Two Grumman F6F Hellcats streaked across the sky above the Philippines. Below them, armadas of ships clashed in an epic battle to control the sea around the island of Luzon, where American and Australian ground forces engaged the Japanese in bitter combat.

It was October 24, 1944, and the Battle of Leyte Gulf—the largest naval engagement in modern history—had just begun. The Hellcat pilots, U.S. Navy Capt. David McCampbell and his wingman Ens. Roy Rushing, were looking for trouble up ahead and they found it—a squadron of 60 Japanese aircraft, including bombers escorted by Zeroes, the feared fighter of the Japanese Imperial Navy.

Despite being overwhelmingly outnumbered, the American pilots never hesitated. Throttling their Hellcats’ powerful 2,000-horsepower engines, they ascended for the attack. From on high, they waded into the enemy on repeated sorties, each blasting away with six .50-caliber machine guns.

“We’d make an attack, keep our altitude advantage and speed, and go down again,” McCampbell recalled in a 1987 interview for the U.S. Naval Institute’s oral history project. “We repeated this over and over till we made about 20 coordinated attacks.”

The American pilots shot down a total of 15 planes—an achievement still unequalled in combat aviation. Both earned “ace in a day” status by downing five or more aircraft each on one mission. That day, McCampbell scored nine “kills”—seven Zeroes, also known as the Mitsubishi A6M Reisin, and two “Oscars,” the Nakajima Ki-43. None of the Japanese bombers reached their targets. With their formation so scattered, the enemy pilots had to abort their mission.

McCampbell and Rushing were aided in their accomplishments by the aircraft they flew, the Hellcat F6F. The rugged and versatile fighter plane became the bulwark of the U.S. Navy and Marine Corps for carrier-based attacks in the Pacific theater during World War II. Nicknamed the “Zero Killer,” the American Hellcat, time and again, stayed one step ahead of Japan’s main fighter.

“The Grumman Hellcat outperformed the Zero in nearly every major category,” says Thomas Paone, curator at the Smithsonian’s National Air and Space Museum. “While it wasn’t the fastest aircraft, it was certainly faster than the Zero. The F6F could fly higher and deliver more firepower than the Japanese plane, making it the superior aircraft in the Pacific.”

The National Air and Space Museum includes a Grumman F6F Hellcat in its collections. Suspended from the ceiling at the museum’s Udvar-Hazy Center, located in Chantilly, Virginia, this particular model saw service in World War II as part of Fighter Squadron 15 aboard the aircraft carrier USS Hornet, though it never participated in combat. It was donated to the Smithsonian by the U.S. Navy in 1948 and in 1983, the artifact underwent a full restoration.

Ironically, this storied fighter plane was pretty much an afterthought. The F6F was intended as an improved version of another a rugged American fighter, the F4F Wildcat that had certain limitations when facing the Zero. The Hellcat, however, was only developed after the F4U Corsair, the Wildcat’s replacement, encountered development difficulties.

Grumman built the heavily armored Hellcat based on the F4F design but with different landing gear, much larger wings, and a bigger engine and propeller—essentially a brand-new fighter. It launched into production quickly in 1943 with Grumman manufacturing 12,275 planes by the end of the war.

“It was a simple aircraft to build, a simple aircraft to fly and it was very rugged,” Paone says. “Just having newly trained pilots being able to fly it well was a major factor in its success.”

The Hellcat proved to be a dream fighter in nearly every way. Pilots loved it because of its outstanding performance against the Zero and other Japanese planes. Despite entering the war when it was halfway through, the Hellcat accounted for 75 percent of all aerial victories recorded by the Navy in the Pacific, according to the National Naval Aviation Museum.

The adaptable aircraft enabled McCampbell and Rushing to make history. For McCampbell, this was the second time he achieved that honor. The ace had previously shot down seven Japanese aircraft on June 19, 1944 during the Battle of the Philippine Sea, in what became known as the Marianas Turkey Shoot.

As the Battle of Leyte Gulf got underway on October 24, 1944, McCampbell scrambled from the USS Essex. But he would soon learn his aircraft was severely handicapped.

As he and Rushing hurriedly made their way into the air, McCampbell noticed his main tank was only half full. He continued to shoot down enemy aircraft until he realized his Hellcat fuel tanks were nearly empty and he might not make it back to the aircraft carrier.

Fortunately, McCampbell did manage to land his Hellcat back on the Essex, but air crews could not restart the aircraft to move it—the tanks were bone dry. Worse, when they examined his machine guns, they found he had only six bullets left and all were jammed.

“But it worked out all right,” he said simply in the oral history project interview.

For their bravery that day, McCampbell, who died in 1996, received the Medal of Honor while Rushing, who died in 1986, got the Navy Cross. McCampbell, who remains the U.S. Navy’s all-time top fighter ace, also earned the Navy Cross, Silver Star, Legion of Merit and three Distinguished Flying Crosses. With 34 aerial victories, he was the third highest scoring American ace, but the highest scoring U.S. fighter pilot to survive the war.