IASFPWG – Atlantic City, NJ Limiting Oxygen Concentration (LOC) Work Update International Aircraft Systems Fire Protection Working Group Atlantic City, NJ November 5 - 6, 2003 Steve Summer Project Engineer Federal Aviation Administration Fire Safety Branch, AAR-440

IASFPWG – Atlantic City, NJ LOC Testing – Work Update  Technical Note consisting of all data except 400 cycle short tests published and placed on website (AR-02/79)  400 cycle short spark energy has been measured and testing has been completed  Final report currently being put together

IASFPWG – Atlantic City, NJ Facilities – Pressure Chamber

IASFPWG – Atlantic City, NJ Facilities – Pressure Chamber  353 ft 3 pressure vessel Working pressure of 650 psi. Attached vacuum pump used to evacuate chamber to reduced pressures seen at altitude. Not capable of simulating temperatures seen at altitude.

IASFPWG – Atlantic City, NJ Facilities - LOC Test Article  9 ft 3 simulated fuel tank placed inside of vessel equipped with: Bottom surface heaters. 12 thermocouples. 2 piezoresistive pressure transducers mounted behind sintered porous metal discs. Interchangeable pressure relief mechanism.  ¼-in. aluminum plate.  Foil diaphragm. Spark gap.  2 tungsten electrodes with controllable gap alignment and spacing

IASFPWG – Atlantic City, NJ Apparatus – LOC Testing

IASFPWG – Atlantic City, NJ Apparatus – LOC Testing

IASFPWG – Atlantic City, NJ Ullage Vapor Sampling

IASFPWG – Atlantic City, NJ LOC Testing Apparatus  Ignition Sources 10 kV Oil burner transformer operating at ~30 mA provided both long (~1 second) and short (~0.1 second) arcs J-57 Engine spark igniter provided a very short (~175  second) spark 3" x 6" x 1" metal block heated by two cartridge heaters to temperature in excess of 1400°F 400 cycle, 120 V hard short to ground provided high energy/current, short duration spark  Energy Measurements Voltage and current traces were taken using a HV and current probe at the spark gap connected to oscilloscope

IASFPWG – Atlantic City, NJ Test Program  JP-8 LOC Tests Mass Loading ~ 4.5 kg/m 3 Ambient pressure corresponding to altitudes of 0, 10, 20, 30 and 38 kft Ullage oxygen concentrations ranging from 21% to below the determined LOC Tests conducted with two different pressure relief mechanisms  ¼-in. aluminum plate – Ignition = movement of plate  Foil diaphragm –Ignition = rupture of foil

IASFPWG – Atlantic City, NJ Test Program (cont.)  Tests conducted initially at all altitudes with long duration oil burner transformer arc (~0.5 J, 1 s)  Subsequent tests conducted with various ignition sources at sea level in effort to determine any variation of LOC with ignition source Short duration oil burner transformer arc (~0.08 J, 0.1 s) J-57 Engine igniter spark (~0.5 J, 175  s) Hot surface vapor ignition (HSVI) 400 cycle, 120 V hard short to ground

IASFPWG – Atlantic City, NJ

IASFPWG – Atlantic City, NJ 400 Cycle Hard Short Tests

IASFPWG – Atlantic City, NJ Spark Energy Measurements Energy ~ 2.2 J Duration ~.006 s Energy ~ 2.8 J Duration ~.01 s Energy ~ 1.75 J Duration ~.01 s

IASFPWG – Atlantic City, NJ 400 Cycle Short Test Results

IASFPWG – Atlantic City, NJ Summary  ~2 J spark from 400 cycle short did not cause a change in the LOC at sea level  Of all ignition sources used (oil burner arc, engine ignitor spark, hot surface, 400 cycle short), none have caused an ignition with ullage above 12% O 2  Testing is complete and final report will be published and available on website ASAP