Johnny Johnson, the Last World War II ‘Dambuster,’ Dies at 101

In the hours before dawn on May 17, 1943, airmen from Britain and its commonwealth carried out an audacious low-level raid on Germany’s industrial heartland, the Ruhr region. They dropped specially designed bombs that breached two major dams and damaged another, creating massive floods in a dramatic strike against the Nazi war machine. The torrent destroyed war plants, power stations, bridges, railroads and roads; devastated farmland; and washed away towns.

The 133 men aboard the raid’s 19 Lancaster heavy bombers were members of the Royal Air Force’s 617 Squadron. But they would soon be known as the Dambusters, for a mission that became a storied chapter of British air power in World War II.

The devastation from the floodwaters forced Germany to divert thousands of troops to the repair efforts over the months that followed and provided a huge boost to British morale. But it also brought the deaths of an estimated 1,200 to 1,600 people trapped by the flooding, a majority of them slave laborers and prisoners of war unable to escape their confinement.

Eight of the bombers were either shot down or lost in accidents, resulting in the deaths of 53 crewmen and the capture of three others.

When George Johnson, an Englishman known as Johnny, died on Wednesday night in a care home in the Bristol area of southwest England, he was remembered as the last surviving airman of the Dambuster raid. He was 101.

His death, announced by his family on Facebook, came five years after Queen Elizabeth II conveyed the title Member of the Order of the British Empire on Mr. Johnson in a ceremony at Buckingham Palace.

The honor was bestowed after thousands had signed a petition asking that Mr. Johnson, a bomb-aimer during the war (the equivalent of an American bombardier), be accorded recognition in his final years as a collective tribute to the Dambusters.

George Leonard Johnson was born on Nov. 25, 1921, in the East Midlands village of Hameringham, the youngest of six children of Charles and Mary Ellen (Henfrey) Johnson. His father was a farmer; his mother died when George was 3.

He entered an agricultural school at age 11, graduated in 1939 and joined the Royal Air Force in 1940.

After flying some 50 missions over Europe, Mr. Johnson, a sergeant, was assigned to the 617 Squadron, a secret unit created only two months before the Dambuster raid.

Braving antiaircraft fire, the squadron, based at Scampton, north of London, breached Germany’s Eder and Möhne dams and damaged the Sorpe Dam in what was formally known as Operation Chastise.

Since the dams were considered too narrow to be pinpointed from the air, especially at night, the planes carried innovative “bouncing bombs” — essentially underwater mines — designed for the raid by a British engineer named Barnes Wallis.

In the attacks on the Möhne and Eder dams, from a height of about 60 feet, the bombs were dropped into reservoirs several hundred yards from the dams, then bounced along the water’s surface to avoid anti-submarine nets. Upon reaching the walls, they descended underwater to a prescribed depth. Set off by a timer, they blew huge holes in the dams, allowing billions of tons of water to tear through them.

The crew of Sergeant Johnson’s plane — flown by the lone American on the raid, Flight Lt. Joe McCarthy, a native of Long Island who had joined the Royal Canadian Air Force — had an even tougher task

Its target, the Sorpe Dam, was an embankment lined with soil and rocks that was expected to absorb much of a bomb’s explosive power, in contrast to the two more vulnerable masonry dams.

“It was misty on the way out, but we did find the Sorpe,” Mr. Johnson recalled in his memoir, “The Last British Dambuster” (2014). “In the totally clear moonlight, it was an incredible sight.”

Lieutenant McCarthy had to clear the steeple of a church, then dip to a level of 30 feet and fly parallel and extraordinarily close to the wall for his plane’s bomb to make a significant impact when it exploded underwater. He made repeated runs along the dam before Sergeant Johnson was satisfied that he could drop his bomb at the center point, where it could do the most damage.

“I found out very quickly how to be the most unpopular member of the crew,” Mr. Johnson recalled in a 2013 interview with the University of Huddersfield in England, explaining that his patience had increased the chances of his plane being spotted by the Germans.

At one point, he said, his rear gunner pleaded, “Will somebody just get that bomb out of here?”

“After nine dummy runs, we were satisfied we were on the right track,” Mr. Johnson wrote in his memoir. “I pushed the button and called, ‘Bomb gone!’ From the rear of the plane was heard ‘Thank Christ for that!’ The explosion threw up a fountain of water up to about 1,000 feet.”

The bomb, which detonated at a water depth of 25 to 30 feet, damaged the dam but did not breach it. Seconds later, Lieutenant McCarthy had to pull up in order to avoid crashing into a hill. One other Lancaster hit the dam, but its bomb caused only minor damage as well.

Two days after the raid, Prime Minister Winston Churchill hailed it in a speech to a joint session of Congress. King George VI and his wife, Queen Elizabeth (later the Queen Mother), visited the airmen at their base in late May to offer congratulations.

The squadron leader, Wing Commander Guy Gibson, who would be killed in action later in the war, received the Victoria Cross, Britain’s highest award for valor. Sergeant Johnson was awarded the Distinguished Flying Medal.

The raid was recounted in the 1955 British film “The Dam Busters,” starring Richard Todd as Commander Gibson and Michael Redgrave as Mr. Wallis. It was based in part on Paul Brickhill’s 1951 book of the same title.

Mr. Johnson retired from the Royal Air Force in 1962 and became a teacher. He spoke to schoolchildren in his later years about the Dambusters’ exploits.

His wife, Gwyn (Morgan) Johnson, died in 2005. Information on his survivors was not immediately available.

For all the harrowing missions he took part in, Mr. Johnson said, he felt confident that he would survive.

“I didn’t feel afraid,” he told James Holland for his book “Dam Busters” (2012), in recalling his combat service between 1942 and 1944. “I was sure I was going to come back every time.”