June 13th-14th, 2002 International Systems Fire Protection Working Group CAA House - London, UK

1. Boeing 747SP CWT Inerting Efficiency William M CavageProject Manager - Fuel Tank Inerting FAA AAR-440, Fire Safety R&D Branch June 13th-14th, 2002International Systems Fire ProtectionWorking Group CAA House - London, UK

2. Vertical Mixing / Temperature Effects • Quiescent Full-Scale Testing has Indicated that Inerting of the 747SP in the Optimal Deposit Method Developed with the Plywood Model can be Problematic (No ACMs Operating) • Inerting Efficiency Different from Test to Test • Measured Strong “Vertical Effects” in one Full Length Bay • Bottom of Bay [O2] Lags Behind Top of Bay on Quiescent Tests • Complicated by the Fact that Sample System only Samples from Top • Preliminary Data Shows Effect is Not NEA Temperature Dependant but is Effected by the NEA Temperature AAR-422 Fire Safety R&D

3. 747SP Inerting Data with Different Vertical Mixing AAR-422 Fire Safety R&D

4. Inerting Efficiency • Due to Sample Lag Don’t have a Good Picture of Inerting in the Tank During Test • Sample Biased Due to Location of Sample Ports • Know Beginning Point (20.9) and End Point After Run ACMs • Want to Approximate the Progression of Tank Oxygen Concentration During the Testing • Use Generic Inerting Equation to Develop Efficiency Factor K • Solve for K and Redimensionalize to Get a Curve for Each Test Result • Have Multiple Tests with Different Mixing AAR-422 Fire Safety R&D

5. 747SP Calculated Inerting Curves with Different Vertical Mixing AAR-422 Fire Safety R&D

6. Summary • Although the Bay-to-Bay Distribution of NEA Was Predictable and Repeatable, Inerting Efficiency Varied from Test to Test due to Problems with Vertical Mixing • When Vertical Mixing is Stimulated, Inerting of a Compartmentalized Tank with a Localized Deposit is very Repeatable • Care will Need to be Taken During Deposit System Design to Ensure Good Vertical Mixing in Deposit Locations AAR-422 Fire Safety R&D