Emergency exit is one of the most critical components of passenger safety. It should be perfectly safe for the people to leave the aircraft, in case of emergency evacuation. Therefore, emergency egress systems must meet the most stringent standards.
Emergency exit (Egress) is comprised of various systems. For example, an emergency egress system will consist of an emergency egress door, an emergency egress belt, emergency oxygen, and an emergency flotation device. These are followed by several features, such as, easy to operate buttons, permanently mounted warning signs, permanently fastened emergency flotation devices, quick-release handles, grab handles, push button release, pressure activated locking mechanisms, etc. An important aspect of these systems is their load-bearing capacities. A panel of metal or steel with at least five permanently fixed structural members may be used for this purpose.
Another emergency egress system component is the emergency egress panels (EPSPs), which are mainly used for providing passenger information on emergency egress. They are to be attached either to a permanent fixture or to a moving object. The EPSPs may also comprise emergency door proximity indicators and/or door lock sensors for providing passenger notification on arrival of emergency doors
An emergency egress system (EESS) comprises many other features as well. For example, an emergency egress system may comprise emergency lights, emergency sound and notification system, emergency door sensors, emergency obstruction detectors, seat belts, emergency exit signs, emergency signaling devices, and emergency telephones. Apart from all these, an emergency egress system may also comprise emergency preparedness kits and related materials such as blankets, clothing, personal hygiene items, and medications in case of an emergency. The emergency preparedness kits may also include tools for cutting household wiring, assembling candles, light bulbs, matches, toiletries, and food items.
An emergency egress system may have one or more emergency exits. These include an emergency stairwell, a vertical path with at least one inclined plane, and at least one emergency exit. In addition, an emergency egress system may include at least one exterior exit, one interior exit, and one way doors that open in different directions. The exterior and interior exits consist of at least one exterior door and one interior door that open in various directions. At least one exterior door has a manually operated emergency exit.
The first type of emergency egress system involves a horizontal movement of a person from the upper platform to an exterior point of the building. Such motion is referred to as egress. This means that a person has to make a controlled exit from the building. The person is not supposed to walk horizontally; rather, he or she has to go up and down, and remain in place while moving. Such a motion is called as “stairwelling.”
The second type of emergency egress system 10 comprises a vertical movement of a person from the upper platform to an interior point of the building. Such a movement is known as “retention.” When this mode is used, persons are supposed to stay in their assigned positions at all times, except when they need to cross an object or when they require access to equipment. Persons are also required to cross such objects only when they are told to do so by a fire guard, an adult, or a child.
The third type of emergency egress system 10 comprises a vertical movement of a person from the upper platform to the second operating position wherein a safety belt is required to keep the person’s body weight from being exerted on the rails of the stairwell. This type of system is called “jettison lever 140.” A jettison lever 140 is a member that is at the bottom of the stairwell. When the person climbs the stairs, the jettison lever 140 releases a spring. It is this spring that draws the person through the exit in an emergency situation.
The fourth type of emergency egress system 10 comprises horizontal movement. This means that persons need not ascend or descend the stairs when going up or down. Only when they are going up or down, they have to keep on walking. These “horizontal movement” mechanisms use two types of rapid egress systems: water-tight seal and pressure transfer. Pressure transfer utilizes a pipe that is connected between the stairwell at the top of the staircase and the emergency egress exits.