Drogue parachute

A B-52H Stratofortress from the 307th Bomb Wing deploying its drag chute for landing

RAF Typhoon using a drag parachute for extra braking after landing

A drogue parachute is a parachute designed to be deployed from a rapidly moving object in order to slow the object, or to provide control and stability, or as a pilot parachute to deploy a larger parachute. It was invented by Giovanni Agusta in 1911.

Design and operational characteristics

A drogue parachute is more elongated and has a far smaller area than a conventional parachute, and thus provides less drag. This means that a drogue parachute cannot slow an object as much as a conventional parachute, but it can be deployed at speeds at which conventional parachutes would be torn apart.^[1]

The drogue parachute's simpler design allows for easier deployment. Where a conventional parachute could get caught in itself while unfolding and fail to inflate properly (thus not slowing the falling object as much as it should), the drogue parachute will inflate more easily and more reliably to generate the expected amount of drag.

History

The drogue parachute was applied for the first time in 1912 by a Russian inventor Gleb Kotelnikov, the same man who had introduced the knapsack parachute a year before. On a road near Tsarskoye Selo (now part of St. Petersburg) Kotelnikov successfully demonstrated the braking effects of parachute by accelerating a Russo-Balt automobile to the top speed, and then opening a parachute attached to the back seat.^[2]

In aviation, drag chutes were used for the first time in 1937 by the Soviet airplanes in the Arctic that were providing support for the famous polar expeditions of the era, such as the first manned drifting ice station North Pole-1, launched the same year. The drag chute allowed airplanes to land safely on the ice-floes of smaller size.^[2]

Use

Parachuting

Drogue parachutes are sometimes used to deploy a main or reserve parachute by using the drag generated by the drogue to pull the main parachute out of its container. The most familiar drogue parachute is the one used in this manner in parachuting. Such a drogue is referred to as a pilot chute when used in a single user (sports) parachute system. The pilot chute is only used to deploy the main or reserve parachute; it is not used for slowing down or for stability. Tandem systems are different; to reduce the terminal velocity of the pair of tandem jumpers, a drogue is deployed shortly after exiting the aircraft. It is later used to deploy the main parachute as on sports systems.

Deceleration

Dual braking parachutes fitted to Jet dragsters

When used as a method of decreasing the landing distance of an aircraft below that available solely from the aircraft's brakes, the device is called a drag parachute or braking parachute.

Braking parachutes are also employed to slow drag racing and land speed record vehicles.^[3]

Stability

Drogue parachutes may also be used to help stabilize direction of something in flight, such as a thrown RKG-3 anti-tank grenade. It is often used to gain control of very fast descents, including those of spacecraft during atmospheric reentry, or nuclear bombs such as the B61 and B83.

See also

• Air brake (aircraft)
• Drogue

References

1. ^ "Abbreviations and Acronyms". Relive Apollo 11. NASA. http://www.nasm.si.edu/events/apollo11/reliveapollo11/glossary.cfm. 
2. ^ ^{a b} Parachuting at the site Divo: The Russian Book of records and achievements (Russian)
3. ^ "North American Eagle Project: Deceleration - High Speed Parachute Systems". http://www.landspeed.com/researchchutes.html. 

External links