100 Years Later: The Ostfriesland Test and the Rising Popularity of Air Power

By Laura Orr
HRNM Director of Education

General William "Billy" Mitchell (U.S. Army)

At the turn of the twentieth century, many U.S. admirals believed that planes could never sink a ship. To them, the very idea of devoting a portion of the Navy’s budget to airpower seemed laughably unsound. However, in 1921, U.S. Army General William “Billy” Mitchell taught the Navy’s naysayers that airpower forged the future of human warfare. From June 21 to July 21, Mitchell led a team of pilots from the U.S. Army Air Service in a bombing test against five target ships: USS Iowa, an old U.S. battleship converted to a radio-controlled target ship; G-102, a captured German destroyer; a German light cruiser, Frankfurt; a submarine, U-117; and the German battleship Ostfriesland. The results of the “Ostfriesland tests” stood the world on its head. Mitchell and his fliers sank all of the German vessels, including the Ostfriesland.

For years, high-ranking American admirals argued that airplanes would never revolutionize combat. Battleships, they said, would always be the Navy’s future. Chief of Naval Operations Admiral William Benson commented, “I cannot conceive of any use that the fleet will ever have for aircraft. . . . The Navy doesn’t need airplanes. Aviation is just a lot of noise.” Secretary of the Navy Josephus Daniels agreed. He also derided Mitchell’s plan, saying, “I would be glad to stand bareheaded on the deck or at the wheel of any battleship while Mitchell tried to take a crack at me from the air. If he ever tries to aim bombs on the decks of naval vessels, he will be blown to atoms long before he gets close enough to drop salt on the tail of the Navy.”

Mitchell aimed to prove the battleship establishment wrong publicly. His testimony before the House Appropriations Committee in January 1921 led to two Congressional resolutions forcing the Navy to provide the targets for Mitchell’s weapons tests. The admirals did not want to conduct the tests, but they also did not want to appear obstructionist to the wishes of Congress. Confident that even a decrepit battleship could withstand a few hits, the admirals believed the tests could be used to observe the type of damage bombs might cause.

The Navy greatly restricted the manner in which the Air Service pilots could conduct their attacks. The pilots could not use aerial torpedoes or score more than two hits with their heaviest 2,000-pound bombs. This latter restriction did not matter to Mitchell, however. He intended his pilots to avoid direct hits, in favor of near misses, because when the bombs exploded underwater, they would inflict maximum damage on a ship’s hull.

Sailors and dignitaries aboard USS Henderson (AP 1) watch the tests (Naval History and Heritage Command)

Mitchell’s bomb tests would take place in the Atlantic Ocean, fifty miles from the mouth of the Chesapeake Bay. The dignitaries observing the test didn’t believe that Mitchell’s fliers stood a chance. The German ship Ostfriesland had taken eighteen hits at the Battle of Jutland in 1916, hit a mine on the way back to Germany, and returned to action two months later. In addition to having a four-layer steel hull to protect it from mines and torpedoes, Ostfriesland was divided into separate watertight compartments so it couldn’t be sunk by any single hull breach. As the New York Times reported before the tests, “Naval officers are insisting that the fliers will never sink the Ostfriesland at all.”

Starting on June 21, bombing tests took place against the smaller ships. The German vessels were sunk quickly. The naval officers did not exhibit much concern at these proceedings, as their focus was on the Ostfriesland. The main event took place on July 21, 1921, when six Martin MB-2 biplanes and a Handley-Page O/400 attacked Ostfriesland. Over 300 disbelieving observers watched six bombs strike the water right next to the big ship. At 12:40 P.M., twenty-two minutes after the first bomb fell, Ostfriesland sank. Some of the naval officers had tears in their eyes as Ostfriesland and their devotion to battleships sank beneath the waves. In an instant, the U.S. Navy looked weak and helpless.

Ostfriesland hit during the bombing tests, July 21, 1921 (Wikipedia)

Even so, not everyone was convinced by the result. General John Pershing commented, “These tests against obsolete battleships will not, I hope, be considered as conclusive evidence that similar bombs would sink modern types of battleships.” The Joint Army-Navy Board’s report on the tests noted that the ships were unable to maneuver, employ antiaircraft fire, or conduct damage control. Of course, Mitchell pointed out that his forces suffered the most restrictions. They could not use all the ordnance at their disposal, and they could not inflict more than two direct hits. Moreover, under battle conditions, a loaded battleship would suffer secondary explosions. The Ostfriesland went under through the success of the main attack alone.

A cartoon from the Chicago Tribune showing the differing opinions about the Ostfriesland tests (Chicago Tribune)

Mitchell testified to Congress that the test “demonstrated beyond a doubt that, given sufficient bombing planes—in short an adequate air force—aircraft constitute a positive defense of our country against hostile invasion.” In the following years, Mitchell continued to criticize Army and Navy leaders for their dismissal of airpower. Because of this, in 1925, Mitchell was court martialed for conduct prejudicial to good order and discipline. Upon receiving the guilty verdict, he resigned his commission.

But while the Navy and Army were not strongly convinced, both Congress and the general public took Mitchell’s point seriously: aircraft could sink battleships. In the Ostfriesland test’s aftermath, Congress created the Bureau of Aeronautics to manage all aspects of naval aviation. Aircraft would be the future of the U.S. military, as the Second World War confirmed just twenty years later.