Operation Bolo was a offensive counter-air (OCA) mission, conducted by the United States Air Force, fought over the Democratic Republic of Vietnam on January 2, 1967, during the Vietnam War, and in the context of the United States Air Force component of the Operation ROLLING THUNDER aerial bombardment campaign. It is has become a classic example of the fighter sweep.
Bolo pitted the new American F-4 Phantom II multirole fighter against its rival, the Soviet MiG-21 (NATO reporting name FISHBED) interceptor. Operation Bolo, considered to be one of the most successful combat ruses of all time, prompted North Vietnamese pilots and strategists, as well as Soviet tacticians, to reevaluate their employment of the MiG-21.
USAF aircraft used against North Vietnam
In 1967, the USAF had been using the F-4 Phantom II aircraft in both air superiority and fighter-bomber roles, as the other major tactical aircraft used by the Air Force to attack North Vietnam, the F-105, lacked the maneuverability for effective air-to-air combat, although it was a good strike aircraft.
While more maneuverable, the F-4 had two critical armament problems. The early versions did not have an internal autocannon for dogfighting. They had been built with the assumption that air-to-air missiles would be adequate for the original Navy role of fleet air defense. Unfortunately, while the AIM-9 Sidewinder was a fairly reliable short-range, heat-seeking missile, the longer-range AIM-7 Sparrow suffered from both poor reliability, and rules of engagement that precluded its advantage for beyond visual range (BVR) engagement.
North Vietnamese defensive fighters
The F-4’s primary adversary during this engagement was the Soviet-built 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 (missile) (NATO reporting name 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 (officially named the Thunderchief but routinely called the Thud) - in all flight regimes.
A small, light fighter, its low wing loadings were excellent for air combat maneuvering and its small size made it difficult to spot even when its adversary was warned of its presence. In contrast, the F-4 and F-105 were large aircraft, and, at the time, the F-4 engines tended to produce very noticeable smoke trails.
Typically, the MiG-21 was used in hit-and-run tactics; being vectored by Ground Controlled Intercept (GCI) to an intercept position to the vulnerable rear of an American strike formation, then executing a missile attack and diving away before fighter cover could intervene. Scoring its first kill in October 1966, in December intercepting MiG-21s shot down two F-105s and forced 20% of all strike sorties to jettison their bombloads. At the time of Operation Bolo, the VPAF had 16 MiG-21's in its inventory.
The agility of the MiG-21 and the Vietnam People's Air Force tactic of high-speed slashing attacks from astern under GCI control posed a significant 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 MiG-21 fighters used as point defense interceptors. They were ideal short-range interceptors for fighting larger aircraft that were limited in their dogfighting ability.
"Operation Bolo" was created to deal with the new MiG threat. Since October the F-105s had been equipped with radar jamming pods that had virtually ended their own losses to surface-to-air missiles, but had shifted SAM attacks to the Phantoms, unprotected because of a shortage of the pods. Rules of engagement that had previously permitted the F-4 MiGCAP to escort the F-105s in and out of the target area had been revised in December to limit MiGCAP penetration to the edge of SAM coverage. 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 Col. Robin Olds proposed an aerial ambush as the best means of mitigating the threat.
Colonel Robin Olds was the commander of the 8th Tactical Fighter Wing and an experienced fighter pilot who had become an double ace in two tours over Europe during World War II. He was sent to Southeast Asia to revive the performance of the 8th TFW and he did so from the cockpit. Five days after he arrived at Ubon, the 8th TFW lost an F-4C to an air-to-air missile shot from a MiG-21, the first such loss in the war. Considering also two other F-4 losses to MiGs in the two weeks preceding his taking command, Olds was upset by the sudden negative trend (only two USAF Phantoms had been shot down by MiGs previously, the most recent in April 1966), but was also convinced that his pilots could take on the MiG-21 and prevail if the MiGs could be drawn into the air on even terms. His idea for Operation Bolo was relatively simple: substitute Phantoms armed with air-to-air missiles for the bomb-laden F-105 strike aircraft and lure the MiGs into a dogfight.
