Use during Vietnam War
By May 1967, Navy pilots had dropped several bombs in Vietnam with great success. On 19 May 1967, Ho Chi Minh’s 77th birthday, a Navy aircraft from the USS Bon Homme Richard scored a direct hit against the Hanoi power plant with a Walleye. The Navy hit the plant again with the bomb two days later, knocking out Hanoi’s major source of power.
While softer targets such as power plants proved quite vulnerable to the Walleye, sturdier ones such as North Vietnam’s well-constructed railroad bridges could not be downed even with a 1,100-pound weapon. Direct hits by the Walleye against the Thanh Hoa Bridge south of Hanoi in 1967 failed to take down even a single span of this notoriously strong structure.
Walleye II, "Fat Albert"
To correct this major deficiency, China Lake developed a 2,000-pound version of the bomb, and deployed it to Vietnam in time for President Richard Nixon's Linebacker raids against Hanoi and Haiphong. The new Walleye II, or “Fat Albert” as it was nicknamed after the cartoon character, officially designated Guided Weapon Mk 5, had an extended range data link and could hit targets up to 45 nautical miles (83 km) from its launch point. On 27 April 1972, a flight of eight Air Force fighters, two carrying 2000-pound laser-guided bombs and two carrying Walleye IIs, attacked the Thanh Hoa Bridge. Cloud cover prevented the LGBs from being used, but five of the Walleyes locked on, causing heavy damage to the bridge, even though failing to bring down a span. On 13 May, the Air Force finally brought down the bridge with 3,000 and 2,000-pound LGBs. The Vietnamese, however, soon repaired the bridge, compelling the Navy and Air Force to fly 13 more missions against the target. On one such mission on 23 October, four A-7 Corsair pilots from the carrier USS America took down the bridge with a combination of Walleye IIs and conventional 2000-pound bombs.
Guided Weapon Mk 6 was a nuclear version of the Walleye II, using a W72 warhead of 625 tonnes (615 long tons; 689 short tons) yield; no nuclear Walleye IIs are known to have been actually completed. Versions with an extended-range data link were designated in the Mk 20 series.