[Federal Register Volume 65, Number 74 (Monday, April 17, 2000)]
[Proposed Rules]
[Pages 20388-20390]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-9556]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-356-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 revising the Airplane 
Flight Manual (AFM), and either installing hydraulic tube assemblies 
incorporating a check valve, or visually inspecting the check valve if 
already installed and corrective action, if necessary. 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 the landing gear doors from 
becoming blocked from opening during application of emergency 
procedures in the event of a loss of hydraulics.

DATES: Comments must be received by May 17, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-356-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: Robert Capezutto, Aerospace Engineer, 
Systems and Flight Test Branch, ACE-

[[Page 20389]]

116A, FAA, Small Airplane Directorate, Atlanta Aircraft Certification 
Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, 
Georgia 30349; 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 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 99-NM-356-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. 99-NM-356-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 EMB-120 series airplanes. The DAC advises 
that, in the event of the loss of the green hydraulic system pressure, 
if the present Airplane Flight Manual (AFM) ``Free-Fall'' operational 
procedure is not followed, there is a possibility that the landing gear 
doors may not open. Investigation revealed that blockage of the doors 
may occur due to the energizing of the landing gear door selector valve 
in the absence of hydraulic fluid. (The spool valve may not shift 
completely and may result in trapped fluid in the door's closure line.) 
This condition, if not corrected, could result in the landing gear 
doors becoming blocked from opening during application of emergency 
procedures in the event of a loss of hydraulics.

FAA's Determination

    In light of this information, the FAA finds that certain cautionary 
statements should be included in the FAA-approved AFM to ensure that 
correct procedures are followed in the event of a loss of hydraulics. 
The FAA has determined that the procedures currently may not be defined 
adequately in the AFM for these airplanes.

Explanation of Relevant Service Information

    Empresa Brasileira de Aeronautica S.A. (EMBRAER) has issued Service 
Bulletin 120-32-0077, Change 02, dated December 23, 1997, which 
describes procedures for installation of hydraulic tube assemblies 
incorporating a check valve. For airplanes already equipped with those 
check valves, the service bulletin describes procedures for a visual 
inspection to detect the check valve flow direction, and reorientation 
of the valve, if installed incorrectly. The DAC classified this service 
bulletin as mandatory and issued Brazilian airworthiness directive 97-
05-03R2, dated March 16, 1998, in order to assure the continued 
airworthiness of these airplanes in Brazil. The installation of 
hydraulic tube assemblies incorporating a check valve is intended to 
modify the hydraulic system to make the landing gear ``Free-Fall'' 
system more tolerant to operational variations from AFM procedures. The 
Brazilian AD also mandates incorporation of an AFM revision of abnormal 
landing gear extension procedures.

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 incorporation of a 
revision to the ``Emergency Procedures'' and ``Abnormal Procedures'' 
sections of the FAA-approved AFM. This revision includes cautionary 
statements to ensure that correct procedures are followed in the event 
of a loss of hydraulics. The AD would also require accomplishment of 
the actions specified in the service bulletin described previously.

Differences Between Proposed Rule and Brazilian Airworthiness 
Directive

    The proposed AD differs from the parallel Brazilian airworthiness 
directive. This proposed AD would require the check valve installation 
within 2,000 flight hours after the effective date of the AD, whereas 
the original version of the Brazilian airworthiness directive mandated 
the installation within 400 hours after the effective date of that AD. 
The 2,000-flight-hour interval generally corresponds to a ``C-check'' 
maintenance period for the EMBRAER EMB-120. The FAA finds that a 2,000-
flight-hour compliance time provides an adequate level of safety, and 
will allow operators to accomplish the installation at the next ``C-
check.''
    The Brazilian airworthiness directive mandates incorporation of a 
specific revision level for each of five different AFM's. Of these 
five, only AFM 120/794 is applicable to U.S.-registered airplanes. 
Thus, the proposed AD would mandate incorporation of Revision 45 to AFM 
120/794.

Cost Impact

    The FAA estimates that 213 airplanes of U.S. registry would be 
affected by this proposed AD.
    The FAA estimates that it would take approximately 1 work hour per 
airplane to incorporate the applicable AFM revision, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the AFM revision proposed by this AD on U.S. operators 
is estimated to be $12,780, or $60 per airplane.
    The FAA estimates that it would take approximately 1 work hour per 
airplane to perform the visual inspection of the check valve, and that 
the average labor rate is $60 per work hour. Based on these figures, 
the cost impact of the inspection proposed by this AD on U.S.

[[Page 20390]]

operators is estimated to be $60 per airplane.
    The FAA estimates that it would take approximately 2 work hours per 
airplane to install the hydraulic tube assemblies incorporating a check 
valve, and that the average labor rate is $60 per work hour. Required 
parts would cost approximately $2,021 per airplane. Based on these 
figures, the cost impact of the installation proposed by this AD on 
U.S. operators is estimated to be $2,141 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 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 99-NM-356-
AD.

    Applicability: Model EMB-120 series airplanes as listed in 
EMBRAER Service Bulletin 120-32-0077, Change 02, dated December 23, 
1997; 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 (d) 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 the landing gear doors from becoming blocked from 
opening during application of emergency procedures in the event of a 
loss of hydraulics, accomplish the following:
    (a) Within 10 flight hours after the effective date of this AD, 
revise the ``Emergency Procedures'' and ``Abnormal Procedures'' 
sections of the FAA-approved Airplane Flight Manual (AFM) by 
inserting into the AFM a copy of EMB-120 AFM 120/794, Revision 45, 
dated October 14, 1996.
    (b) For airplanes on which the check valve has been installed in 
accordance with EMBRAER Service Bulletin 120-32-0077, dated February 
7, 1997: Within 100 hours after the effective date of this AD, 
conduct a visual inspection to detect the check valve flow direction 
in accordance with Service Bulletin 120-32-0077, Change 02, dated 
December 23, 1997. If the check valve is installed incorrectly, 
prior to further flight, reinstall the check valve in the proper 
position in accordance with Change 02 of the service bulletin.
    (c) For airplanes on which the check valve has not been 
installed in accordance with EMBRAER Service Bulletin 120-32-0077, 
dated February 7, 1997; or Change 01, dated September 25, 1997; or 
Change 02, dated December 23, 1997: Within 2,000 flight hours after 
the effective date of this AD, install hydraulic tube assemblies 
incorporating a check valve in accordance with Service Bulletin 120-
32-0077, Change 01, dated September 25, 1997; or Change 02, dated 
December 23, 1997.

Alternative Methods of Compliance

    (d) 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.

Special Flight Permits

    (e) 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 97-05-03R2, dated March 16, 1998.


    Issued in Renton, Washington, on April 11, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-9556 Filed 4-14-00; 8:45 am]
BILLING CODE 4910-13-P