Such requirements define a drop profile generally known as "High Altitude, Low Opening" drops or "HALO" drops. They arise from the necessity of improving the tactical success of airdrop operations while at the same time increasing the survivability of cargo aircraft and crew. Moreover, in the light of the low probability of equipment recovery associated with military airdrop in general and humanitarian relief in particular, those requirements also aim at producing the cheapest cargo equipment possible.
Meeting such criteria is challenging given that it requires a knowledge base on parachute inflation and flight dynamics that goes well beyond what is needed by current low altitude and low speed airdrop operations. In particular, such a detailed knowledge base must be general enough to cover the behavior of parachute systems that are not in the current inventory. On the other hand, meeting the low cost requirements for designing, developing and fielding the systems of the future requires that this new knowledge be acquired cheaply via the smart use of computer modeling, computer simulation, wind tunnel testing and sub-scale drop-testing.
In the course of the 1999 and 2000 fiscal years the PRG has been conducting a basic research program aimed at furthering aerodynamic knowledge in the area of parachute inflation and flight. The program is composed of three basic tasks that would involve computer modeling, wind tunnel testing, half-scale testing and full-scale testing. This research project is pursued in close collaboration with the members of the Airdrop Technology Team (Science and Technology) based at the U.S. Army Soldier Systems Center in Natick, MA. and funded in part by the U. S. Air Force Office of Scientific Research. These tasks are geared towards the study of the inflation and flight of the basic cruciform and round parachutes as used in HALO cargo airdrops and can be summarized as follows: