Smoke or just hair spray?
„Fire detectors in airplanes are very sensitively adjusted. False alarms occur frequently. Up to 100 emergency landings per year due to fire alarms are not unusual,” Albrecht Hopfe, innovation engineer at Aviation in Dresden says.
„Every fire alarm, whether justified or not, causes stress to the crew. Sometimes the cause of an alarm can be clarified easily if, for example, a passenger uses a lot of hair spray in the on-board toilet. Alarms in the cargo compartment are not so easy to clarify: if fresh fruit is on board, whose emanation activates the fire detector, the risk of a false alarm increases,” Albrecht Hopfe reports. “Dust also often triggers false alarms. It is whirled into the plane while it is loaded and unloaded.”
The idea: inventing a smoke detector which only reacts to smoke. “To make alarms more reliable, you have to test a lot. Fortunately, we have long cooperated with a university that has a fire laboratory,” Hopfe states.
The innovative smoke detector must be able to sort out incidents. Scattered light smoke detectors react to optical signatures and trigger an alarm when the optical signature of smoke is detected: „We teach the detector to distinguish between dust and smoke; both substances are very similar in optical terms. To create as realistic test conditions as possible, some engineers even swept an underground parking lot because the dust from rubber abrasion is very similar to that on runways.”