Planning Operation Bolo
Olds assigned the planning of Operation Bolo to a quartet of creative junior officers in his wing: the wing tactics officer Capt. John B. Stone, 1st Lt. Joseph Hicks, 1st Lt. Ralph F. Wetterhahn, and Maj. James D. Covington. Working under the tightest security, the pilots assigned to fly the mission would not be briefed until December 30th.
The group planned for a coordinated mission by a "west force" of seven flights of F-4Cs from the 8th TFW at Ubon and an "east force" of seven flights of F-4Cs from the 366th Tactical Fighter Wing based at Da Nang Air Base, South Vietnam. The west force would simulate the F-105 strike force while the east force would cover alternate airfields and provide a barrier against MiGs attempting to flee to China. The task force also included 6 flights of F-105s for protection from SAMs, airborne radar support by College Eye EC-121 aircraft, and radar jamming support by EB-66s, escorted by four flights of F-104s of the 435th TFS at Ubon.
The planners determined that if the MiGs reacted, their fuel endurance from takeoff to landing would extend to a maximum of 55 minutes. Arrival times of the F-4 flights over the targeted airfields were set five minutes apart to ensure maximum time for engagement and to attempt to run surviving MiGs out of fuel. The mission was also planned so that no other US aircraft would be present, allowing the first three flights of F-4s "missile-free" engagement without having to first identify the target.
In other words, knowing that any aircraft coming at these flights was an enemy, their Rules of Engagement were changed to let them use the beyond visual range (BVR) AIM-7 Sparrow capability without, as was usually required, getting visual identification of the target.
Everything hinged on getting the MiGs airborne; if they didn't take the bait, then the plan would not come to fruition. In order to deceive the North Vietnamese, the west force had to fly the same ingress routes, altitudes, and speeds as the F-105, use the same air refueling tanker tracks and altitudes, and use F-105 jargon on the radio. (However, to Olds' dismay, the flights were still assigned callsigns of MiGCAPs throughout the war, which were the names of American-made automobiles: Olds, Ford, Rambler, Lincoln, Tempest, Plymouth, and Vespa.) The F-4s were fitted out with the QRC-160 jamming pods normally carried only by F-105s, so that their electronic signature would be the same, and the F-4s would also fly the inflexible line-abreast pod formations used by the F-105s to maximize pod effectiveness. The pods had to be mounted on one of the fuel tank wing pylons, forcing the F-4s to carry a centerline and single wing tank, creating an asymmetric imbalance that made takeoffs difficult (the aircraft would try to roll on liftoff to the side carrying the wing tank).
The operation plan was presented to Gen. William Momyer, commanding the Seventh Air Force, on December 22, 1966. Momyer approved the plan, which was assigned the code name "Bolo", after the cane-cutting machete which doubled as a Filipino martial arts weapon. Sharp and deadly, the Filipino bolo does not appear to be a weapon until the opponent is drawn in too close to evade. 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. As soon as the F-4s were equipped with the AN/QRC-160 electronic countermeasures pod, the date of the attack was set for January 1, 1967.
Executing the mission
Weather delayed the start of the mission. It eventually launched from Ubon that afternoon after another hour's delay, and Olds, leading the first flight, arrived over Phuc Yen airfield 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. Unknown to Olds, the North Vietnamese GCI controllers had delayed takeoffs by approximately 15 minutes because of the overcast. He reversed course and flew to the northwest. When three minutes had passed without contact, and with Ford flight almost in the area, he canceled the missile-free option. Just as Ford flight arrived in the target area, the first MiGs emerged from the clouds below.
The first attack came as the second flight of F-4s was also entering the area. 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. All three flights that engaged MiGs later reporting encountering this tactic.
Olds 02, flown by mission planner Ralph Wetterhahn, scored the first kill by shooting the MiG with an AIM-9 Sidewinder as Olds 01, flown by Col. Olds, fired three missiles that failed either to launch or guide. Olds explained that the FISHBEDs indeed started to appear, although cloud cover interfered with visual spotting. Olds avoided the first MiG-21 he saw, since it was better positioned for his wingman to engage. Eventually, he found a valid target.
