[Federal Register Volume 63, Number 28 (Wednesday, February 11, 1998)]
[Rules and Regulations]
[Pages 6842-6844]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-2826]



[[Page 6842]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-231-AD; Amendment 39-10311; AD 98-03-19]
RIN 2120-AA64


Airworthiness Directives; Empresa Brasileira de Aeronautica, S.A. 
(EMBRAER), Model EMB-120 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain EMBRAER Model EMB-120 series airplanes, that 
requires deactivation of certain circuit breakers, and a revision to 
the Airplane Flight Manual (AFM) to provide operational procedures to 
prevent loss of electrical power following an engine flameout. This AD 
also requires modifications of the electrical system, which terminate 
the requirement for the AFM revision and allow reactivation of the 
circuit breakers. This amendment is prompted by the issuance of 
mandatory continued airworthiness information by a foreign civil 
airworthiness authority. The actions specified by this AD are intended 
to prevent generator overload conditions that could result in loss of 
electrical power and failure of certain flight and landing control 
systems, and to prevent power interruption to the attitude heading 
reference system (AHRS) that could result in the display of erroneous 
heading information.

DATES: Effective March 18, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 18, 1998.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at FAA, Small Airplane Directorate, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 
450, Atlanta, Georgia; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: John W. McGraw, Aerospace Engineer, 
Systems and Flight Test Branch, ACE-116A, FAA, Atlanta Aircraft 
Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 
450, Atlanta, Georgia 30349; telephone (770) 703-6098; fax (770) 703-
6097.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain EMBRAER Model EMB-120 
series airplanes was published in the Federal Register on November 28, 
1997 (62 FR 63288). That action proposed to require deactivation of 
certain circuit breakers, and a revision to the Airplane Flight Manual 
(AFM) to provide operational procedures to prevent loss of electrical 
power following an engine flameout. That action also proposed to 
require modifications of the electrical system, which would terminate 
the requirement for the AFM revision and allow reactivation of the 
circuit breakers.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 227 airplanes of U.S. registry will be 
affected by this AD.
    It will take approximately 1 work hour per airplane to accomplish 
the required AFM revisions, and that the average labor rate is $60 per 
work hour. Based on these figures, the cost impact of the AFM revisions 
required by this AD on U.S. operators is estimated to be $13,620, or 
$60 per airplane.
    It will take approximately 90 work hours per airplane to accomplish 
the required modifications at an average labor rate of $60 per work 
hour. Required parts will cost approximately $4,150 per airplane. Based 
on these figures, the cost impact of the modifications required by this 
AD on U.S. operators is estimated to be $2,167,850, or $9,550 per 
airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. However, the FAA has been advised 
that 43 U.S. registered airplanes are in compliance in accordance with 
the requirements of this AD. Therefore, the future economic cost impact 
of this rule on U.S. operators is now $11,040 for accomplishment of the 
AFM revisions, and $1,757,200 for accomplishment of the modifications.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.

[[Page 6843]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

98-03-19  Empresa Brasileira De Aeronautica, S.A. (Embraer): 
Amendment 39-10311. Docket 97-NM-231-AD.

    Applicability: Model EMB-120, EMB-120RT, and EMB-120ER series 
airplanes; up to and including serial number 120291; 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 generator overload conditions that could result in 
loss of electrical power and failure of certain flight and landing 
control systems, and to prevent power interruption to the attitude 
heading reference system (AHRS) that could result in the display of 
erroneous heading information, accomplish the following:
    (a) For airplanes not equipped with an auxiliary power unit 
(APU); except serial numbers 120004, 120006 through 120024 
inclusive, 120026 through 120030 inclusive, 120033 through 120035 
inclusive, 120037, and 120040; on which Part I, II, or III of 
EMBRAER Service Bulletin 120-24-0008, Change 03, dated August 19, 
1994, or Change 04, dated October 3, 1995, has not been 
accomplished: Within 3 days after the effective date of this AD, 
accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD.
    (1) Trip (pull open) circuit breakers (CB) 534 (auxiliary 
generator 2 bus control) and CB 535 (auxiliary generator 1 bus 
control) located in the right-hand direct current (DC) relay box and 
left-hand DC relay box, respectively.
    (2) Install circuit breaker collars to prevent the circuit 
breakers from closing.
    (3) Install, near CB 534 and CB 535, a placard or tag with the 
following wording: ``Do not close CB 534 or CB 535.''
    (b) For all airplanes: Within 30 days after the effective date 
of this AD, accomplish paragraphs (b)(1), (b)(2), and (b)(3) of this 
AD.
    (1) Revise the Abnormal Procedures section of the FAA-approved 
Airplane Flight Manual (AFM) to include the following. This may be 
accomplished by inserting a copy of this AD into the AFM.


