Piloting a MiG-17F while assigned to the 923rd Fighter Regiment, Bay claimed 7 aerial combat victories while engaged against aircraft of the USAF and USN: 2 F-8s, 1 F-4B, 1 A-4C and 1 F-105D.

Of 16 VPAF (North Vietnamese) aces during Vietnam War, only Bay, Luu Huy Chao, and Le Hai solely flew MiG-17s.

Nguyen Van Bay was born in 1937 in a place nowadays Sa Đéc City, Đồng Tháp Province.

Bay returned to Vietnam for combat duty with the 921st Fighter Regiment, but scored his first aerial victory with the 923rd Fighter Regiment in April 1966 during the early part of the U.S.-involved Vietnam War; Bay was awarded the coveted Hero of the Vietnamese People's Armed Forces medal on 1 January 1967.

[3] Note: The following aerial engagements do not match with the number of aircraft he shot down, according to the United States Air Force.

Nevertheless, the following aerial-combat victories listed, at the very least, include all the kills acknowledged and credited to Nguyễn Văn Bảy by the VPAF: Bay had his first engagement when he was attacked by an F-4 Phantom.

"[4] USAF F-4C Phantom IIs participated in a strike along Route 10 at Bac Son-Binh Gia, and a flight of four MiG-17s that included pilot Nguyen Van Bay were directed by North Vietnamese ground control intercept radar (GCI) to fly at 2,500 meters and 15 km south of Bac Son-Binh Gia; due to the constant shifting of direction of flight by the U.S. aircraft, the MiG-17 pilots decided engaged the American raiders head-on, and in the ensuing melee, Luu Huy Chao claimed a Phantom shot-down, while Nguyen Van Bay scored hits on another Phantom, damaging it for certain, but couldn't confirm it as a kill.

[5] On 29 April 1966, North Vietnamese GCI directed the 923rd Fighter Regiment MiGs into two separate battles against USAF and USN aircraft.

[5] In the other interception flight of the 923rd regiment MiG-17s that day, Nguyen Van Bay intercepted USAF F-105s and F-4s, shooting down the F-105D Thunderchief piloted by Lt. Donald W. Bruch of the 333rd TFS, just north of Hanoi, although the US-side claims this loss was due to AAA; Lt. Bruch according to witnesses, was not seen to eject from his stricken aircraft, and was declared KIA on 4 May 1966.

[9] Le Thanh Chon, the senior control officer at Gia Lam airfield, vectored Bay and his wing-man Vo Van Man to an unknown target in the South.

As his rounds struck near the canopy of the F-8, the plane began coming apart, Crusader pieces filled the air as Bay's MiG started to fly through them.

The American F-8 pilot was captured shortly after ejecting, and turned out to be Wilfred K. Abbott, serving in the squadron VF-111, carrier USS Oriskany.

In the early afternoon at Gia Lam airfield, Bay was flying in the number three position in a flight of four, when they were directed to engage US aircraft.

Bay and his flight commenced to cut off the F-4s, he rolled in behind the F-4C piloted by Major John "Robbie" Robertson and his backseater Hubert Buchanan (USAF # 63–7643, 555th TFS).

[10] On this date, Bay was flying the lead of a four-ship flight, when he was directed to a target 10 miles ahead by ground control.

Bay, now alone, and with his fuel becoming low, found himself dodging multiple missiles from US aircraft;however, they began to depart North Vietnam's air space.

Just minutes after takeoff, Nguyen Van Bay made visual contact with an incoming flight of 20 F-105s and 4 F-4 Phantoms from 10 km away.

At this point in time, the U.S. Thunderchiefs and Phantom crews also made visual contact with the VPAF MiGs, and were forced to jettison their bomb loads; the F-4s attacked the MiGs first, without success Ho Van Quy quickly approached a flight of F-105 with an advantageous shooting position at only 500–600 meters from his target F-105, but failed to score a hit.

Bay was then able to maneuver himself into a good shooting position against the crew of the USN F-4B (BuNo 153000) from VF-114, USS Kitty Hawk (CVA-63) piloted by Lcdr.

Laing believed that they had been "shot down by AAA" according to some sources, while "running out of fuel" according to others (the North Korean squadron Doan Z claimed an "F-4 shot-down", however the only other loss from U.S. carrier aircraft that day was an A-6A Intruder (BuNo 152589) of VF-85, also from the USS Kitty Hawk, of which the U.S. claims to have been shot-down by AAA; both Lt(jg) L.I.

Bay was awarded the Hero's Medal of the Vietnamese People's Army for his outstanding skill and bravery in combat, and for his superb leadership of his flight.

[17] In the afternoon of this day, Nguyen Van Bay was among a flight of MiG-17s flying out of Hoa Lac on a heading of 120-degrees over to Hoa Binh, where he made visual contact of F-4 Phantoms from 8 km out, and engaging them in three-minutes time from the initial visual identification; he would quickly shoot-down one of the four USAF F-4Cs from the 389th TFS, piloted by Lt. L.H.

On April 19, 1972, the two men from the 923rd Fighter Regiment flew their MiG-17s, each armed with two 250 kg bombs, towards the open sea in what was known as the Battle of Đồng Hới[22] Le Xuan Di headed his aircraft for the US destroyer USS Higbee, whilst Nguyen Van Bay struck for the US Navy light cruiser USS Oklahoma City, which had been shelling targets in Vinh City.

[24] This was the first successful air strike made by an enemy jet fighter bomber on a US Navy warship while actively engaged in combat.

As is often the practice in many countries, high ranking "Aces" are often grounded during a continuing war, to utilize their attained status to inspire future generations.