[It] ...Ain my ‘10 o’clock’, from the right to the left: in simple words, almost in the opposite direction. The first MiG zoomed away and I engaged the afterburner to get in an attack position against this new enemy. I reared up my aircraft in a 45 degree angle, inside his turn. He was turning to the left, so I pulled the stick and barrel-rolled to the right. Thanks to this maneuver, I found myself above him, half upside down. I held it until the MiG finished his turn, calculating the time so that, if I could keep on turning behind him, I would get on his tail, with a deflection angle of 20 degrees, at a distance of 1,500 yards. That was exactly what happened. He never saw me. Behind and lower than him, I could clearly see his silhouette against the sun when I launched two Sidewinders. One of them impacted and tore apart his right wing.
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. One struck the MiG's right wing and tore it off. The MiG went into a spiral and disappeared into the clouds below, the second kill of the battle. At nearly the same time, Olds 04, flown by Capt. Walter S. Radeker III, spotted a MiG tracking his element lead and maneuvered to engage it. Radeker was unable get a consistently good tone (which would indicate missile lock), but launched. His Sidewinder guided perfectly, however, and struck the MiG just in front of its tail, sending it into a spin. Olds flight had destroyed three MiG-21s without suffering a loss and at its fuel consumption limits left the area.
Ford flight, led by 8th TFW Vice Commander Colonel Daniel "Chappie" James, Jr. entered the target area at 1505, just as the MiGs began to engage, and James radioed a warning to Olds. Though he did not score a victory himself, James witnessed the victory made by his wingman, Captain Everett T. Raspberry:
"At 15:04 my flight was attacked by three MiGs, two from the ‘10 o’clock’ and one from the ´6 o’clock´. Initially I didn’t see this last one because I had been concentrating on those approaching head-on. My WSO excitedly warned me about this rapidly approaching MiG, which was within firing range of my #3 and #4. I hesitated a while before interrupting my attack against the two MiGs in front, because I had seen the ‘Olds’ flight passing below us a few seconds before. I thought that the plane seen by my WSO could be one of them. Despite that, I suddenly turned left and then right, and caught sight of the third MiG. I ordered to my numbers 3 and 4 to break right. As they did so, the MiG broke left for some mysterious reason and for a split second we were side by side. We were so close that, besides the red stars in his wings, I could clearly see the pilot’s face. I began a horizontal barrel roll to get away from him and into an attack position, once in position, I launched a Sidewinder. The missile missed because the evading MiG broke left at full throttle. But when he did it, he put himself in the line of fire of my number 2, Captain Everett T. Raspberry. I ordered him to follow the prey, because the two aircraft that I initially saw had been placed in my forward sector. I was in an advantageous position, so I fired two AIM-9s against them in a quick sequence, and I turned to place myself as wingman of my #2, Captain Raspberry. […] I kept on descending besides Captain Raspberry and I remember that I thought that he was still out of the optimal launching envelope. But he performed a barrel roll that placed him in a perfect position again and he launched an AIM-9 which hit against the tail section of the MiG-21. It was shaken violently and later fell in a slow, almost plane spin.”
James, preoccupied with two MiGs approaching Ford flight head-on, was attacked from the rear by a MiG-21. He executed a horizontal barrel roll, got behind his attacker, and fired an AIM-9 that the MiG evaded. The move to evade James put the MiG in front of Raspberry, who shot it down with a missile hit behind the cockpit. After Ford 02 scored its kill, Ford flight left the scene without loss, its success due partially to the high-speed maneuverability of the F-4 at high altitude.
Rambler flight, the third into the area, was led by Captain John B. Stone, the wing tactics officer and one of the architects of Operation Bolo. 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 second Sparrow hit one of the MiGs. Observing a third MiG behind him, he coordinated his maneuvers with his wingman and steered the MiG into the line of fire of Major Philip P. Combies (Rambler 04). He saw the battle in this way:
"We flew at 13,440 feet (4,800 meters) above sea level and our speed was 540 knots. 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 than us. Two more MiGs appeared 2 miles –about 3 km - behind. . . . When the MiGs crossed in front of Stone, he started to follow, breaking left and losing height. Due to that, the flight spread wide to the right, and I found myself higher and somewhat to the right than the others. I kept the throttle to the minimum during the first phase of the combat. So, the MiGs broke to the left, and the engagement began. I choose one of the MiGs and followed him with my radar. I don't think that we ever exceeded 4 g during the whole engagement. I decided to follow the Navy pilots' tactics - at close range foregoing the radar tracking, but looking through the reticle instead. When I realized that I was in the right position, I pushed the fire button, released it, pushed it again, and waited. I did not even see the first Sparrow. However, I followed the entire trajectory of the second one, from launch to impact. I fired the missiles at less than 2,000 yards from the MiG’s tail, height 9,800 feet (3,500 meters) and turning to the left. The second one hit the tail section of the enemy aircraft. A second later I saw a huge, orange ball of fire."
