Pilot chute

Key takeaways

Pilot chute belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pilot chute to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pilot chute from memory before moving on to harder problems.

Reference excerpt

A pilot chute is a small auxiliary parachute used to deploy the main or reserve parachute. The pilot chute is connected by a bridle to the deployment bag containing the parachute. Pilot chutes are a critical component of all modern skydiving and BASE jumping gear. Pilot chutes are also used as a component of spacecraft such as NASA's Orion.

Deployment methods

Spring-loaded The spring-loaded pilot chute is used in conjunction with a ripcord. When the user pulls the ripcord, the container opens, allowing the pilot chute compressed inside and loaded with a large spring inside it to jump out. Spring-loaded pilot chutes are mainly used to deploy reserve parachutes. They are often also used to deploy the main parachute on skydiving students' parachute equipment. They are also commonly used in drogue parachutes in cars or in planes such as the B52 Bomber.

Pull-out The pull-out and throw-out pilot chutes are identical in construction; the difference is in their connection to the handle and the bridle, and in the way they are packed. With the pull-out system, the pilot chute is packed inside the container. The activation handle is attached to a lanyard, which in turn is attached to the closing pin. The lanyard is also attached to base of the pilot chute, at the point of connection to the bridle. When the user pulls the handle, the closing pin is pulled, opening the container. Continuing the pull, the user pulls the pilot chute out of the container and into the airstream, at which point the pilot chute inflates and pulls the main parachute out of the container.

Throw-out The throw-out pilot chute is the most popular type in use today. The pilot chute is packed in a pouch at the bottom of the container. The handle is attached to the apex of the pilot chute. When the user grabs the handle and throws the pilot chute into the airstream, the bridle extends, pulling the closing pin and opening the container; as the pilot chute continues in the airstream it extracts the deployment bag containing the main parachute from the container. The pull-out pilot chute and the throw-out pilot chute were both invented by Bill Booth.

Drogues Drogues used on tandem-systems are basically large throw-out pilot chutes, but the bridle is anchored on the container with a release system. When the user throws the drogue, the drogue inflates and the bridle extends. The deployed drogue slows down the free-fall speed of the tandem pair. When the user wants to open the parachute, they pull a ripcord, releasing the bridle and allowing the drogue to open the main container.

Types

Collapsible With the advent of smaller higher performance canopies, the drag induced by trailing a pilot chute behind a canopy has become a significant concern. To reduce this drag some pilot chute designs of the Pull-out and Throw-out variety are collapsible. Once deployment of the parachute has occurred a kill line running up the center of the pilot chute bridle becomes loaded. This kill line pulls down on the apex of the pilot chute collapsing it and greatly reducing its drag on the canopy. Some designs replace the kill line with a fixed length of shock cord, which stretches when the pilot chute is moving quickly, allowing it to inflate. When the pilot slows down (after opening a canopy, for example) the shock cord retracts, killing the pilot chute. While this avoids the possibility of pilot-in-tow malfunction due to an un-cocked pilot, it has the disadvantage of requiring significant airspeed to operate. This could cause a delayed deployment if used for a BASE or balloon jump, or any other jump with a low speed deployment. This type may also begin to re-inflate behind a highly loaded, fast moving canopy, negating the usefulness of a collapsible pilot chute.

Vented Pilot chutes for BASE jumping gear are typically larger than skydiving pilot chutes, and often include air vents on the surface. Research on the development of early round parachutes showed that vents can increase stability and reduce oscillation of the parachute. BASE jumpers often use pilot chutes with either apex vents, or ring vents.

See also Index of aviation articles Ballistic parachute Cirrus Airframe Parachute System Drogue parachute Paragliding Parachute Parachute landing fall Parachuting Rogallo wing

References

Illustrations

Worked examples

Example 1 — a first encounter with Pilot chute

Start with the simplest possible case. Write down what Pilot chute claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pilot chute before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pilot chute ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pilot chute

In research: Pilot chute appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pilot chute in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pilot chute is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aerospace engineering, Drogues, Parachuting, so understanding it makes those chapters shorter.
In everyday life: Look for Pilot chute outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Pilot chute in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pilot chute means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pilot chute out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pilot chute in simple terms?

A pilot chute is a small auxiliary parachute used to deploy the main or reserve parachute. The pilot chute is connected by a bridle to the deployment bag containing the parachute.

Why does Pilot chute matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pilot chute?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pilot chute.