Airworthiness Directive · Amendment 39-16659 · Fuel
Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120, -120ER, -120FC, -120QC, and -120RT Airplanes
This AD applies to all Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120, -120ER, -120FC, -120QC, and -120RT airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 600 flight hours or 180 days after the effective date of this AD, whichever occurs first, with at least 400 kg (882 lb) of fuel in each tank, determine the real fuel quantity in each tank using the dripless measuring sticks, in accordance with Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia AMM, MM-120/1459, Revision 27, dated September 28, 2010; or in accordance with Task 28-25, Operational Check Fuel Quantity Indicating System (Measuring Sticks), specified in Section 3, Systems and Powerplant Inspection Requirements, in EMBRAER EMB120 Models Maintenance Review Board Report (MRBR), MRB-HI-200, Revision 26, dated January 5, 2010. Before further flight, compare the results of the fuel quantity measurement with the fuel master indicator and repeater indicator readings for each tank and do the applicable action in paragraph (g)(1), (g)(2), or (g)(3) of this AD.
(1) If the difference of the two measurements is greater than 60 kg (132 lb) on both tanks, before further flight do all applicable corrective actions including correcting the fuel quantity indication system (FQIS), in accordance with Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia AMM, MM-120/1459, Revision 27, dated September 28, 2010.
(2) If the difference of the two measurements is greater than 60 kg (132 lb) on only one tank, and the conditions in paragraphs (g)(2)(i), (g)(2)(ii), and (g)(2)(iii) of this AD are met, do all applicable corrective actions including correcting the FQIS, in accordance with Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia AMM, MM-120/1459, Revision 27, dated September 28, 2010, within 10 days after determining the real fuel quantity as specified in paragraph (g) of this AD.
(i) Before further flight after each refueling, the actions required in paragraph (g) of this AD are done;
(ii) Both fuel flow indicators are operating properly; and
(iii) The fuel used or fuel remaining function of the totalizer is operating properly.
(3) If the difference of the two measurements is greater than 60 kg (132 lb) on only one tank, and any condition in paragraph (g)(2)(i), (g)(2)(ii), or (g)(2)(iii) of this AD is not met, before further flight do all applicable corrective actions including correcting the FQIS, in accordance with Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia AMM, MM-120/1459, Revision 27, dated September 28, 2010.
(h) Repeat the actions required in paragraph (g) of this AD thereafter at intervals not to exceed 600 flight hours or 180 days, whichever occurs first.
(i) Inspections accomplished before the effective date of this AD according to Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, the EMBRAER EMB120 Brasilia Aircraft Maintenance Manual, MM-120/1459, Revision 24, dated March 30, 2009; Revision 25, dated September 28, 2009; and Revision 26, dated March 29, 2010; are considered acceptable for compliance with the corresponding actions specified in this AD.
Note 1: This AD differs from the MCAI and/or service information as follows: This AD requires doing all applicable corrective actions in accordance with Subjects 28-41-00, Fuel Quantity Indicating System, and 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia AMM, MM-120/1459, Revision 27, dated September 28, 2010. Corrective actions include replacing the measuring stick and its relevant magnetic float, replacing the master fuel quantity indicator, and replacing the repeater indicator, as applicable; inspecting defective tank units for contamination, corrosion and integrity of components, and repairing or replacing as necessary; inspecting system wiring from the connector at the wing root to the master indicator for condition and continuity; and correcting the fuel quantity indication system; as applicable. The MCAI does not provide a corrective action and only requires a repetitive functional check of the FQIS in accordance with Subject 28-42-00, Fuel Quantity Measuring Sticks Assembly—Description and Operation, of Chapter 28, Fuel, of the EMBRAER EMB120 Brasilia Aircraft Maintenance Manual, Revision 24, dated March 30, 2009. This difference has been coordinated with Agência Nacional de Aviação Civil (ANAC).
