Aircraft Fire Protection Course
Course Outline
- Combustion Fundamentals
- Chemistry and Physics of Combustion
- Thermodynamics of a pure substance, vapor pressure vs. temperature, partial pressure and concentration
- Mole and energy balances, stochiometry, elementary and global reactions, kinetics versus transport rates, flame temperature, flame types (pre-mixed vs. diffusion, laminar vs. turbulent), eigenvalues, modeling approaches (zonal vs. CFD)
- Combustion Characteristics of Liquids
- Classification of liquid flammability, Class B fires, flash point, fire point, flame spread over a liquid, influence of surface tension on flame spread, pool fire, liquid regression rate, turbulent diffusion flame height, effect of wind, soot formation, thermal radiation, optically thin/thick flames
- Historical methods of measuring flammability, anti-misting kerosene, pool v trailing fires, full-scale B720 Crash Impact Demonstration test
- Autoignition temperature (ASTM E 659) vs. hot surface ignition temperature, test data on F-16, F-18 and AV8B, stream vs. spray, effects of ventilation air speed, pressure (altitude) and oxygen concentration, Damkohler number analysis accounting for residence and chemical times
- Data on conventional fuels, hydraulic fluids, engine oils and alternate fuels
- Combustion Characteristics of vapor
- Lower and upper flammability limits, minimum ignition energy, hot surface ignition temperature, effects of mixture temperature, pressure (altitude) and oxygen concentration, sample CFD calculation
- Deflagration vs. detonation, overpressure development and flame acceleration
- Combustion Characteristics of Solid Materials
- Flammability of polymeric materials (Class A fires), pyrolysis, ignition, flame propogation, gravity effects, shrinking, melting and dripping, surface effects, smoldering and transitions to flaming or extinction, smoke generation and smoke density chamber, FAR 25 853 test methods
- Flammability of composites, new FAA test under development, composite vs. Aluminum structures
- Models: simple heat conduction, Fourier and Biot numbers, thermally thin and thick materials, semi-empirical ignition parameters; heat conduction with reactive terms
- Flammability of metals (Class D fires), titanium and magnesium fires
- Hazardous cargo: standard COMAT or others
- Oxygen Enriched Environments
- Limiting Oxygen Index, accelerated thermal degradation, higher flame temperature, enhanced radiation
- Chemistry and Physics of Combustion
- Fire Safety
- Flammability of systems
- Assemblies of materials such as acoustic insulation and seats
- Cabin fires: full-scale FAA tests with and without fuselage breach, effects of wind and ventilation, metrics are time to burnthrough and time to flashover
- Cargo and hidden fires, ventilation effects, oxygen generator fire (DC-9 Everglades)
- Fuel Tanks flammability
- Static vs. dynamic flammability envelops in fuel tanks, out-gassing of O2 and N2, Oswald coefficient, influence of slosh, vibration and mists
- Potential ignition sources
- Combustion, overpressure and tank damage potential
- Electrical and Lithium ion battery fires
- Wiring construction, voltage breakdown, corona discharge, arc tracking, ground fault interrupter, which occurred first: arc or fire? Class C fires, (MD-11, Nova Scotia, Canada)
- Types of Lithium batteries, anatomy of Li ion cell, reaction initiation and runaway, fires in electronic equipment, APU and cargo compartments and specialized protection techniques for each
- Fire Detection
- Radiation spectra of fires, optical, ionization and photoelectric detectors, fire wire, sources of false alarms
- Fire Extinguishing Agents and Systems
- Flame extingsuishment mechanisms, thermal vs. chemical, halons and their replacement agents, nomenclatures, streaming vs. flooding agents, thermodynamics of agent discharge, cup burner test results, required concentrations for extinguishment, effect of clutter, environmental and toxic issues, alternative technologies: mist, solid propellant gas generators, foams, combined methods such as water mist/OBBIGS
- Terrorist Attack Consideration and Debris Impact
- Classification of explosives, TSA test of explosives on-board planes after Lockerbie
- Penetration and perforation, ballistic limit, standard correlations, hydrodynamic ram, Concorde disaster, hydrocodes
- Human Response to Fires
- Burn injury (CRJ-100, Lexington, KY)
- Required passenger evacuation in 90 seconds in commercial planes, (B737 Manchester UK)
- Flammability of systems
- Designing for fire resistance
- Fire Protection Design Criteria
- Aircraft fire zone classification, hierarchy in protection of various compartments from both material selection and fire detection/suppression requirements
- Protection of Cargo and Cabin Areas
- In cabin use of advanced thermally stable and fire retardant materials, fire blocking layer, rely on human for fire detection, hand held extinguishers
- Classification of cargo compartments, fire detection and suppression in cargo compartments and hidden area, calculation of fire suppression agent concentration to maintain desired concentration throughout flight, specialized cargo fire suppression systems by FedEx and UPS
- Protection of Fuel Tank and Fuel System
- Historical fuel tank explosions and evolution of protection methods (B747 New York)
- Critical Design Configuration Control Limitation (CDCCL), prevention of ignition sources, maintenance and inspection, labeling (SFAR 88, EASA D 2005/CPRO)
- Minimization of flammable conditions, OBBIGS, inerting to 9% vs. 12% oxygen, design considerations to obtain target concentrations
- Other technologies: foams, fast-discharge of extinguishment agents, flame arrester, fuel management, results of cost-benefit analyses of various technologies
- Protection of Engine Compartments
- Uncontained engine failures (CF6, Sioux City, IA)
- Kevlar belts, fireproof bulkheads, pressure relief vents, double wall fuel lines, fuel shut off, bleed air duct shut off, fast detection/suppression, maintaining 6% agent for 0.5 sec, fire resistance temperature requirements.
- Fire Protection Design Criteria