``SECTION III--ABNORMAL PROCEDURES:                                                                             
    ENGINE FAILURE                                                                                              
                                                                                                                
    ONE ENGINE INOPERATIVE APPROACH AND LANDING                                                                 
        If auxiliary power unit (APU) is not available                                                          
            Electrical Load................................  REDUCE TO BELOW 400 AMPS                           
                                                                                                                
        At least the following systems should be turned off: windshield heating, propeller de-ice, gasper fans, 
        recirculation fans, logotype lights, and taxi lights..                                                  
                                                                                                                
    CAUTION                                                                                                     
                                                                                                                
      Should an unexpected electrical power loss occur during a rejected takeoff or landing run, remember:......
       --Emergency brake will be available......................................................................
       --Below 45 knots (KT), turn anti-skid off to recover one normal brake pair (inboard or outboard).........
                                                                                                                
    ELECTRICAL FAILURE                                                                                          
        SHORT CIRCUIT IN THE RELAY BOX DIRECT CURRENT (DC)                                                      
         BUS 1                                                                                                  
                                                                                                                
       --GEN 1 OFF BUS, BUS 1 OFF. EMERG BUS OFF, CENTRAL BUS OFF, BATT OFF BUS and inverter 2 INOP lights      
        illuminated on the electrical panel..                                                                   
                                                                                                                
       Note: In some cases, the CENTRAL BUS OFF light may not illuminate........................................
                                                                                                                
       --ELEC light illuminated on the multiple alarm panel.....................................................
       --CAUTION light flashing.................................................................................
                                                                                                                
       Caution: DO NOT TRY TO RESET THE ELECTRICAL SYSTEM. .....................................................
                                                                                                                
            Electrical Emergency Switch....................  EMERG                                              
            Altitude.......................................  AT OR BELOW 25,000 FT                              
                                                                                                                
        Airplane is limited to 25,000 ft since the left engine bleed is closed due to loss of the electrical    
        power..                                                                                                 
       The engines or APU airstart and electrical crossfeed are not possible....................................
       The equipment connected to the relay box DC BUS 1, DC BUS 1, radio master DC buses 1B and 1C are out.    
        Land as soon as practical..                                                                             
                                                                                                                
       Note:....................................................................................................
                                                                                                                
        For airplanes Pre-Mod SB 120-24-0008, the AHRS 1 and the equipment connected to the radio master
        DC BUS 1A are out too..                                                                                 
        For airplanes Post-Mod SB 120-33-0033 or S/N 120.273 and on:....................................
         --The emergency lights will be automatically turned on when the electrical system is in emergency      
          operating mode..                                                                                      
         --The emergency lights must be turned off, in order to save the emergency light batteries..............
         --The emergency lights must be turned on during approach or when necessary.''..........................
                                                                                                                

    (2) Revise the Normal Procedures section of the FAA-approved AFM 
to include the following. This may be accomplished by inserting a 
copy of this AD into the AFM.


