Military Aviation

Loose deuce Vs fluid four: during the Vietnam War the fighting tactics used by US Naval Aviators were better than those of the USAF pilots – here’s why

The loose deuce formation, which presented a variation of the famous ‘Thatch Weave’ developed during World War 2, was vastly different to the rigid ‘fluid four’ formation flown by USAF pilots.

During the Vietnam War, US Navy F-4 Phantom II fighters used a two-aeroplane basic fighting unit known as a section and employed an air-to-air formation known as ‘loose deuce’, which placed two aircraft flying abeam of each other with a separation distance of about one mile. From this position both crews could cover the other’s rear quarter, or ‘six o’clock’, and provide mutual support.

As explained by Brad Elward & Peter e Davies in the book US Navy F-4 Phantom II MiG Killers 1965-70, the principal of loose deuce called for one aircraft (the ‘engaged’ fighter) to attack while the wingman (called the ‘free’ fighter) would manoeuvre with the engaged fighter, but far enough back to keep an eye out for other bandits or threats in the area. As the engaged fighter drove the bandit into a predictable flight pattern, the free fighter would call the shot.

This formation also gave Navy crews greater flexibility, as either aircraft could assume the engaged or free role. Moreover, both aeroplanes could operate at full power without fear of colliding with the other.

U.S. Navy F-4Bs

Loose deuce represented a departure from the standard intercept formation that saw the two Phantom IIs fly a radar trail formation, separated by approximately three miles. The lead aircraft, known as the ‘eyeball’, would essentially serve as the spotter, calling the contact to the trailing Phantom II, which would then take a shot with a Sparrow. This separation preserved the requisite minimum distances needed for a successful AIM-7 launch, but proved unworkable in a close-in dogfight scenario within the Sparrow’s parameters.

At the heart of the loose deuce formation was the ability to provide mutual support, both offensively and defensively. Mutual support, from a tactical perspective, is obtained when each aircraft can readily clear his counterpart’s rear-aspect of aerial threats. And, while the military lead of the section never changes (usually the senior aviator), the tactical lead is held by the aircraft with the best tactical position to see, evaluate and direct the flight.

The man with the initial contact (radar or visual) has the lead (be he the wingman or RIO), and calls a ‘turn’ on UHF, followed by a description of the bogie position and composition. In any event, the tactical lead must maintain sight of his wingman.

The loose deuce formation, which presented a variation of the famous ‘Thatch Weave’ developed during World War 2, was vastly different from the rigid ‘fluid four’ formation flown by USAF pilots. Fluid four was based on a four-aircraft flight split into two elements of two aeroplanes. In a dogfight, the two element leads, numbers 1 and 3, would engage the bandit in a similar fashion to the loose deuce, with the exception being that the two wingmen, numbers 2 and 4, served solely to protect their element leaders, numbers 1 and 3.


The wingmen flew as a ‘welded wing’ or ‘fighting wing’, staying within 1500 to 2000 ft behind their leader, and offset about 45 degrees. This formation worked fine when the aeroplanes were slower and propeller-driven, as in World War 2, but it was unworkable with the fast-moving jets of the 1960s. Welded wing pilots found they were so intent on staying in formation, and keeping from hitting their element leader, that they simply did not have an opportunity to look for the bandits in the area.

Fluid four flights also suffered from a ‘single shooter’ policy that meant that only the flight leader could take a shot — the remaining fighters were along to protect the leader as he went after the MiGs. Naturally, this policy drastically reduced the offensive capabilities of the formation since only one of the four aeroplanes could shoot.

Capt Jim Ruliffson, a former F-4 pilot and commanding officer of Topgun, remembers one situation where a USAF flight lead had expended all his missiles in pursuit of a MiG. When one of his wingmen called out that he had the MiG in his sights, and asked for permission to fire, the flight leader denied his request and ordered the flight to return to base!

US Navy F-4 Phantom II MiG Killers 1965-70 is published by Osprey Publishing and is available to order here.

Photo credit: U.S. Navy and U.S. Air Force

This print is available in multiple sizes from – CLICK HERE TO GET YOURS. F-4J Phantom II VF-96 Fighting Falcons, NG100 / 155800 / 1972 – “Showtime 100”
Dario Leone

Dario Leone is an aviation, defense and military writer. He is the Founder and Editor of “The Aviation Geek Club” one of the world’s most read military aviation blogs. His writing has appeared in The National Interest and other news media. He has reported from Europe and flown Super Puma and Cougar helicopters with the Swiss Air Force.

Recent Posts

The K-19, the first Soviet nuclear-powered strategic missile submarine that experienced a reactor failure on the first missile-firing voyage

The K-19 Project 658 (NATO reporting name Hotel I-class) K-19, the first Soviet nuclear-powered strategic… Read More

11 hours ago

USAF F-16 Pilot explains why a Viper is more comfortable than a commercial airplane for long-haul flights

Fighter pilots Utilizing extraordinary skill and precision, fighter pilots push their aircraft’s limits with complete… Read More

12 hours ago

US Navy EA-18G Growler pilot explains why pulling 9Gs feels like an elephant is standing on your chest (and it very quickly begins damaging your body)

G-LOC G-induced Loss Of Consciousness (abbreviated as G-LOC) is a term generally used in aerospace physiology to… Read More

1 day ago

US Navy F-4 RIO recalls when his Phantom II was mistakenly shot down by a US Navy F-4 (flown by a USAF exchange pilot)

The F-4 Phantom II In response to Navy requirements for a high-altitude interceptor to defend… Read More

1 day ago

US Navy A-7 pilot recalls taking his Corsair II as high as possible during Post Maintenance Check Flights

The Corsair II The A-7 Corsair II was initially developed in response to a 1963… Read More

2 days ago

USAF F-16 pilot tells why the F-15E Strike Eagle can’t hold a candle to an F-22 Raptor in an up close and personal engagement

F-15E Vs F-22 Developed to meet the US Air Force (USAF) requirement for air-to-ground missions, the… Read More

2 days ago