The search for people in a critical situation is often complicated by the fact that it has to be conducted on a large territory. It is even more difficult to detect them from the air in the mountains, in the forest or in bad weather. Therefore, those in distress, having seen a plane or having heard the sound of an engine, should use any available means of alarm to give distress signals indicating their location.
Possible means of alarm and distress signals in emergency conditions and extreme situations, their application and effectiveness.
This is primarily a combined signal cartridge PSND. Its daytime end is filled with a composition that, when burning for thirty seconds, forms thick puffs of bright orange smoke, and the night (in the dark it can easily be determined by the indentation in the cap) burns with a bright raspberry flame.
type RPSP-40. Detailed instructions are usually printed on its body. Nevertheless, for its most effective use, you should adhere to a few simple rules. It is better to hold the rocket in a bent left hand just above the head, pointing strictly vertically upwards. So that at the moment of jerking with an ignition cord she does not change direction or slip out of her hand, her palm must first be wiped dry.
In recent years, work has been underway to reduce the weight and volume of signaling devices so that the number of cartridges stacked in the emergency kit can be increased. An example of new developments is the so-called mini-signal, weighing only 9 g, about 10 cm long, 1.5 cm in diameter. Its smoke is visible at a distance of 9 km, and fire at night even at 25 km. Voluminous, heavy signal missiles were replaced by mortar cartridges fired by a firing mechanism no larger than a fountain pen. Such a set consists of ten fifteen-millimeter signal cartridges-mortars laid in a pantontash tape.
To signal the trigger button of the firing mechanism lead into the upper (safety) cutout on the body. Then, having unscrewed the safety cap from the chamber, screw it into the threaded slot of the firing mechanism to failure. To avoid injury from an accidental shot, the hand should not overlap the upper section of the mortar. Having screwed the cartridge, the trigger button is transferred to the lower cutout, cocking the mainspring. Now everything is ready for action. Having tightly squeezed the mechanism in the arm extended upwards, with the thumb they pull the trigger button to the side (to the left). A shot and a mortar, flying up to 50 60 meters, flashes a bright red star.
Various tracer cartridges are widely used. They can signal not only from special revolvers, but also from any type of small arms rifles, pistols. With all the variety of pyrotechnic signaling devices, they all have one very significant drawback: their visibility range is very limited and, in addition, against a color background (for example, a yellow sandy desert background), orange smoke is visible only at a distance of several hundred meters.
A fundamentally new pyrotechnic signaling device is the so-called radar rocket, developed by National Engineering Science. Relatively small in dimensions, its weight is 453 g, length is 20.6 cm – it rises to a height of 1500 1800 meters with the help of a miniature rocket engine running on solid fuel. Having reached its climax, the rocket explodes, throwing out a cloud of dipole reflectors. This cloud is held in the atmosphere for an hour and can be detected by any locator at a distance of more than 200 km (Chenoweth, 1967).
The simplest distress alerts.
Quite often, complex technical structures, devices created using the latest advances in science and technology, leave simple, but very effective devices in the shadow. For example, a signal mirror. Man is known to have a conservative thinking. By virtue of which it is difficult for him to imagine that the sunbeam, known even in childhood, can at least to a small extent compete with the brainchild of radio, pyrotechnics and electronics. Nevertheless, it was the sunny bunny of the signal mirror made by Chechoni from a wooden plank pasted with a staniol from under a bar of chocolate that turned out to be the only signal that the pilot noticed in a timely manner.
Probably, if skeptics knew that at a 130-degree angle of sunshine, the brightness of a light bunny is 4 million candles, and at an angle of 90 degrees, it increases to 7 million candles, the distrust experienced in a signal mirror would quickly dissipate. From an airplane flying at an altitude of 1.5 km, such a flash is detected at a distance of up to 24 km, i.e., earlier than any other visual signal.
To signal distress signals at night in some countries produce special flashing lights, beacons. Automatically giving bright flashes of light at regular intervals. For example, the British company Strobe Ident constructed such a lighthouse with a length of only 20 cm and a weight of 250 g. A xenon lamp mounted in the device gives flashes that are visible at a distance of 11 km. The beacon is powered by a lithium battery that can be stored for 10 years..
For a long time they used the smoke of the fire as a call for help. And today, the fire remains one of the most effective means of alarm for distress signals. In order to give a signal in a timely manner, that is, immediately when an airplane or helicopter appears within sight, the fuel for bonfires must be prepared in advance. It is necessarily folded in open places, a clearing, a meadow, a hilltop. Otherwise, the thick branches of the trees will hold up the smoke, and the signal will go unnoticed. To make the smoke blacker and denser, fresh fire, green foliage of trees, raw moss, etc. are added to the bonfire after it has flared up..
In a desert area where there may not be enough fuel, instead of a bonfire, cans of sand soaked in lubricant are used. The signal bonfire is set on fire only when the search plane (helicopter) is already in the zone of visibility or audibility, or radio communication has already been established with it. In winter, the signal fire should be covered from the snow with a spruce.
You can attract the attention of the aircraft crew, if there is no other way, by unmasking the terrain: trampling geometric figures in the snow, cutting down a bush, etc. If the tent is made of bright fabric, it must be stretched out in the open. Pilots can use a canopy of parachute for visual signals. 3 pieces of parachute tissue&# 215; 5 meters tied to the top of a tree, visible from afar on a contrasting green background of foliage.
The dome of the parachute, so that it is better visible, can be stretched with the help of slings over a small body of water: a pond, a stream. In the absence of a radio station for transmitting the most important messages from the ground to the plane of the plane (helicopter), an international signal code table has been developed. Signs are recommended to be made at least 6 meters long and 0.5 meters wide.
Based on materials from the book Man in extreme environmental conditions.