1Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Flammability Reduction Methods: ComplianceOptions

Federal AviationAdministration

AAR-440 Fire Safety BranchWm. J. Hughes Technical CenterFederal Aviation Administration

2Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Reticulated Foam

Advantages:• 100% protection• Passive System• No model – no need for flight testing

Disadvantages:

• Weight• Fuel displacement• Interference with maintenance• Haz. Mat. When out of tank

Certification issues:• Foam pedigree• Voiding• Durability• Interference in tank

3Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Inerting with Stored CO2

Advantages:

• ?

Disadvantages:

• Must be stored on aircraft

Certification issues:

• Needed O2 concentration not known• Fuel solubility• Effect on pumps

4Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Inerting with Exhaust Gas

Advantages:

• Already produced on aircraft

Disadvantages:

• How to obtain

Certification issues:

• Needed O2 concentration unknown• Contaminants unknown

5Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Catalytic InertingAdvantages:

• Possible weight• Less power from aircraft• environmental

Disadvantages:

• ?

Certification issues:

• Needed O2 concentration not known• Fuel solubility• Effect on pumps

6Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Rapid Ventilation

Advantages:

• Cost• Weight

Disadvantages:

• Loss of fuel• Environmental• Need for in-tank monitoring

Certification issues:

• Tank flammability verification

7Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Misting Fuel Vapor

Advantages:

• Possible weight savings• Possible lower cost

Disadvantages:

• Loss of fuel• Environmental• Safety issues

Certification issues:

• Post crash implications• Failure modes• In-tank hydrocarbon measurements

8Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Nitrogen Inerting

• Cryogenic Nitrogen

• High Pressure Stored Nitrogen

• Ground Based Nitrogen

• Two Flow Nitrogen

• Full Time On Demand Nitrogen

9Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Cryogenic Nitrogen

Stored: Too heavy

Manufactured: Developing technology

10Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

High Pressure Stored Nitrogen

Too Heavy

11Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Ground Based Nitrogen

•Logistics•Manpower

12Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Two Flow Nitrogen

• Present system of Choice

13Federal AviationAdministration

FAA Fire Safety BranchSeptember 9-11

Full Time On Demand NitrogenAdvantages:

• Less power from aircraft

• Environmental

Disadvantages:

• Weight

• Vent valve