[Federal Register Volume 69, Number 66 (Tuesday, April 6, 2004)]
[Proposed Rules]
[Pages 17984-17986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-7713]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-79-AD]
RIN 2120-AA64


Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. 
(EMBRAER) Model EMB-120 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-120 
series airplanes. This proposal would require repetitive inspections 
for cracks or evidence of damage/distortion of the anti-skid drive 
coupling clips for the hubcaps of the main landing gear (MLG) wheels; 
repetitive measurement of the gap and height dimensions of the coupling 
clips; corrective actions, if necessary; and eventual replacement of 
all coupling clips with new, improved coupling clips. This action is 
necessary to prevent excessive gaps in the anti-skid drive coupling 
clips for the hubcaps of the MLG, which could result in momentary loss 
of the normal braking system at low speeds, and reduced controllability 
of the airplane. This action is intended to address the identified 
unsafe condition.

DATES: Comments must be received by May 6, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-79-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-79-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,

[[Page 17985]]

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-79-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-79-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-120 series airplanes. The DAC 
advises that it received reports of momentary loss of normal braking 
during low speed taxiing. In two of the reported incidents there was a 
complete loss of normal braking in all four main landing gear (MLG) 
wheels. Investigation revealed an excessive gap in the anti-skid drive 
coupling clips for the hubcaps of the inboard and outboard MLG wheels. 
These excessive gaps may impair the proper coupling of the clips with 
the anti-skid wheel speed transducer shaft, causing a temporary loss of 
normal braking in all four main wheels. This condition, if not 
corrected, could result in momentary loss of the normal braking system 
at low speeds and reduced controllability of the airplane.

Explanation of Relevant Service Information

    EMBRAER has issued Service Bulletin 120-32-0088, Revision 01, dated 
October 1, 2003, which describes procedures for the following actions:
     A visual inspection for cracks, damage, 
distortion or broken-off pieces of the anti-skid drive coupling clips 
for the hubcaps of the inboard and MLG wheels.
     Measurement of the ``G'' (gap) and ``H'' 
(height) dimensions of the coupling clips to ensure they are within the 
tolerances specified in Figure 1 of the service bulletin; and 
repetitive measurement of dimension ``G'' at every wheel or transducer 
change.
     For certain airplanes, a one-time re-inspection 
of the anti-skid drive coupling clips for the affected MLG wheel hubcap 
at the next MLG wheel change, per Part II of the service bulletin.
    The service bulletin also describes procedures for the following 
corrective actions:
     Replacement of any coupling clip having evidence 
of cracks, damage, distortion, or broken-off pieces; or having a 
measurement of dimension ``H'' that is outside the specified tolerance; 
with a new, improved part.
     Adjustment of any clip with dimension ``G'' 
outside the specified tolerance.
     Replacement of any clip where dimension ``G'' 
cannot be adjusted to the specified tolerance.
     Eventual replacement of all coupling clips with 
new, improved clips at the next C-check.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition. The DAC 
classified this service bulletin as mandatory and issued Brazilian 
airworthiness directive 2003-01-01, dated February 6, 2003, to ensure 
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 us informed of the 
situation described above. We have 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 AD

    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 bulletin described previously, 
except as discussed below.

Difference Between the Brazilian Airworthiness Directive, the Service 
Bulletin, and the Proposed AD

    Paragraph (c) of the Brazilian airworthiness directive recommends 
that no later than March 30, 2003, the installation procedures for the 
MLG be revised to include a mandatory visual inspection for cracks, 
evident damage, distortion or broken-off pieces, of the anti-skid drive 
coupling clips for the MLG wheel hubcap; and a complete clip 
dimensional verification including the gap and the height. This 
proposed AD does not include a requirement to revise the installation 
procedures for the MLG wheels. However, paragraph (a) of this proposed 
AD does require repetitive general visual inspections and repetitive 
measurements of dimensions ``G'' and ``H'' of the anti-skid drive 
coupling at every wheel change or wheel speed transducer change.
    The service bulletin states that if the measurement of dimension 
``G'' of any anti-skid drive coupling clip is out of the tolerance 
specified in the service bulletin, and the clip can be adjusted to the 
specified tolerance, one re-inspection is necessary at the next MLG 
wheel change per Part II of the service bulletin. The service bulletin 
also contains a note stating that dimension ``G'' should be checked at 
every wheel or transducer change. This proposed AD does not include 
such a requirement;

[[Page 17986]]

however, as previously mentioned, paragraph (a) of this proposed AD 
does require repetitive measurements of dimensions ``G'' and ``H'' of 
the anti-skid drive coupling at every wheel change or wheel speed 
transducer change.

