On 2 January 1967, U.S. Air Force F-4 Phantom II multirole fighters flew a mission along flight paths typically used by the bombers during Rolling Thunder.

The ruse drew an attack by Vietnamese Mikoyan-Gurevich MiG-21 interceptors, whose pilots expected to find heavily loaded fighter-bombers.

However, the Phantom suffered from a lack of maneuverability, as its original conception as a fleet defense interceptor dictated that air combat would occur at beyond visual range with radar-guided missiles.

The F-4's primary adversary during this engagement was the Soviet-built Mikoyan-Gurevich MiG-21, NATO reporting name 'Fishbed', a small fighter designed as a short-range interceptor, a role that perfectly suited its use by the VPAF.

Armed with two Vympel K-13 missiles (known to US pilots by their NATO designation "Atoll"), the MiG-21 had rapid acceleration, was agile at supersonic speeds and at high altitudes, and significantly outperformed its primary target – the F-105 Thunderchief – in all flight regimes.

Scoring its first kill on 5 October 1966,[4] in December intercepting MiG-21s shot down two F-105s and forced 20% of all strike sorties to jettison their bombloads.

[3] The agility of the MiG-21 and the VPAF tactic of high-speed slashing attacks from astern under GCI control posed a challenge to American pilots, who had become predictable by staging large formation strikes from Thailand flying roughly the same routes and times of day allowing the VPAF to challenge them with a relatively small force of 15 or 16 MiG-21 fighters used as point defense interceptors.

[5] MiG interceptions had consequently increased, primarily due to MiG-21s using high-speed hit-and-run tactics against bomb-laden F-105 formations, and although only two bombers had been lost, the threat to the force was perceived as serious.

Bombing of North Vietnamese airfields was still forbidden at the start of 1967, and 8th TFW wing commander Colonel Robin Olds proposed an aerial ambush as the best means of mitigating the threat.

His idea for Operation Bolo was relatively simple: Make the agile Phantom II look like the cumbersome bomb-laden F-105 and lure the MiGs into a sustained dogfight that depleted the MiG-21s of their relatively small fuel load and flight time.

The planners determined that if the MiGs reacted, their fuel endurance from takeoff to landing would extend to a maximum of 55 minutes.

Momyer approved the plan, which was assigned the code name "Bolo", after the cane-cutting machete which doubled as a Filipino martial arts weapon.

This was the intent of the plan — to draw the MiGs into the Phantoms' killing zone and strike while the North Vietnamese were still expecting to find the less-dangerous F-105s.

Col. Olds also charged his maintenance crews with inspecting, cleaning, and repairing all equipment on the aircraft assigned to the mission, a task that took several days.

The mission launched from Ubon that afternoon after another hour's delay, and Olds, leading the first flight, arrived over Phúc Yên Air Base at 1500 local time.

Flying southeast on the ingress route used by F-105s, the mission drew no defensive reaction, and Olds found that a floor of thick clouds blanketed the area below, concealing any view of MiGs taking off.

[10] Unknown to Olds, the North Vietnamese GCI controllers had delayed takeoffs by approximately 15 minutes because of the overcast.

Olds' flight immediately dropped fuel tanks and lit afterburners to engage three MiGs that, although apparently emerging at random, actually had been directed to have the first appear at the flight's "six" (rear) and the next two moments later at its "ten" (left front), presenting one MiG with a tail-shooting solution and tactical surprise.

[12]The vertical maneuver, known as a "vector roll," positioned his Phantom above the tighter-turning MiG-21, then when it completed its turn, Olds dropped in behind it and fired two AIM-9 Sidewinder missiles.

When Rambler entered the engagement, Stone spotted a pair of MiGs popping up through a break in the clouds, dove and launched an AIM-7 Sparrow, which failed to ignite.

A little bit after completing a turn to the northwest, we identified a patrol of four MiG-21s in spread formation at a distance of 5 miles –about 8 km- at '2 o'clock' and below us.

I decided to follow the Navy pilots' tactics - at close range foregoing the radar tracking, but looking through the reticle instead.

[12]Seconds later, another MiG-21 crossed in front of Rambler 02 and was apparently destroyed by a Sparrow fired by its pilot, Lawrence Glynn.

The final four flights of 8th TFW aircraft arrived to find the engagement over and departed the area because of the SAM threat, while the Da Nang-based East Force assessed the weather conditions and did not penetrate North Vietnamese airspace.

Two of the Ubon-based West Force had aborted the mission for maintenance problems, and ultimately only 26 of the 56 assigned fighters entered the target area, and only 12 of those engaged.

The following table summarizes the 8th TFW's seven MiG-21 victories:[12] A North Vietnamese source confirms the loss of only five MiG-21 during Operation Bolo and states that all five pilots bailed out safely:[14] As the F-4s landed at Ubon, their ground crews lined the taxiway.

Of the 16 MiG-21s known to be in the VPAF inventory, 11 to 14 had been engaged on that day (depending on the source), with seven destroyed and two others probably shot down (by Combies and Maj. Herman L. Knapp, Rambler 03).

Years later, Vietnamese government sources admitted that Operation Bolo on 2 January was one of the worst days for the VPAF during the war.

On both 5 and 6 January, a pair of 555th TFS F-4C Phantoms, flying a close formation to appear as a single target on North Vietnamese radar, flew the high-speed profile.

Richard M. Pascoe and 1st Lt. Norman E. Wells) and Crab 02 (Maj. Thomas M. Hirsch and 1st Lt. Roger J. Strasswimmer) each scoring a kill.