The word "parachute" comes from the French "le parachute" - "device that prevents falling." In fact, the parachute only slows down the fall in the air, however, the term has become widespread in Russia and to this day has no synonyms in Russian.
How the parachute works
A modern parachute consists of a huge canopy made of special lightweight fabric, a harness, a small pilot chute, a knapsack, a bag and a form. It is known from a high school physics course that a body dropped from a height falls down. However, attaching a parachute can significantly reduce the falling speed. The reason for this is the force of air resistance that occurs when the open parachute canopy falls.
You can easily feel this power if you quickly lower an open umbrella to the ground. It is noticeable that with a gradual lowering, the resistance force is weaker, and with a sharp one, it is greater. The magnitude of the resistance force is proportional to the area of the dome. It is the canopy that is the supporting part of the parachute and reduces the fall speed to a value that is safe for landing. Particular importance is attached to the correct folding of the parachute. After all, it should fit into a compact knapsack and easily open without the slightest jams. The knapsack parachute was invented by the Russian engineer G. E. Kotelnikov. in 1911.
Modern design
The size and shape of the canopy of modern parachute models can be very different depending on the purpose. In military aviation, mainly circular or square domes are used.
Durable and lightweight silk or cotton fabric is used as the material for the dome. The round shape of the dome is achieved by stitching a plurality of wedge-shaped panels. Their number can reach 28 pieces, and in the case of spare or rescue models - 24 pieces. Moreover, each of them also consists of two or three wedge-shaped stripes. A round window remains in the center - a pole that serves to compensate for the dynamic shock when opening the canopy and to increase stability during movement.
In canopy of a square type, the pole hole is not made, and the stabilization of the parachute during downward movement is achieved through the beveled corners of the canopy. The number of slings for connecting the dome to the harness is determined by the number of wedge-shaped panels.
The material for the slings is a silk or cotton rope with a cross section of 4-6 mm. Such a rope can withstand a load of 120-150 kg. The harness is equipped with shoulder straps. The straps are attached to the slings using metal half rings. In this case, the length of the lines is approximately 6, 5-6, 7 m. Actually, the harness is put on the parachutist's body. When opening the canopy, it is she who evenly distributes the force of the dynamic impact, thereby protecting the parachutist's body from injury and damage.
