[Federal Register Volume 63, Number 59 (Friday, March 27, 1998)]
[Proposed Rules]
[Pages 14855-14857]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8097]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-33-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 all EMBRAER Model EMB-120 series 
airplanes. This proposal would require a one-time inspection for 
delamination, erosion, and condition of fillet sealant and conductive 
edge sealer of the wing and empennage leading edge area behind the de-
ice boots, and follow-on corrective actions. 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 delamination of the wing and 
empennage leading edge due to improper installation of the wing de-ice 
boot, which could result in reduced controllability of the airplane.

DATES: Comments must be received by April 27, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-33-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, 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: Rob Capezzuto, Aerospace Engineer, 
Systems and Flight Test Branch, ACE-116A, FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30337-2748; 
telephone (770) 703-6071; 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

[[Page 14856]]

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 98-NM-33-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. 98-NM-33-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 all EMBRAER Model EMB-120 series airplanes. The DAC advises 
that it received one report of an in-flight incident involving roll 
control difficulties. Results of an inspection of the leading edge of 
the wing revealed that the top layer of the composite material just 
behind the upper edge of the de-ice boot had delaminated and was lifted 
up by the slipstream (airflow). Further investigation indicated that 
the replacement de-ice boot was installed improperly. The gaps between 
the upper edge of the de-ice boot and recess step were not filled with 
sealant at the time of installation. In addition, the delamination may 
have occurred during the original installation of the wing deicing 
system. This condition, if not corrected, could result in delamination 
of the wing and empennage leading edge, which could lead to reduced 
controllability of the airplane.

Explanation of Relevant Service Information

    EMBRAER has issued Alert Service Bulletin 120-51-A004, Revision 01, 
dated November 10, 1997, which describes procedures for a one-time 
visual inspection for delamination, erosion, and condition of fillet 
sealant and conductive edge sealer of the wing and empennage leading 
edge area behind the de-ice boots, and follow-on corrective actions. 
[The corrective actions include restoration of the conductive edge 
sealer (if erosion within specified limits is found), and application 
of a coat of conductive edge sealer over the anti-static paint at the 
recess step between the de-ice boot and the leading edge.] The DAC 
classified this alert service bulletin as mandatory and issued 
Brazilian airworthiness directive 97-09-07 (undated) 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 alert service bulletin described 
previously, except as discussed below.

Differences Between Proposed Rule and Alert Service Bulletin

    Operators should note that, although the alert service bulletin 
specifies that the manufacturer may be contacted for disposition of 
certain corrective actions, this proposal would require correction of 
those conditions to be accomplished in accordance with a method 
approved by the FAA.

Cost Impact

    The FAA estimates that 240 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 2 work 
hours per airplane to accomplish the proposed inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$28,800, or $120 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.

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 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 98-NM-33-
AD.

    Applicability: All Model EMB-120 series airplanes, 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

[[Page 14857]]

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 delamination of the wing and empennage leading edge 
due to improper installation of the wing de-ice boot, which could 
result in reduced controllability of the airplane, accomplish the 
following:
    (a) Within 75 flight hours or 120 days after the effective date 
of this AD, whichever occurs later: Perform a one-time visual 
inspection for delamination, erosion, and condition of fillet 
sealant and conductive edge sealer of the wing and empennage leading 
edge area behind the de-ice boots, in accordance with EMBRAER Alert 
Service Bulletin 120-51-A004, Revision 01, dated November 10, 1997. 
Except as provided by paragraph (b) of this AD, prior to further 
flight, accomplish follow-on corrective actions in accordance with 
the alert service bulletin.
    (b) If any discrepancy is found during accomplishment of 
paragraph (a) of this AD, and the alert service bulletin specifies 
to contact EMBRAER: Prior to further flight, repair the affected 
structure in accordance with a method approved by the Manager, 
Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane 
Directorate.
    (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 ACO. 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 97-09-07 (undated).

    Issued in Renton, Washington, on March 23, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8097 Filed 3-26-98; 8:45 am]
BILLING CODE 4910-13-P