What’s the reason for keeping a hole in the center of a parachute?

What could possibly happen if there was no hole in the middle of the parachute to let some of the air escape? The problems for hole-less parachutes were prominent during the First World War when paratroopers would use parachutes without holes and consequently faced two serious risks.

The first risk arose when the folded parachute opened up, as it would often stop the free fall with a sudden jerk in mid-air. This jerk was so severe that it was enough to wrench the muscles and joints of the bones of the paratrooper very painfully. A hole in the parachute allows the air to escape so that the air pressure wouldn’t open the parachute quickly. By letting a little bit of air escape while descending, the parachute would open gradually, and it would also apply a gradual brake on the free fall. However, this aspect of the parachute had not been taken into consideration during the war.

Another risk that was encountered by the paratroopers was the uncontrollable swinging movement of the descending parachute, which causes the person to look like a pendulum from afar. The increasing pressure of air that fills up the dome-shaped parachute would raise one side of the contraption in a swinging motion that lets the air escape unconventionally. The escape of air on the said side is followed by a peculiar movement in which the opposite side would swing upward as air pressure increases in the other part. The swings would continue uncontrollably until the paratrooper drops on the ground. If the paratrooper happens to be at the far left or right while swinging, he will experience an impact on the ground where his slanted body would fall helplessly sideways instead of being able to perform a controlled landing with both feet on the ground that is usually followed up with a rollover. A sideways fall or drop would be painful and might even cause an injury on the hip bone. Such accidents took place from time to time in those days, as those who manufactured parachutes haven’t figured out how to top the swinging motion mid-air.

Today, the modern parachute is vastly superior to its predecessors, and it is extremely safe because of the added ventilator that looks like a hole in the center. The hole allows the air to escape so that the parachute would not swing the paratrooper left and right. Furthermore, the folded parachute opens in a gradual manner and wouldn’t produce a sudden jerk for the one using the parachute.

When Did They Add Holes on the Parachutes?

It was believed that holes were added on parachutes right after World War I, as many surviving soldiers have reported problems with their parachutes, thus allowing the manufacturers to take the feedback and improve upon their design.

One of the first people who were adamant in enhancing the features and capabilities of the parachute was Major Edward L. Hoffman, who served under the United States Army. Hoffman put together a team that would focus on creating a new design for the parachute. This team was successful in adding several features to the contraption, including the ability to store the parachute in a soft pack, a small parachute called the pilot chute that would deploy first before the main parachute, a ripcord that allows the paratrooper to activate the parachute with only a pull of a string, and a hole at the middle that lowers air pressure. This improved contraption would eventually be called the Parachute Type-A.

The parachute was tested by Leslie Irvin, an experienced stunt-man for movies, in 1919, and his demonstration was successful. The following year, the Parachute Type-A would be put into production and would be used by soldiers during the Second World War. Because of Hoffman’s efforts in developing a new parachute for soldiers, he was awarded the 1926 Robert J. Collier Trophy, which is an award given for those who had significant contributions or achievements in aeronautics and astronautics in the United States.

Seeing how parachutes can slow down the speed of any descending object in the air, the Soviet Union developed the drag chutes that are used by aircraft rather than people. The team that invented the drag chute was led by GlebKotelnikov, who also invented the knapsack parachute before it was used for the Parachute Type-A, although his invention first used hard casing before switching to soft cases for less weight. These drag chutes were not used for war at first, as they were instead utilized for assisting people who were on the polar exhibitions in the country. The drag chutes allow the planes to land smoother, and it also enabled the planes to land safer in a softer ground like drift ice. Drag chutes would eventually be used for World War II a few years after its invention.