed 7-21-04; 8:45 am]
BILLING CODE 4910-13-P