Striking Oil: The First American Bombing Raid over Europe in World War II

The U.S. Army Air Forces (AAF), the predecessor to the U.S. Air Force, prepared for global war in January 1942. With the enemy in Europe and Asia, Allied forces would have to span the globe, and rely heavily on air power if they wanted to be successful. One plan focused on establishing American air forces in the China-Burma-India Theater of Operations. Light bombers, cargo planes, and fighters would establish the Tenth Air Force, which would include a group of 23 B-24 Liberator heavy bombers, commanded by Col. Harry Halverson. With handpicked crews, this group became known as the Halverson Project or HALPRO. Their planned assignment included raids on Japanese Home Islands. 

Halverson, who became a pilot during World War I, had vast experience in the air.  In 1924 he served as ground support organizer for the Army’s Round the World Flight in India.[i] He also flew with American aviation pioneers Ira Eaker and Carl “Tooey” Spaatz. The group set a record in 1929, flying for 150 hours with air-to-air refueling. Because of his decades of aviation experience, Halverson was an obvious choice for long range bombers.

Originally HALPRO planned to fly from Florida to Brazil and then on to Africa, and by stages to Chekiang, China. But by mid-May 1942 a Japanese offensive blocked the plan by threatening Chekiang.  Alternative plans were needed to employ these heavy bombers. The British could support a force the size of HALPRO in Egypt. Because of this the AAF Planning Division shifted its focus to attacking German petroleum plants in Ploesti, Romania. From Egypt the B-24 had the range to make the raid possible. In early stages of the war this type of strategic bombing had not been tested. Military leadership hoped that by attacking key resources, such as petroleum or ball bearing production plants, they could cripple enemy manufacturing and military operations.   

HALPRO departed the United States on May 22, 1942 for Khartoum, Sudan, and flew on to northeast Egypt.  Having flown around 4,000 miles, maintenance problems grounded some of the arriving aircraft.  This would be the first AAF attack over Europe, and Halverson maintained secrecy and independence of command.

On June 11 at  10:30 p.m., the 13 available B-24s took off for Romania. Halverson directed crews to fly directly to Romania, and return to Habbaniyah, Iraq, even though this route violated neutral Turkish airspace. One crew bombed the Romanian harbor of Constanta and turned back. The other 12 Liberators approached Ploesti individually at 14,000 feet.  Bad weather frustrated navigators, making the bombing inaccurate and creating only light damage, if any. Antiaircraft fire and a few enemy fighters were encountered as the crews dropped 24 tons of bombs. Halverson’s aircraft and three others landed at Habbaniyah, five landed at other fields in Iraq and Syria, and four landed and were then interned in neutral Turkey.[ii]  With little damage inflicted and some crews interned, Allied leadership considered the raid a failure.  Gen. Dwight D. Eisenhower remarked dryly that the raid “did something to dispel the illusion that big planes could win the war”.[iii]

While this first raid inflicted little damage, it did prove that long-range bombers could penetrate enemy air space and attack defended targets. After the Ploesti raid HALPRO Liberators and their crews became the first American heavy bombers dedicated to the Mediterranean Theater. Joined by B-17 Flying Fortresses from India, they became the 1st Provisional Bombardment Group (PBG), and the 376th Heavy Bombardment Group. They went on to attack the German Afrika Corps in North Africa, and the Italian Navy at sea.  Completing 450 missions after the first Ploesti raid, HALPRO, the 1st PBG, and the 376th sustained the loss of 1479 officers and men. [iv] Halverson earned the Silver Star for leading the Ploesti raid. [v]

The HALPRO Ploesti raid was less effective a mission than it was a foreshadowing. American strategic bombing improved against distant and difficult targets.  Heavy bombers flew in tight formations to concentrate bombs hits and defensive fire. Weather forecasting and bombing radar improved success rates.  And by late in World War II, the B-29 could carry over ten tons compared to the two tons carried by each B-24 in the first Ploesti raid.  Attacking petroleum production plants continued throughout the war and became a hallmark of American strategic bombing campaigns. Their missions included targets such as ports, railroad lines, and U-boat pens. Attacking fixed strategic targets by the air proved a huge success that hastened the end of the war in Europe.  

[i] See: Caroll V. Glines Around the World in 175 days: The First Round-the-World Flight ( Washington, Smithsonian Institution, 2016) & Patrick Stinson, Around the World Flights: A History ( Jefferson NC, McFarland, 2011) p.42.

[ii] See: John Sweetman, Ploesti: oil strike(New York, Ballantine, 1974. &

[iii] See: John G. Bunnell, KNOCKOUT BLOW?, Thesis for the School of Advanced Air and Space Studies/Air University, Maxwell AFB, Alabama 2005, pp 18-19.

[iv] See - Collected 5/18/17