July 17-18, 2001 International Aircraft Systems Fire Protection Working Group Wilson, NC

1. Scale Model InertingTesting with 1/4 Scale Boeing 747 SP Fuel Tank July 17-18, 2001International Aircraft Systems FireProtection Working GroupWilson, NC AAR-422 Fire Safety R&D

2. Background • Inconsistent Comparisons of Test Data Created Questions of NEA Required to Inert an Aircraft Center Wing Tank • Focus of the Testing is to Better Determine the Best Method to Inert a Compartmentalized Fuel Tank • Study Equal NEA Distribution and Localized NEA Deposit • Study Cross-Vented and Single Vent Configurations • Develop Methods to Make Fair Comparisons. AAR-422 Fire Safety R&D

3. Test Article • Quarter Scale Model of Boeing 747 SP CWT was Built from Plywood By Scaling Drawings from Shepherd Report • 24% length Scale (1.2% Volume) • Scaled all Bay-Bay Penetrations • “Variable Manifold” Allows for Depositing NEA in Any and All Bays of the Tank at Different Rates to Support Inerting Times as Low as 10 Minutes • Oxygen Sensor in Each Bay and in One Vent Channel AAR-422 Fire Safety R&D

4. Scale Model Bay Convention Dry Bay 1 2 3 4 5 6 AAR-422 Fire Safety R&D

5. Preliminary Balanced Data • Inerted Tank Several Times with NEA 95% and NEA 98% with the Goal of Balancing the Flow into Inert Each Bay “Equally” for Standard Cross-Venting Configuration • Acquired Data with a Stop Watch (1 reading per minute) • Developed a Volumetric Average to Make Comparisons with Other Inerting Runs • Results As Expected and Consistent with Previous Testing but New Numbers Point Toward a VTE of 1.6 for 95% NEA • VTE Very Sensitive to O2 Concentration at 8% for 95% NEA AAR-422 Fire Safety R&D

6. Preliminary Balanced Inerting Data AAR-422 Fire Safety R&D

7. Preliminary Balanced Weighted Average Data AAR-422 Fire Safety R&D

8. Preliminary Unbalanced Data • Inerted Tank Several Times with NEA 95% with the Goal of Minimizing the Volume Required to Inert the Tank with Standard Cross-Venting Configuration • Acquired Data with a Stop Watch (1 reading per minute) • Used the Volumetric Average Developed to Make Fair Comparisons with Other Inerting Runs • Results Illustrated Very Little Improvement in VTE Required, but Allowed for Simpler Manifold Designs • Smart Design as Good or Better then Well Balanced Manifold AAR-422 Fire Safety R&D

9. Preliminary Unbalanced Inerting Data AAR-422 Fire Safety R&D

10. Preliminary Unbalanced Weighted Average Data AAR-422 Fire Safety R&D

11. NEA Minimization Data • Inerted Tank Several Times with NEA 95% to Minimizing the NEA Volume Required to Inert the Tank with Half Vent System Blocked (No Cross Venting) • Acquired Data with Computer Data Acquisition System at a Rate of 1 Sample per Second (Approximate) • First did Balanced Run to Give Baseline; Used the Volumetric Average Developed to Make Fair Comparisons with Other Inerting Methods • Results Illustrated Modest Improvement with Simplest Deposit Scheme AAR-422 Fire Safety R&D

12. NEA Minimization Data - Best Data AAR-422 Fire Safety R&D

13. Unbalanced Weighted Average Data AAR-422 Fire Safety R&D

14. Summary • Model Results Consistent with Existing Knowledge Base But VTE Slightly Higher in These Experiments • This is Believed to be due to Better Measurement Techniques Developed • Depositing in an Efficient Manner Can Greatly Simplify Manifold Design and Even Improve Inerting Efficiency • Still Need to Verify Results in Full-Scale Test Article AAR-422 Fire Safety R&D