A Sparrowhawk goes to hook onto the trapeze of the USS Akron . Source: U.S Navy Naval Historical Center During the 1920s and 1930s, the U.S. Navy began experimenting with rigid airships as military assets. Following the end of World War I, the Navy envisioned the rigid airship as an effective and efficient means of patrolling and monitoring the large amounts of ocean that border the United States to the East and the West.  They were seen as a cost-effective alternative to tra