Nadezhda Popova, a Soviet aviator who became one of the most celebrated of the so-called “Night Witches,” female military pilots who terrorized the Nazi enemy with their nocturnal air raids during World War II, died July 8. She was 91.

Her death was reported by the London Daily Telegraph. The place and cause could not immediately be confirmed. In a statement, Ukrainian President Viktor Yanukovych called Ms. Popova’s life “an example of selfless service to Motherland.” Her “feats in the course of the Great Patriotic War,” he said, “will never be forgotten.”

Ms. Popova was among the first female pilots to volunteer for service in the Soviet military during World War II and became a squadron commander in her swashbuckling all-female regiment. She flew 852 combat missions — including 18 during one night — and was honored as a Hero of the Soviet Union, one of the nation’s highest decorations.

Like American women in the age of Amelia Earhart, many Soviet women had become enchanted with aviation in the 1930s. They were initially rejected for combat service during World War II, but Soviet leader Joseph Stalin thought better of the decision in 1941, when Germany broke the Soviet-German nonaggression pact and invaded.

Led by Marina Raskova, a renowned aviator who would later die in a plane crash, three women’s regiments were born of necessity. While other nations employed female pilots largely in support roles, the Soviets dispatched their female aviators on delivery and reconnaissance missions, as well as daring raids to take out enemy targets. Treated in many respects like their male colleagues, the women did, however, receive larger soap rations.

Nadezhda Popova (Courtesy of Albert Axell)

Ms. Popova served with the night bombers, perhaps the most feared of the three women’s regiments. Their planes, rickety two-seaters made of plywood and canvas, were jerry-rigged as bombers.

The pilots achieved a degree of surprise by shutting down their engines in the last stages of their bomb runs; the Germans heard only the hiss of the air flowing across their wings and, likening the sound to that of a broomstick in flight, referred to the women as Night Witches.

“The Germans spread stories that we were given special injections and pills which gave us a feline’s perfect vision at night,” Ms. Popova told Albert Axell, a historian, in an interview for his book “Greatest Russian War Stories, 1941-1945.” “This was nonsense, of course,” she continued. “What we did have were clever, educated, very talented girls.”

They women generally ranged in age from 17 to 26. Ms. Popova was 19 when she joined the pilots and became “one of the best, and one of the luckiest,” according to the Moscow Times.

“When the wind was strong it would toss the plane. In winter when you’d look out to see your target better, you got frostbite, our feet froze in our boots, but we carried on flying,” she said. “If you give up nothing is done and you are not a hero. Those who gave in were gunned down and they were burned alive in their craft as they had no parachutes.”

Once, she watched four planes crash, carrying eight women to their deaths. “What a nightmare,” she said decades later, “poor girls, my friends, only yesterday we had slept in the bunks together.”

Ms. Popova remarked that perhaps she was born lucky. One time, she counted 42 bullet holes in her plane. “Katya, my dear,” she said to her navigator, “we will live long.”

Nadezhda Vasiliyevna Popova was born Dec. 17, 1921, in what is now Dolgoye, Ukraine, according to the Daily Telegraph. She planned to become a teacher or a doctor, until one day a plane landed near her home and she met the pilot.

“I had thought only gods could fly,” she said in an account published in the book “A Dance With Death: Soviet Airwomen in World War II,” by Anne Noggle. “It was amazing to me that a simple man could get in a plane and fly away.”

Ms. Popova joined a flying club and later graduated from an aviation school. When the war started, she was working as an instructor. She said that she decided to join the military after losing her brother in the war and after watching Germans abuse her townspeople.

“I saw the German aircraft flying along our roads filled with people who were leaving their homes, firing at them with their machine guns,” she said. “Seeing this gave me feelings inside that made me want to fight them.”

Over the course of the war, Ms. Popova said, she fought in Belorussia, Poland and Germany. In 1942, she was shot down in the North Caucasus. Retreating with the infantry, she met her future husband, Semyon Kharlamov, also a decorated pilot. They were married for many years until his death; together they had a son, who grew up to be a general in the Belarusian air force. A complete list of survivors could not be determined.

Minerva, an academic publication on women and the military, cited Soviet records indicating that the women’s regiments flew more than 30,000 combat sorties. Their ranks produced at least 30 Heroes of the Soviet Union — about a third of all women so honored — and at least three fighter aces.

Decades after the war, Ms. Popova, who often was called Nadya, reflected on the perils she had endured. “At night sometimes, I look up into the dark sky, close my eyes and picture myself as a girl at the controls of my bomber,” she said, “and I think, ‘Nadya, how on earth did you do it?’ ”