In 1921, Army Brig. Gen. Billy Mitchell proved airplanes could sink battleships. Three years later, he predicted Japan would launch a surprise air attack on Pearl Harbor at dawn. Navy and Army brass dismissed him. They court-martialed him, forced him out, then spent the next two decades building more battleships.
On Dec. 7, 1941, Mitchell's predictions were proven right, but it was too late.
The Navy's Rigged Test
Mitchell was a veteran of the Spanish-American War and World War I. He spent the late 1910s vocalizing how airpower could dominate the seas. The Navy was not amused by his assertions, and instead hoped to continue massing its battleship fleet.
Chief of Naval Operations Adm. William S. Benson summed up the Navy's view during this time: “I cannot conceive of any use that the fleet will ever have for aircraft. Aviation is just a lot of noise.”
In late 1920, the Navy hoped to silence the WWI hero as he continued to argue battleships were obsolete. So, they conducted their own anti-naval test using airplanes on the USS Indiana, an old battleship from the Spanish-American War.
Navy aircraft dropped dummy bombs filled with sand to mark where they hit on the ship, then crews detonated massive explosives at those spots to simulate an aerial attack. The damage was devastating and the ship sank in shallow water.
When the test ended, the Navy drew a different conclusion. Capt. William D. Leahy released a report asserting that “the entire experiment pointed to the improbability of a modern battleship being either destroyed or completely put out of action by aerial bombs.”
The Navy hoped this would silence Mitchell, who'd been telling Congress the Air Service could sink any battleship and that funding should shift to modernizing Army aircraft.
Nothing was announced from the tests. Nothing about the results appeared in U.S. newspapers. The Navy kept it quiet.
However, in December 1920, two dramatic photos showing massive bomb damage from the tests appeared in London Illustrated News. Seven more surfaced in The New York Tribune. Congress and the press erupted as the test was shown to be rigged.
Secretary of the Navy Josephus Daniels scrambled to release Leahy's report publicly, hoping it would calm the storm. It didn't. Details emerged that challenged the Navy's conclusions: no live bombs had been dropped at all.
The Indiana test had proven nothing.
Mitchell Gets His Shot
After the Indiana scandal, Secretary of War Newton Baker and Secretary of the Navy Josephus Daniels agreed in February 1921 to joint Army-Navy exercises. Daniels couldn't afford another embarrassment. The exercises, nicknamed Project B, would test to see if Air Service bombers could attack and sink several obsolete ships.
Mitchell, who had commanded nearly 1,500 Allied aircraft at the Battle of St. Mihiel in WWI, formed the First Provisional Air Brigade at Langley Field, Virginia — 150 aircraft and 1,000 Air Service personnel from across the country. He brought in Alexander de Seversky, a Russian Imperial Naval Service veteran who had attacked German destroyers during WWI. Seversky taught American pilots the “near miss” technique: dropping a bomb close enough to a warship to generate an underwater pressure wave that rips hull plates apart.
Meanwhile, Army ordnance engineers developed a 2,000-pound bomb specifically designed to kill battleships.
The tests began in June 1921 off the Virginia coast. As Mitchell flew overhead to observe, Navy aircraft went first, attacking a German submarine and the old battleship USS Iowa with more dummy bombs. The Navy refused to use live-ordnance as the Army had demanded. Instead, the ship was crewed and allowed to maneuver. Only two of 80 bombs hit the Iowa. The battleship advocates that witnessed the test were reaffirmed in their beliefs.
Then came Mitchell's turn.
His targets included captured German warships from WWI, including the battleship Ostfriesland — considered unsinkable due to its compartmentalized design that could easily contain flooding.
The Navy set strict rules designed to protect the ships. Mitchell's planes couldn't use aerial torpedoes. They'd be limited to just two hits on battleships with their heaviest bombs. Ships had to sink in at least 100 fathoms of water — so the Navy picked a spot 50 miles offshore, cutting the time Mitchell's bombers could spend over the target.
But Mitchell had learned his lesson from the Indiana debacle. On July 21, 1921, he violated the Navy's rules and ordered his Martin bombers to drop six 2,000-pound bombs instead of the permitted number. He told his pilots to aim for near-misses in the water beside Ostfriesland rather than direct hits on the deck which would have likely absorbed the explosions but kept the ship afloat.
The bombs detonated close enough to crack the battleship's hull. Twenty-two minutes later, Ostfriesland rolled over and sank beneath the Chesapeake Bay.
Naval officers watching from the USS Henderson stood in stunned silence. Some reportedly wept.
The Warning Nobody Wanted to Hear
The Navy remained unimpressed with the test results. Mitchell kept fighting for change. After a 1924 inspection tour of Japan and the Pacific, he returned with a 324-page report warning that Japan would eventually attack the United States.
The report outlined Japanese expansionist ambitions and described in detail how a hypothetical attack on Pearl Harbor could unfold — including aircraft striking at 7:30 a.m. with devastating results leading to a protracted naval conflict in the region.
The Army War Plans Division dismissed the forecast as “exaggerated” and “unsound.”
In 1925, the General Board of the Navy insisted: “the battleship is the element of ultimate force in the fleet, and all other elements are contributory to the fulfillment of its function as the final arbiter in sea warfare.”
Mitchell's relentless criticism of Army and Navy leadership earned him a court-martial in 1925 for insubordination after he accused them of “almost treasonable administration of the national defense.” He was found guilty and suspended from duty for five years. Rather than serve the sentence, he resigned.
Mitchell continued to advocate for airplanes and airpower, as well as an independent Air Force. He died in 1936, five years before Pearl Harbor proved him right.
World War II and Naval Aviation
In November of 1940, British biplanes attacked and sank numerous Italian ships, including their modern battleships, during the Battle of Taranto. Meanwhile, as the U.S. Navy began moving its Pacific Fleet to Pearl Harbor, Navy officials still refused to acknowledge the importance of airpower in naval warfare.
On Dec. 7, 1941, the Japanese attacked Pearl Harbor at 7:55 a.m. as well as Clark Field in the Philippines — within an hour of Mitchell’s 1924 predictions. Three days later, Japanese aircraft sank HMS Prince of Wales and HMS Repulse off Malaya, making it brutally clear that the age of the battleship was over.
If Navy leadership had listened to Mitchell instead of rigging tests to protect their battleships, countless American sailors might have survived Pearl Harbor. Instead, the Navy learned the lesson Mitchell tried to teach them 20 years earlier — at the cost of eight sunken or damaged battleships and 2,403 American lives.
It wasn’t until June 1942 that the U.S. Navy leveraged its airpower to maul the Japanese fleet at the Battle of Midway.
Congress posthumously awarded Mitchell a special Congressional Medal of Honor in 1946 for his contributions to military aviation. The B-25 Mitchell bomber, which carried out the famous Doolittle Raid on Tokyo in 1942, was named after him — the only American military aircraft ever named after a specific individual. Today, Mitchell is considered the father of the U.S. Air Force.
