The Bockscar, the Luck of Kokura, and the B Twenty-Nine That Nearly Ran Dry Before It Could Land

The Bockscar - a Boeing B-29 Superfortress on permanent display at the National Museum of the United States Air Force in Dayton, Ohio - flew the second atomic bomb mission on August 9, 1945, dropping Fat Man on Nagasaki. What fewer people know is that the mission was compromised before takeoff, the primary target refused to appear, and the crew landed with two engines running dry on the taxiway.

The Mission That Gets Overshadowed

The Enola Gay and the August 6, 1945 Hiroshima mission dominate popular memory of the atomic bombings. The Bockscar’s mission three days later was operationally far more harrowing - stacked with mechanical failures, a botched rendezvous, critical fuel loss, and a primary target that never materialized.

Bockscar was based at Tinian Island in the Marianas, home of the 509th Composite Group, a specially organized B-29 unit whose crews had trained for over a year on a mission they weren’t fully briefed on. Their aircraft had been stripped of most guns to save weight and modified to carry a single oversized weapon.

A Dead Pump Before the Engines Even Started

Bockscar’s regular commander was Captain Frederick Bock - but on August 9, Bock flew a different aircraft. The pilot in command was Major Charles Sweeney, age 25.

During preflight, the ground crew found a failed fuel transfer pump in the forward bomb bay auxiliary tank. That failure made approximately 800 gallons of fuel permanently inaccessible - locked in a tank the crew could not draw from for the entire mission. With Fat Man already loaded and no time to transfer to a spare aircraft, the decision was made to proceed.

They launched into the pre-dawn darkness carrying a weapon they couldn’t put back and a near-full auxiliary tank they couldn’t use.

Forty-Five Minutes Over Yakushima

The plan called for three aircraft to rendezvous over Yakushima Island, off the southern tip of Kyushu, before proceeding together to the target. Bockscar and the Great Artiste - which had flown scientific instruments on the Hiroshima mission - arrived and began circling at approximately 9,000 feet.

The third aircraft, Big Stink, carrying photographic equipment and observers, never appeared at the rendezvous point. A miscommunication had placed it at the wrong altitude. Mission protocol called for a maximum wait of 15 minutes. Sweeney circled for 45.

He finally broke the rendezvous and turned for the primary target, already burning fuel reserves he had no margin to spend.

The Luck of Kokura

The primary target was Kokura Arsenal on the northern coast of Kyushu, one of Japan’s largest military production facilities. Bockscar arrived over Kokura at approximately 10:44 AM local time.

Bombardier Captain Kermit Beahan was required to confirm a visual fix before release. Mission rules were strict: no radar drop. Visual only.

They made three passes. Anti-aircraft fire intensified with each one. Japanese fighters were being reported in the area. On every approach, smoke and haze obscured the aiming point - Beahan could not lock onto the target.

The smoke had drifted from Yahata, a nearby steel city that American B-29s had firebombed the previous night. The residue of Yahata’s destruction had settled over Kokura Arsenal, shielding it from above.

In Japan, the phrase “the luck of Kokura” entered the language after the war. The city was spared because of a fire it hadn’t started.

Three Words Over Nagasaki

With fuel critical and fighters inbound, Sweeney turned for the secondary target: Nagasaki. A return to Tinian was no longer possible. After the drop, the plan shifted to an emergency diversion to Okinawa.

Nagasaki was partly clouded as well. On the first approach, Beahan called for a radar release. Then, seconds before the drop point, he reported a break in the clouds and a confirmed visual fix.

At 11:02 AM on August 9, 1945, Kermit Beahan released Fat Man. The weapon detonated 43 seconds later, at approximately 1,500 feet above the ground. The destruction was catastrophic. Tens of thousands of lives ended within seconds. More followed in the weeks after.

Bockscar banked hard, dove for airspeed, and put distance between itself and the rising column.

The Emergency at Yontan

Sweeney turned toward Okinawa and asked his flight engineer for fuel numbers. The estimate was that they might - barely - reach Yontan Airfield. Radio contact was marginal. The field had no warning they were inbound.

Co-pilot Captain Charles Donald Albury fired colored emergency flares from the windows as they approached, declaring an emergency to a tower that didn’t know who was coming or what had just happened.

They got down. When the ground crew reached the aircraft, the engines were still running. Two of the four Wright R-3350 Duplex Cyclone engines ran dry while Bockscar was still on the taxiway.

Sweeney reportedly stepped out and kissed the ground.

Where the Bockscar Is Now

Bockscar was flown under its own power to Wright-Patterson Air Force Base in 1961 and has remained there ever since. It stands in one of four hangars at the National Museum of the United States Air Force, which is free to the public and houses more than 360 aircraft and space vehicles.

The aircraft is not a replica. It is the original airplane - the same aluminum skin, the same rivets, the same crew stations where Sweeney and Albury and Beahan made decisions no crew should ever have to make. Standing underneath it, the scale of the machine is hard to absorb. Wingspan: over 140 feet. Length: just under 100 feet. Empty weight: approximately 74,000 pounds. Maximum gross weight: over 130,000 pounds. The four Wright R-3350 engines drove 16-foot, four-blade propellers.

The B-29 had serious developmental problems early in its service life - engine fires were common, and the early missions flown from India and China were harrowing. By the time the 509th was operating from Tinian, the airplane had been worked into a proven machine. It was the most technologically advanced bomber of its era, and it showed.

The Men and What Followed

Charles Sweeney retired from the Air Force as a Major General. He wrote about the mission in his memoir War’s End and died in 2004. He said in later years that he understood the weight of what had happened at Nagasaki and never claimed he would have done anything differently. His job was to bring his crew home. He did.

Kermit Beahan, the bombardier who found that break in the clouds, died in 1989. Frederick Bock, whose name the aircraft bore, was flying a different airplane that day - he watched the mission from a distance.

Japan’s formal surrender was signed on September 2, 1945, aboard the USS Missouri in Tokyo Bay.

Key Takeaways

The Bockscar mission launched with a crippling mechanical defect: a dead fuel pump left 800 gallons permanently inaccessible, shrinking the flight’s margin to near zero before it left the ground.
A 45-minute rendezvous wait - three times the protocol maximum - burned reserves Sweeney couldn’t afford and was caused by a simple altitude miscommunication.
Three passes over Kokura Arsenal produced no visual confirmation; smoke from the previous night’s Yahata firebombing shielded the primary target, a coincidence now known in Japan as “the luck of Kokura.”
Two of Bockscar’s four engines ran dry while still taxiing after an emergency landing at Okinawa’s Yontan Airfield - an airfield that had no advance warning of their arrival.
The original Bockscar is on free public display at the National Museum of the United States Air Force, Wright-Patterson AFB, Dayton, Ohio.