Appendix 1 to ETSO-C55a A1 -- Fuel and Oil Quantity Instruments

• ED Decision 2022/018/R found in: CS-ETSO Amdt 17 - European Technical Standard Orders (Oct 2026)

###### Appendix 1 to ETSO-C55a A1 — Fuel and Oil Quantity Instruments *ED Decision 2022/018/R* This Appendix prescribes the minimum performance standard for fuel and oil quantity instruments, as modified by EASA. The applicable standard is: — SAE AS405C ‘Fuel and Oil Quantity Instruments’, dated July 2001; or — SAE AS405D ‘Fuel and Oil Quantity Instruments’, dated August 2012. Conformance with the following paragraphs of SAE AS405C or AS405D is not required: 3.1, 3.1.1, 3.1.2, 3.2 and 4.2.1. A.1. ADDITIONS TO SAE AS405C or AS405D, PARAGRAPH 5 Paragraph 5.7, Instrument Setup a. Before starting tests, set up the instrument as follows: (1) place the sensor component in a simulated fuel or oil tank, and the indicator and other components in a convenient location; and (2) connect all the components using the same means as is required when the instrument is in service. b. You may choose to test individual components. When testing components individually, provide proper inputs or outputs for the components being tested. Paragraph 5.8, Accuracy Tolerances All accuracy tolerances are for the complete system. Before testing components individually, connect the components per the manufacturer’s instructions. The complete system must meet the tolerances of Table 1 (see SAE AS8029, ‘Minimum Performance Standard for Fuel and Oil Quantity Indicating System Components’, dated June 1983): ***Table 1 — Accuracy tolerances for the complete system*** <table bgcolor="#d9d9d9" cellpadding="7" cellspacing="0"> <col/> <col/> <tr valign="top"> <td bgcolor="#808080"><p align="center"> <b>Class</b></p> </td> <td bgcolor="#808080"><p align="center"> <b>Accuracy tolerance</b></p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p align="center"> <b>1</b></p> </td> <td bgcolor="#d9d9d9"><p align="center"> ± 0.75 % full scale</p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p align="center"> <b>2</b></p> </td> <td bgcolor="#d9d9d9"><p align="center"> ± 2 % of full scale</p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p align="center"> <b>3</b></p> </td> <td bgcolor="#d9d9d9"><p align="center"> ± 3 % of full scale</p> </td> </tr> </table> Paragraph 5.9, Ambient Room Conditions At ambient room conditions, test the instrument for scale errors, hysteresis errors, friction errors, and position errors. The resulting total error must not exceed the values in the applicable listing in Table 1 of this Appendix. Paragraph 5.10, Applicable Environmental Conditions Test the instrument under the applicable environmental conditions. The resulting total error must not exceed the values in the applicable listing in Table 1 of this Appendix. A.2. MODIFICATIONS TO SAE AS405C or AS405D, PARAGRAPH 6 <table bgcolor="#d9d9d9" cellpadding="7" cellspacing="0"> <col/> <col/> <tr valign="top"> <td bgcolor="#808080"><p> <b>Replace all the wording in:</b></p> </td> <td bgcolor="#808080"><p> <b>With:</b></p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p> <b>Paragraph 6.1, Scale Error</b></p> </td> <td bgcolor="#d9d9d9"><p> Adjust the tank unit and all the components before the test. You cannot adjust anything during the test. Immerse the tank unit, and compensators when used, in the test fluid. Calculate the percentage of errors by comparing the readings taken from the design calibration of the system or component you are testing.</p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p> <b>Paragraph 6.2, Friction</b></p> </td> <td bgcolor="#d9d9d9"><p> Test all the components with moving parts for friction errors at several points. Test the components by applying the needed inputs to bring the output to a desired test point. Hold the input constant while taking the two output readings. Take the first reading before vibrating the indicator. Take the second reading after vibrating the indicator.</p> </td> </tr> <tr valign="top"> <td bgcolor="#808080"><p> <b>Paragraph 6.4, Position Error</b></p> </td> <td bgcolor="#d9d9d9"><p> To obtain a reading near mid-scale, the fluid tank should be about half-full, or have the equivalent electrical input. Hold each component (except the tank unit) in several different positions and record any change in output. Test the instrument for position errors in several positions.</p> </td> </tr> </table> A.3. ADDITIONS TO SAE AS405C or AS405D, PARAGRAPH 6. Paragraph 6.8, Hysteresis Error Test the instrument for hysteresis at several points. Increase the test fluid level or apply equal inputs to each selected test point and hold them while taking a reading. Paragraph 6.9, Speed of Response At ambient room conditions, the indicator must register from empty to full or vice versa in less than 30 seconds, but more than 5 seconds. When testing at any environmental extremes, the speed of response must not exceed 3 times the time measured at ambient room conditions. A.4. MODIFICATIONS TO SAE AS405C or AS405D, PARAGRAPH 7 *Replace:* ‘As many instruments as deemed necessary to demonstrate that all instruments will comply with the requirements of this section shall be tested in accordance with the manufacturer’s recommendation.’ *with the following:* ‘Performance tests: The following tests, in addition to any others deemed necessary by the manufacturer, shall be the basis for determining compliance with the performance requirements of this standard.’ A.5. ADDITIONS TO SAE AS405C or AS405D, PARAGRAPH 7 Add the following new paragraphs: Paragraph 7.7, Operational Shock Tests Use the test requirements in Section 7 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.8, Explosion Proof Test Use the test requirements in Section 9 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.9, Power Input Test Use the test requirements in Section 16 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.10, Voltage Spike Test Use the test requirements in Section 17 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.11, Audio Frequency Conducted Susceptibility Test Use the test requirements in Section 18 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.12, Induced Signal Susceptibility Test Use the test requirements in Section 19 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.13, Radio Frequency Susceptibility Test Use the test requirements in Section 20 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.14, Emission of Radio Frequency Energy Test Use the test requirements in Section 21 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.15, Lightning Induced Transient Susceptibility Test Use the test requirements in Section 22 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.16, Lightning Direct Effects Test Use the test requirements in Section 23 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.17, Electrostatic Discharge Test Use the test requirements in Section 25 of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1. Paragraph 7.18, Flammability Test All the materials used must be self-extinguishing when tested in accordance with the applicable requirements of RTCA/DO‑160E or later version as defined in CS‑ETSO, Subpart A, paragraph 2.1, Section 26, Category C, Flammability Test. This requirement does not apply to small parts (where the greatest equipment dimension is less than 50 mm, such as knobs, fasteners, seals, grommets and small electrical parts) that do not contribute significantly to fire propagation. [Amdt ETSO/17]