There are instances when items (e.g., supplies) need to be lowered from an aerial vehicle to the ground. For example, the United States military often lowers supplies from a rotary winged aircraft (e.g., a helicopter) to ground troops. In some instances, there is even a need to deliver mission essential supplies to ground troops engaged in enemy combat. Rotary wing aircraft are typically the transport platform for these supplies. Many times, the aircraft cannot land, and supplies are free-dropped from as high as 150 feet above the ground. Losses of badly needed supplies such as medicine, ammunition, water, and food are high due to the free drop.
An aerial delivery device was developed to provide control over dissemination of supplies through a novel linear braking system. This patented technology covers several linear brake designs for a brake attached to the inside of a helicopter. One example includes a baseplate with a linear brake and a linear brake sleeve. A toggle clamp is also mounted to the baseplate to adjust tension on the linear brake. The brake sleeve provides a constricting force on the rope that slows the movement of a padded bag attached to the rope, and orients the bag so it is pad-side down.
The linear brake, which is partially disposed within the brake housing, includes a braided cable, a collar attached to the proximal end of the braided cable, and a member attached to the distal end of the braided cable. A portion of the rope passes into a bore in the collar, through a tunnel formed by the braided cable and the collar, and exits the braided cable by passing between cable strands. An interface mounted to the baseplate to extend the braided cable constricts the braided cable upon the rope. The collar secures the proximal end of the braided cable to the brake housing, and the member secures the distal end of the braided cable to the interface.
The linear brake is fully developed, and has been used in Afghanistan by the U.S. military for two years. This brake is part of an airdrop system called the Enhanced Speed Bag that includes a rope and a padded bag/crate that can hold up to 200 pounds of supplies. This system has a greater than 90% intact delivery rate from 100 feet off the ground. Testing has shown the Enhanced Speed Bag system has increased survivability of the supplies from 30% to 98%, estimated to save up to $1,500 worth of gear per drop.