Second Lieutenant Nguyễn Văn Cử had personal reasons to resent the Diệm regime. His father, Nguyễn Văn Lực, was a leader of the VNQDD — the Vietnamese Nationalist Party — and in 1960 Diệm had jailed the elder Nguyễn for a month for "anti-government activities." The VNQDD planned the operation: Cử and First Lieutenant Phạm Phú Quốc, a pilot from the same squadron, would strike the Independence Palace on February 27. Quốc had subordinates he might have recruited, but doubted their loyalty and chose not to risk it. The plan was simple in concept and audacious in execution — two pilots in A-1 Skyraiders turning their own weapons against the presidential residence in broad daylight, hoping that a single decisive blow would expose Diệm's vulnerability and trigger a general uprising.

The attack lasted half an hour. The pilots carried enough ordnance to level the palace, but did not expend all their munitions. When the first bomb failed to detonate, Diệm had time to flee to a cellar in the eastern wing, where he was joined by his elder brother Archbishop Ngô Đình Thục, his younger brother Ngô Đình Nhu, and Nhu's wife Madame Nhu, who fractured her arm while running for shelter. Their children huddled with them underground as the building shook. Three palace servants and guards died. About thirty more staff were injured. Outside the grounds, an American contractor fell to his death from a rooftop where he had been watching the spectacle. Quốc's aircraft took fire from a minesweeper on the Saigon River, forcing him to eject and land in Nhà Bè, where he was arrested. Cử escaped to Cambodia. Most of Saigon's inhabitants, remarkably, went about their usual business, indifferent to the explosions echoing across the city.

Diệm emerged from the cellar claiming "divine" protection — the unexploded bomb in his reading room serving, in his mind, as proof of providential favor. But the attack's real effect was to accelerate his worst instincts. He ordered all South Vietnamese air force aircraft grounded and combat missions suspended while security officials investigated pilots for anti-regime sympathies. Tanks were placed on the runway at Bien Hoa Air Base. Without fighter escort, American helicopter operations against the Viet Cong in the surrounding jungles were deemed too dangerous, and for three days the air war effectively stopped. The National Revolutionary Movement, the Ngô family's instrument for staging mass demonstrations, demanded the death penalty for both pilots and urged "the strictest measures to insure discipline in the military." Diệm complied with the spirit of the demand: press freedom was curtailed, political associations restricted, and the circle of trust around the president shrank further.

In his first meeting with U.S. Ambassador Frederick Nolting after the bombing, Diệm insisted that the American media was responsible for the attack. He pointed to a recent Newsweek article and other "derogatory" press coverage, arguing that "the Americans were supporting the revolution." The logic was circular but revealing: any criticism of the regime became evidence of foreign conspiracy, which justified further repression, which generated more criticism. In a later, more candid moment with General Paul D. Harkins, Diệm made a remark that now reads as prophecy: "I shouldn't have put him in the air force, because I had put his father in jail years ago." He added, quietly, "Sometime I'm going to get shot right in the back of the neck. Sometime they'll get me that way." Twenty months later, on November 2, 1963, Diệm and his brother Nhu were overthrown in a coup and shot dead.

The aftermath divided the conspirators sharply. Cử fled to Cambodia, where Prince Sihanouk — who routinely granted asylum to those who had tried to depose or assassinate Diệm — allowed him to stay. He took up work as a language teacher, trading a cockpit for a classroom. Quốc went to prison, but his story took a stranger turn: after Diệm's overthrow, Quốc was released and returned to military service. He advanced to the rank of lieutenant colonel in just eighteen months. On April 20, 1965, he was killed in an air raid over North Vietnam, dying in the kind of combat mission his attack on the palace had been meant to make possible. Meanwhile, Diệm's police hunted for Cử's father, who had gone into hiding after the bombing. The palace itself, too damaged to repair, was demolished and replaced by the Reunification Palace that stands in Ho Chi Minh City today — a building whose very existence is a monument to the one that two pilots tried to bring down.