BRAZILIAN AIRWORTHINESS
DIRECTIVE
MINISTÉRIO DA AERONÁUTICA
EFFECTIVE DATE:
DEPARTAMENTO DE AVIAÇÃO CIVIL
AD Nr.:
13 Nov 98
92-08-04R1
The following Airworthiness Directive (AD), issued by the Departamento de Aviação Civil (DAC) in accordance with provisions of Chapter IV,
Title III of Código Brasileiro de Aeronáutica - Law NR. 7,565 dated 19 December 1986 - and Regulamento Brasileiro de Homologação
Aeronáutica (RBHA) 39, applies to all aircraft registered in the Registro Aeronáutico Brasileiro. No person may operate an aircraft to
which this AD applies, unless it has previously complied with the requirements established herein.
AD Nr. 92-08-04R1 - EMBRAER - Amendment 39-841.
APPLICABILITY:
This Airworthiness Directive is applicable to all EMBRAER EMB-120
“BRASILIA” aircraft models in operation.
CANCELLATION / REVISION:
This AD supersedes EAD Nr. T92-08-04 - Amdt 39-708, dated 06 August 1992,
and is being issued to revoke the inspection requirements established by that EAD for aircraft
which have incorporated the EMBRAER SB Nr. 120-76-018 or a production equivalent
modification.
REASON:
A propeller overspeed incident, affecting both engines of the EMB-120
simultaneously was reported at the time of the original issue of this AD, caused by an
inoperative secondary flight idle stop system, which have permitted the pilots to move the
power levers inadvertently below the primary flight idle stop in flight. The investigation
conducted at that time has revealed that the system circuit breakers of the affected aircraft were
tripped open due to the electrical characteristics of the installed solenoid, which may be altered
by the prolonged application of electrical current, as it may occur during maintenance.
Since this condition might occur in other airplanes of the same type and affect
flight safety, an immediate corrective action was required.
REQUIRED ACTION:
Daily inspection of the “FLT IDLE STOP SOL” circuit breakers condition and
periodic operational test of the secondary flight idle stop system.
COMPLIANCE:
Required as indicated below.
PART I - Aircraft of S/N 120004, 120006 thru 120067, and 120069 thru 120344, which have not
yet incorporated the EMBRAER SB Nr. 120-76-018, shall accomplish the inspection
requirements of paragraphs (a) and (b) below:
(a) Prior to the first flight of each day conduct a visual inspection of the “FLT IDLE
STOP SOL” circuit breakers CB 0582 and CB 0583, located inside the left lateral
console panel in the cockpit, to check that both are closed.
NOTE 1: This check may be performed by a flight crew member.
Form FDH-900-04A
CONTINUATION OF AD NR.:
92-08-04R1 -
AMENDMENT
39-841
PAGE NR..:
2/3
NOTE 2: The EMBRAER SB Nr. 120-076-0014 contains instructions for the
installation of an inspection window in the left lateral console, which
facilitates the accomplishment of this inspection.
(b) Perform an operational test of the secondary flight idle stop system as described
below at each 75 hours of time-in-service, or immediately after any maintenance
action where the power levers are moved with the airplane energized and on
jacks, or prior to further flight, if one or both circuit breakers CB 0582 and
CB 0583 are found not closed during the inspection required by paragraph (a):
(1) Move both power levers to the “MAX” position;
(2) Turn the aircraft POWER SELECT SWITCH on;
(3) Open both “AIR/GROUND SYSTEM” circuit breakers CB 0283 and
CB 0286 to simulate in-flight conditions with weight-off-wheels. Wait at
least 15 seconds, then move both power levers back towards the propeller
reverse position with the flight idle gate triggers raised. Check that the power
lever for each engine cannot be moved below the flight idle position, even
though the flight idle gate trigger on each power lever is raised;
(4) If either or both power levers can be moved below the flight idle position,
prior to further flight, restore the system to the configuration specified in
EMBRAER SB Nr. 120-076-0009, Rev. 4, or, alternatively, restore to the final
configuration specified in EMBRAER SB Nr. 120-76-018. After work
completion repeat this operational test;
NOTE: A power lever that can be moved below flight idle indicates that the
secondary flight idle stop system is inoperative.
(5) Move both power levers to the “MAX” position;
(6) Close both “AIR/GROUND SYSTEM” circuit breakers CB 0283 and
CB 0286 to simulate the airplane on the ground with weight-on-wheels. Wait
at least 15 seconds, then move both power levers back towards the propeller
reverse position with the flight idle triggers raised. Check that the power
levers for each engine can be moved below the flight idle position;
(7) If either or both power levers cannot be moved below the flight idle position,
prior to further flight, inspect the secondary flight idle stop system and the
flight idle gate system, and accomplish either paragraph (b)(7)(i) or (b)(7)(ii)
below, as applicable:
(i) If the secondary flight idle stop system is failing to disengage with
weight-on-wheels, restore the system to the configuration specified in
EMBRAER SB Nr. 120-076-0009, Rev. 4, or, alternatively, restore to the
final configuration specified in EMBRAER SB Nr. 120-76-018. After
work completion repeat this operational test;
(ii) If the flight idle gate system is failing to open even though the trigger is
raised, repair in accordance with the EMBRAER EMB-120 Maintenance
Manual;
(8) Turn the POWER SELECT SWITCH off. The operational test is complete.
Form FDH-900-04A
CONTINUATION OF AD NR.:
92-08-04R1 -
AMENDMENT
39-841
PAGE NR..:
3/3
PART II - Aircraft S/N 120068, 120345 and higher, as well as all other serial numbers which
have incorporated the EMBRAER SB Nr. 120-76-018, and have incorporated also the
associated AFM and MMEL related changes, are exempted from the special
inspection requirements of this AD.
The detailed instructions and procedures to accomplish this AD are described in
the EMBRAER Service Bulletins Nrs. 120-076-0009, Rev. 4, and 120-76-018, original issue, or
further revisions approved by the CTA.
Record compliance with this AD in the applicable maintenance log book.
CONTACT:
For additional technical information, contact:
Centro Técnico Aeroespacial - CTA
Instituto de Fomento e Coordenação Industrial - IFI
Divisão de Homologação Aeronáutica - FDH
Praça Mal. Eduardo Gomes, 50 - Vila das Acácias
Caixa Postal 6001
Fax: 55 (12) 341-4766
12231-970 - São José dos Campos - SP, BRAZIL.
For acquisition, contact:
Departamento de Aviação Civil - DAC
Seção Auxiliar do DAC (1GAB-4)
Av. Gal. Justo 160, 1º andar
Fax: 55 (21) 220-2227
20021-130 - Rio de Janeiro - RJ, BRAZIL.
APPROVAL:
LUIZ ALBERTO C. MUNARETTO - Ten.-Cel.-Av.
Chefe da Divisão de Homologação Aeronáutica
IFI/CTA
SILOMAR CAVALCANTE GODINHO - Cel.-Av.
Diretor do Instituto de Fomento e Coordenação Industrial
CTA
Note: Original in portuguese signed and will be available in the files of the Registro Geral
de Aeronavegabilidade (RGA/TE-1/STE) of the Departamento de Aviação Civil.
Form FDH-900-04A