Parachutes

Strictly speaking, the parachute is not a means of travel or transport but a safety device for escaping from flying machines, balloons or aircraft, in difficulties.The single aim of the parachute is to slow down the rate of descent, and to remain balanced while doing so, so that the person can land safely on the ground. It is hardly surprising that one of the first people to suggest the idea of the parachute was Leonardo da Vinci in the late 1400s. He sketched a cloth-covered wooden frame in the shape of a pyramid with a man hanging underneath.

Click here to make your own parachute using Leonardo's design

It wasn’t until 1783 that a Frenchman, Louis Lenormand devised a parachute and successfully jumped first from a tree and later from a high tower in the town of Montpelier. The first ‘real’ parachute jump was on 22 October 1797 at Paris when Andre-Jacques Garnerin dropped from a balloon at a height of 680m, using a canvas hemisphere as a parachute. Unfortunately the parachute had no vent to allow the air caught underneath it to be released, so throughout the descent the parachute and Garnerin swung violently from side to side. He landed safely but had the added distinction of becoming the first person to suffer from airsickness! For his second jump he had a hole made in the top of the canvas hemisphere.

On 21 September 1802 Garnerin made the first parachute drop in the UK. He landed safely near St Pancras Church in London and was immediately seized by a violent fit of vomiting because he had used a parachute with no centre vent. The first parachute jump to escape danger was made by Jordaki Kurapento when his Montgolfier balloon caught fire over Warsaw, Poland in 1808. This is the only recorded instance of ‘bailing out’ prior to the advent of powered aircraft.

Nowadays the use of modern lightweight fabrics and a much greater understanding of parachute aerodynamics have resulted in many different types of parachute, from the large hemispherical variety to the small rectangular ‘chutes used for aerobatic and display parachute drops.

 

Parachute Problems

Not everything in our world is certain and comfortable. Some people live in places where flood or drought can threaten their lives. When this happens, help needs to be flown in by aid agencies. The problem is getting the supplies of food, shelter, medicine and water safely from the aircraft to the people on the ground where there are no proper runways.

Parachutes are the main way of doing this. But how does a parachute work?

Try this experiment:
  1. Take a small object like a bottle top and a flat sheet of paper.
  2. Hold both out in front of you at the same height above the ground.
  3. Drop them at the same time.
Q: Which landed last? ............But why?

 

It all comes back to the fact that air pushes evenly in all directions, including up. The air resists the weight of both objects – both fall to the ground. But the paper has a larger surface area than the bottle top. The larger surface means that the air has more to push against, so the flat paper takes longer to get to the ground.

Do the same activity again. This time, instead of holding the paper out flat, hold it end on, or crunch it into a ball.

The problem!

You have to design a parachute which will get an object (try a single section cut from an egg carton) safely to the ground
- A piece of plasticene will provide the weight of a cargo.
- You’ll launch it by throwing it up in the air.

Here are some issues from you to investigate.
You will have to design the experiments.

Record what you discover in your notebook
Can you think of any other real life situations where parachutes are used?
Text and graphics courtesy of The Flight Experience, Sponsored by Bombardier Aerospace.