The construction of a vertical wind tunnel at the United States Army Yuma Proving Ground, is currently ahead of schedule, with the most visually dramatic aspect taking place next week. It is the largest such tunnel ever built.
Starting Monday the 75-foot tall structure's four reinforced concrete sidewalls will be raised with a massive 150-foot tall crane.
The completed wind tunnel will be used by elite parachutists to practice maneuvering and steering their bodies while freefalling, suspended in a vertical column of air gushing at 120-miles-per-hour. They will show the tunnel to the media on Monday.