Cargo Aircraft Fire Supression - Term Paper Example

The sensors can wrongly detect dust and other aerosols as smoke particles. Since the aircraft crew has no way to visually verify the presence of a fire, any alarm has to be treated as a real fire. If the aircraft is in flight, the pilots need to discharge on-board extinguishing equipment, declare emergency priority over other traffic, and land the aircraft at the nearest airport. If a false alarm goes off before takeoff, the aircraft must return to the gate and takeoff is delayed until mechanics can solve the problem.

These procedures followed to handle the false 'fire alarm' result in considerable loss of time and fuel. Hence current research in this field is geared towards developing systems which are false-alarm-free. Contemporary research activities also explore the use of multiple sensors and computer aided signal analysis and video camera aided fire and smoke indication. Along these lines, the NASA Glenn Research Center has developed a multi-sensor package to read in a wider variety of fire emissions instead of just smoke.

The detector looks for higher concentration of combustion gases along with the smoke, thus developing a more diverse file picture for the sensors. These file pictures with varying gas concentrations and smoke particle sizes are then compared by the multi-sensor package against the values that are characteristic of an actual fire. NASA Glenn also uses MicroElectroMechanical Systems (MEMS) chemical sensors with this new fire detection concept in response to the significant number of false alarms generated by the current fire detectors used on aircraft.

The MEMS sensor system consists of miniaturized carbon monoxide and carbon dioxide sensors, a smoke particle detector, and integrated software. It also has a processor that measures the response of the complete sensor system and signals if there was an actual fire. The resultant system is effective in recognizing the presence of fires while screening out false alarms. Tests conducted by NASA indicate the feasibility of the multi-sensor system. Improvements can still be made to the sensors, the packaging and the software interface, the durability and drill effects of the sensors.

The system also needs to be compliant with the FAA certification criteria. (i)The B737-200 Freighter uses the Securaplane ST 3000 Fire Detection System which detects fire that originates in the lower cargo compartments of the aircraft. Radio communication links are used instead of wiring between the different limits of the system; this minimizes the quantity of wiring required, decreases the system weight and increases reliability.The system has nine smoke detectors (four in the forward cargo and five in the aft cargo compartments) mounted in the ceiling of each lower cargo compartment, one central control unit (CCU) located in the aft wall of the forward cargo compartment with a configuration module (CM), one control display unit (CDU) on P-5 overhead panel, two circuit breakers at P-18 panel and associated wiring.

The System satisfies the FAA required Class "D" to Class "E" cargo conversion. The System can detect smoke anywhere within any cargo compartment within one minute at at-least two SDU locations. (ii)Fire extinguishing systems:The US Patent