After World War I, there was a consensus that the airplane had a place in warfare, but the different missions they would be used for was still a matter of debate. Colonel Billy Mitchell, a World War I air commander, believed that control of the air would matter a lot in future warfare.
According to a biography at the website of the National Museum of the Air Force, Mitchell spent time after the war arguing his case – often alienating many senior officers in the process. So, despite the fact that Mitchell had led over 1,400 planes during the Battle of St. Mihiel, won control of the air, and devastated German forces, not many people were willing to listen to the air warrior.
In one case, Mitchell considered the effect air power could have on the huge, lumbering ships of enemy navies. Many higher ups blocked his proposed tests to prove his theory but he got the chance to show what air power could do to ships partially due to the Washington Naval Treaty of 1921, which called for the United States to scrap or otherwise dispose of large portions of the United States Navy.
The Navy had tried to block Mitchell with a rigged test involving the old battleship USS Indiana (BB 1), but Congress found out about the way the Navy rigged it, and ordered new tests.
So the Navy agreed to let planes drop bombs on the obsolete battleships USS Virginia (BB 13), USS New Jersey (BB 16), USS Alabama (BB 8), and Ostfriesland.
The first of these ships to face Mitchell's bombers was the Ostfriesland on July 20, 1921. According to an official U.S. Navy history, Mitchell's planes dropped a number of smaller bombs – scoring some hits. The real damage was being done by near-misses, which started flooding. The next day, further attacks were made with bigger bombs, and the Osfriesland sank after a number of near-misses.
The next attack was on the old battleship USS Alabama on September 25, 1921. A series of bombs scored hits, but while one 1,000 pound bomb and one 2,000 pound bomb did a lot of damage, the real killing effect came from five near-misses, which caused Alabama to sink. On Sept. 5, 1923, Mitchell's bombers would sink the battleships USS Virginia and USS New Jersey.
The results, though, didn't completely sway high-ranking officials. When Mitchell made intemperate remarks after the loss of the Navy dirigible Shenandoah, he was court-martialed and dismissed from the Army. He would die in 1936, five years before the attack on Pearl Harbor.
Below is video from Mitchell's 1921 and 1923 tests. Take a look and see a preview of what planes would do to ships in World War II.