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 MiG, hit behind the tailfin, exploded in a fireball. This, the third MiG-21 downed by Rambler flight, raised the final score of the day to 7:0 in favor of the F-4s. SA-2 missile launches (five in all) began to threaten Rambler flight, which also disengaged. The entire combat lasted twelve minutes.
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 7 Mig-21 victories:
|Squadron||Call Sign||Aircraft Commander¹||Pilot¹||Missile|
|555 TFS||Olds 02||1st Lt. Ralph F. Wetterhahn||1st Lt. Jerry K. Sharp||AIM-7|
|555 TFS||Olds 04||Capt. Walter S. Radeker III||1st Lt. James E. Murray III||AIM-9|
|555 TFS||Olds 01||Col. Robin Olds||1st Lt. Charles C. Clifton||AIM-9|
|555 TFS||Ford 02||Capt. Everett T. Raspberry, Jr.||1st Lt. Robert W. Western||AIM-9|
|433 TFS||Rambler 04||Maj. Philip P. Combies||1st Lt. Lee R. Dutton||AIM-7|
|433 TFS||Rambler 01||Capt. John B. Stone||1st Lt. Clifton P. Dunnegan, Jr.||AIM-7|
|433 TFS||Rambler 02||1st Lt. Lawrence J. Glynn, Jr.||1st Lt. Lawrence E. Cary||AIM-7|
Mission impact and followup
As the F-4s landed at Ubon, their ground crews lined the taxi way. As each Phantom passed, cockpits opened, the pilots indicated with upheld fingers the numbers of kills they'd scored. Of the 16 MiG-21s known to be in the VPAF inventory, 11 to 14 had been engaged (depending on the source), with 7 destroyed and two others probably shot down (by Combies and Maj. Herman L. Knapp, Rambler 03).
The success of Operation Bolo led Seventh Air Force to plan a similar mission simulating an RF-4C photo reconnaissance mission. The immediate reaction to Bolo by the VPAF was to challenge the daily "recce" mission on the two days immediately following Bolo, in each case causing the mission to be aborted. On both January 5 and January 6, 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. On the second day, intercepted by 4 MiGs, they again surprised and shot down two during the encounter, with Crab 01 (Capt. 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.
For the North Vietnamese (and their Soviet allies who supplied the MiG-21 aircraft and helped set up the integrated air defense system), the two reverses forced them to husband their assets by grounding the MiGs for several months for retraining and devising of new tactics.
- Bolo has been detailed in most literature on modern air combat, including all of the sources noted below
- Sherwood, John Darrell (1999). “Old Lionheart”, Fast Movers: Jet Pilots and the Vietnam Experience. Free Press. ISBN 0312979622. , 73
- Sherwood, 31
- Marshall L. Michel (1997). Clashes: Air Combat Over North Vietnam 1965-1972. Naval Institute Press. ISBN 1557505853. , 63
- Sherwood, p. 33
- Lou Drendel (1984). ...And Kill MiGs. Squadron/Signal Publications. ISBN 0897470567. , 11, quoting 1LT Dunnegan
- Walter J. Boyne. Mig Sweep. Boyne's account states January 2 but is apparently a typographical error. He makes it clear in the next paragraph that the mission was delayed 24 hours to January 2.
- Drendel, 12
- Sherwood, 33
- Zampini, Diego (2003). Robin Olds Mastermind of Operation Bolo. Acepilots.com. Retrieved on 2006-12-08.
- Boyd: The Fighter Pilot who changed the Art of War, by Robert Coram, page 215
- Drendel, 17-18 and 20-21