Clarification of Inspection Terminology

    The service bulletin specifies a visual inspection of the MLG wheel 
hubcap clips for cracks, evident damage, distortion, or broken-off 
pieces. This proposed AD requires a general visual inspection. A note 
has been added to define that inspection.

Cost Impact

    We estimate that 220 airplanes of U.S. registry would be affected 
by this proposed AD.
    It would take approximately 2 work hours per airplane to do the 
proposed general visual inspection and measurement of dimensions ``G'' 
and ``H'', at an average labor rate of $65 per work hour. Based on 
these figures, the cost impact of the proposed actions on U.S. 
operators is estimated to be $28,600, or $130 per airplane, per 
inspection cycle.
    It would take approximately 1 work hour per airplane to do the 
proposed replacement of the coupling clips, at an average labor rate of 
$65 per work hour. Required parts would cost approximately $600 per 
airplane. Based on these figures, the cost impact of the proposed 
action on U.S. operators is estimated to be $146,300, or $665 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. 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.

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-79-
AD.

    Applicability: Model EMB-120 series airplanes having serial 
numbers 120003, 120004, and 120006 through 120359 inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent excessive gaps in the anti-skid drive coupling clips 
for the hubcaps of the main landing gear (MLG), which could result 
in momentary loss of the normal braking system at low speeds, and 
reduced controllability of the airplane, accomplish the following:

General Visual Inspection, Measurement of Clip Dimensions, and 
Corrective Actions

    (a) Within 400 flight hours or 6 months after the effective date 
of this AD, whichever occurs first: Do a general visual inspection 
for cracks or evidence of damage/distortion of the anti-skid drive 
coupling clips for the MLG wheel hubcap; and measure the ``G'' (gap) 
and ``H'' (height) dimensions of the coupling clips; and do any 
applicable corrective action; per the Accomplishment Instructions of 
EMBRAER Service Bulletin 120-32-0088, Revision 01, dated October 1, 
2003. Any applicable corrective action must be done prior to further 
flight per the service bulletin. Repeat the inspection and dimension 
measurement thereafter at every wheel change or wheel speed 
transducer change.

    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Replacement of Coupling Clips

    (b) Within 800 flight hours or 12 months after the effective 
date of this AD, whichever occurs first: Replace any anti-skid drive 
coupling clip for the MLG wheel hubcap that was not previously 
replaced per paragraph (a) of this AD, with a new, improved part 
specified in and per Part III of EMBRAER Service Bulletin 120-32-
0088, Revision 01, dated October 1, 2003. Repeat the applicable 
actions required by paragraph (a) of this AD thereafter at every 
wheel change or wheel speed transducer change.

Parts Installation

    (c) As of the effective date of this AD, no person may install 
an anti-skid drive coupling clip, part number 40-91115, on any 
airplane, unless the part number is identified as 40-91115 REV. D.

Credit for Actions Done per Previous Issue of Service Bulletin

    (d) Accomplishment of the specified actions before the effective 
date of this AD per EMBRAER Service Bulletin 120-32-0088, dated 
November 18, 2002, is considered acceptable for compliance with the 
applicable requirements of paragraphs (a) and (b) of this AD.

Alternative Methods of Compliance

    (e) 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 2: The subject of this AD is addressed in Brazilian 
airworthiness directive 2003-01-01, dated February 6, 2003.


    Issued in Renton, Washington, on March 30, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-7713 Filed 4-5-04; 8:45 am]
BILLING CODE 4910-13-P