Training Workshop «DO160/ED14» - Jessica France DO160/ED14 Issue F to G Edouard ZUNDEL Systems Qualification Engineer for Mechanical and Climatic aspects 1
Overview - Temperature &Altitude Procedure clarification Precision on temperature for which the equipment has to be power on after ground survival test if short time operating temperatures and operating temperatures are the same. Power should be applied at the operating low temperature after the unpowered low temperature soak 2
Overview - Temperature variation Procedure clarification Provide guidance on combined temperature test procedure in ordernottogobacktoambientintheintermediatephase. Risk limitation Limit the risk of condensation or Icing during temperature variation test Noteadded: This test is not intended to verify the behavior of the equipment in wet or icing conditions. In conducting this test, the test chamber may incorporate the capability of controlling or altering humidity to the extent that condensation is minimized or does not occur. 3
Overview - Humidity terminology Proper use of terminology requisite for ph (POWER CONCENTRATION OF THE HYDROGEN ). The word HYDROXIDE is removed Overview - Operational Shocks and Crash Safety Test deviation Note added to allow toperform test in non operating mode if stated in equipment specification. Objective : allow test deviation for rotating equipment such as an electrical generator 4
Overview - Explosive atmosphere Clarification Environment definition (more guidance to be in accordance with FAR 863 than test procedure) defined in section 9 user guide Clarification Test alternative Categories definition improvement for clarification and consistency. Proposed definition is easily lined with test methods. Verification of explosive mixture should to be done with thermocouple or pressure transducer If the case volume is greater than 1/50 of chamber volume an alternative to purging entire chamber would be to prove explosive mixture is correct after each case explosion 5
Overview - Explosive atmosphere Equipment categories and test methods Eqt Category A Method Containment test 9.6.1 or hermitically sealed case. Surface temperature test 9.6.3. E Non ignition test of 9.6.2 H (non spark producing equipment or hermitically sealed) Surface temperature test 9.6.3 6
Overview - Explosive atmosphere Installation of Equipment in the Aircraft A/C Zone Method definition Failure conditions I II III IV aircraft area in which uncovered flammable fluids or vapors exist, or can exist, either continuously or intermittently. aircraft area in which flammable mixtures can be expected to occur only as a result of a single fault-causing spillage or leakage. aircraft area in which flammable mixtures cannot be expected to occur as a result of a single fault-causing spillage or leakage. Fire zone or aircraft area in which flammable mixtures cannot be expected to occur as a result of a double fault-causing spillage or leakage. Double failure conditions need to be considered Only equipment single failure shall be considered. Only nominal operation need to be considered No requirement Nominal operational tests as defined in ED14/DO160 are not sufficient for installation in Zone I or II where failure modes need to be considered with testing or analysis. 7
Overview - Fluids susceptibility Clarification Improvement Class of Contaminating Fluid Solvents and Cleaning Fluids Fire extinguishants As there is some interpretation in the industry that all fluids are required to be tested to claim category F, note added to clarify category F compliance: note added: Testing of all 25 fluids or all 7 general classes of contaminated fluids is not required to claim category F. It is required to specify fluids used, test method and temperature of exposure in the test procedure and the Environmental Qualification Form. Two fluids added to fluids list Alignment with MIL STD 810G Test Fluid Isopropyl Alcohol Denatured Alcohol Cleaning compound for aircraft surfaces Trans-1-2Dichloroethylene (replacement for 1,1,1-Trichloroethene) Protein Fluoroprotein Aqueous Film Forming Foam (ATTF) Fluid Temperature Degrees C 50 1/ 23 1/ 23 23 23 23 23 8
Overview - Fluids susceptibility ED14-F ED14-G Spray 8h Test Procedure improvement Spray 24h Drying time 16h Spray 8h Change the spray test to the similar method that is used in MIL- STD-810G. Spray 8 hours followed by 16 hours of drying, repeated 3 times Change requirement of operation of Unit at end of each fluid drying period from 2 hours to 30 minutes minimum or until stabilized Background shows that reaction to material from fluid application is generally noticed within the first 24 hours and does not get worse or change as a result of 7 days of drying. Drying time 16h Spray Operate EUT during 10 minutes 8h Drying time 16h Drying time 160h Operate EUT during 2 Hours (30 minutes in issue G) Time saving : more than 4 days per fluid 9
Overview Sand & Dust Test procedure Improvement Sand composition (particle size distribution) simplification to ease test preparation en reduce costs. Alignment with MIL-STD-810F and G (previous issue was derived from MIL-STD-810E). ED14 -F ED14 -G 1% +/-0.5% shall be retained by a 20 mesh screen, i.e., diameter 0.85 mm 2.7% +/-0.5% shall be retained by a 30 mesh screen, i.e., diameter 0.59 mm 17.5% +/-2% shall be retained by a 40 mesh screen, i.e., diameter 0.42 mm 53.5% +/-2% shall be retained by a 50 mesh screen, i.e., diameter 0.30 mm 82.1% +/-2% shall be retained by a 70 mesh screen, i.e., diameter 0.21 mm 94.8% +/-2% shall be retained by a 100 mesh screen, i.e., diameter 0.15 mm 5.2% +/-2% shall be retained by a 100 mesh screen 90 ±5 percent by weight smaller than 600 μmand larger than or equal to 150 μm, at least 5 percent by weight 600 μm and larger. 10
Overview Salt Fog ED14-F ED14-G Test Procedure improvement ATP Exposition 48h Test procedure modification taken into account experience: alternating 24-hour periods of salt fog exposure and drying conditions for a minimum of four 24-hour periods (two wet and two dry), provides more realistic exposure and a higher damage potential than does continuous exposure to a salt atmosphere. Exposition 96h Drying time 24h Drying time 24h Exposition 48h Drying time 24h 11
For more information http://www.fire.tc.faa.gov/materials.asp 12
Background New advisory circular (AC21-16F) identifies RTCA Doc. No. (RTCA/DO)-160F as an acceptable means of environmental qualifications for showing compliance with airworthiness requirements. The AC excludes Section 26, Fire and Flammability Main reasons for this exclusion : - the sec. 26 flammability was based on UL 94 test procedures and not as stringent as Part 25 Appendix F procedures. The FAA Technical Center was requested to work with members of the EUROCAE/RTCA to develop flammability test criteria and procedures for electronic enclosures. 13
Background (continued) The purpose of this group was to draft a new Section 26 for inclusion into RTCA DO-160 document. The group focused on testing specified in FAR 25.853, Appendix F: - Vertical Bunsen burner test - Horizontal Bunsen burner test - The 60 degree wire test - The 45 degree test Once Revision G is finalized, the WG will working on alternate test methods (i.e., a box test ) through the working group. 14
Section 26 - Applicability Flammability and fire tests apply to equipment installed on fixed wing propeller driven aircraft, fixed-wing turbojet aircraft, turbofan aircraft, prop fan aircraft, and helicopters. These tests are applicable for equipment: - Mounted in pressurized zones - Mounted in fire zones - Mounted in non-pressurized, non fire zones 15