Ground-based troops are often in need of additional supplies that must be delivered through the air. Unfortunately, even the most accurate airdrop techniques and systems have resulted in considerable loss of supplies because of how supplies are spread from a ballistic airdrop flight system across such a wide ground drop area. Fortunately, the U.S. Air Force Research Laboratory (AFRL) Aerospace Systems Directorate has just earned a patent for an enhanced precision ballistic airdrop apparatus and method technology. The new airdrop approach places packages from high altitudes but with enhanced positioning accuracy compared to traditional airdrop methods, using available, existing hardware.
“The idea started from the observation that the armed forces could benefit from something in-between low-cost World War II era ballistic parachutes, and highly accurate, but expensive, guided parafoils,” said Dr. Adam Gerlach, a research aerospace engineer with the Aerospace Systems Directorate. According to Dr. David Doman, a principal aerospace engineer with the Aerospace Systems Directorate, the new approach uses parachutes but also involves the wind field as port of a computational factor: “The wind field is used as a source of control power to shape the path of the fall in a beneficial way. We choose the direction of approach of the aircraft toward the release point to obtain as much useful control power from the wind field as possible to reduce the effect of scatter due to differences in package release time from the aircraft.” He added: “After the packages exit the aircraft, our method of timing of the transition from drogue to main parachute, allows for some ability to shape the distribution of the impact of packages on the ground.”
Using computer-aided engineering (CAE), different transition altitudes can be mapped to impact points on the ground for any number of wind fields and package types. Additional computing is performed as the packages are released. “We have developed a fast physics-based method that can compute the best transition altitudes to cause the packages to cluster in desired locations on the ground,” Gerlach said. “The algorithms can be run prior to the release from the aircraft and the transition altitudes can be uploaded to the packages shortly before the drop. For even better control over the impact distribution, the algorithms can also be run in real-time onboard the packages as they fall.”