``SECTION IV--NORMAL PROCEDURES:                                                                                
    BEFORE TAKEOFF                                                                                              
                                                                                                                
    If APU is available                                                                                         
        APU Generator......................................  ON                                                 
                                                                                                                
        Takeoff must be carried out with APU generator connected to the central DC bus, thus providing another  
        source to avoid overload should one engine flame out..                                                  
                                                                                                                
    If APU is not available                                                                                     
        Electrical Load....................................  REDUCE TO BELOW 400 AMPS                           
                                                                                                                
 
[[Page 6844]]

                                                                                                                
       At least the following systems should be turned off: windshield heating, propeller de-ice, gasper fans,  
        recirculation fans, logotype lights, and taxi lights..                                                  
                                                                                                                
    AFTER TAKEOFF                                                                                               
        If APU is available                                                                                     
                                                                                                                
        APU................................................  AS REQUIRED                                        
        If APU is not available                                                                                 
                                                                                                                
        Electrical load....................................  RESTORE                                            
        Windshield heating.................................  AS REQUIRED                                        
        Emergency lights switch............................  OFF, then ARM                                      
    APPROACH                                                                                                    
        If APU is available                                                                                     
                                                                                                                
        APU Generator......................................  ON                                                 
                                                                                                                
        Approach and landing must be carried out with APU generator connected to the central DC bus.............
                                                                                                                
    BEFORE LANDING                                                                                              
        If APU is not available                                                                                 
                                                                                                                
        Electrical Load....................................  REDUCE TO BELOW 400 AMPS                           
                                                                                                                
        At least the following systems should be turned off: windshield heating, propeller de-ice, gasper fans, 
        recirculation fans, logotype lights, and taxi lights. .                                                 
       CAUTION: Do not set electrical emergency switch to emergency position during approach or landing.''......
                                                                                                                

    (3) Revise the Limitations section (Section II) of the FAA-
approved AFM to include the following. This may be accomplished by 
inserting a copy of this AD into the AFM.
    ``Both starter/generators must operate normally prior to flight. 
The APU generator must operate normally prior to flight in known or 
forecast icing conditions. [Note: This supersedes any relief 
provided by the Master Minimum Equipment List (MMEL).]''
    (c) Within 12 months after the effective date of this AD, 
accomplish paragraphs (c)(1) and (c)(2) of this AD, as applicable.
    (1) For all airplanes except serial numbers 120004, 120006 
through 120024 inclusive, 120026 through 120030 inclusive, 120033 
through 120035 inclusive, 120037, and 120040; on which Part I, II, 
or III of EMBRAER Service Bulletin 120-24-0008, Change 03, dated 
August 19, 1994, or Change 04, dated October 3, 1995; has not been 
accomplished: Modify the electrical system in accordance with Part 
IV of EMBRAER Service Bulletin 120-24-0008, Change 04, dated October 
3, 1995. After this modification is accomplished, the modification 
required by paragraph (a) of this AD may be removed and the affected 
circuit breakers reactivated.
    (2) For all airplanes: Modify the electrical system in 
accordance with EMBRAER Service Bulletin 120-24-0051, Change 04, 
dated March 8, 1995. After this modification is accomplished, the 
AFM revisions required by paragraph (b) of this AD may be removed 
from the AFM.
    (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.

    (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.
    (f) The actions shall be done in accordance with the following 
EMBRAER service bulletins, which contain the specified effective 
pages:

----------------------------------------------------------------------------------------------------------------
                                                                               Revision                         
Service bulletin referenced and                   Page No.                   level shown    Date shown on page  
              date                                                             on page                          
----------------------------------------------------------------------------------------------------------------
120-24-0008, Change 04, October  1-4.......................................           04  Oct. 3, 1995.         
 3, 1995.                        5-64......................................           03  Aug. 19, 1994.        
120-24-0051, Change 04, March    1-4, 41-46, 59, 60, 89-92.................           04  Mar. 8, 1995.         
 8, 1995.                        5-40, 47-58, 61-88, 93-103................           03  Nov. 3, 1994.         
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Empresa Brasileira de Aeronautica, 
S.A. (EMBRAER), P.O. Box 343--CEP 12.225, Sao Jose dos Campos--SP, 
Brazil. Copies may be inspected 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; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

    Note 3: The subject of this AD is addressed in Brazilian 
airworthiness directives (DAE) 93-24-01, dated December 31, 1993; 
94-03-01R1, dated December 10, 1994, and 93-12-01R1, dated December 
12, 1994.

    (g) This amendment becomes effective on March 18, 1998.

    Issued in Renton, Washington, on January 30, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-2826 Filed 2-10-98; 8:45 am]
BILLING CODE 4910-13-U