Arrival in Gulf of Tonkin Forrestal departed its home port in
Norfolk, Virginia in early June 1967. After it completed required inspections for the upcoming West Pacific cruise, it sailed to Brazil for a show of force. It then traveled east around the
Horn of Africa and visited
Naval Air Station Cubi Point in the Philippine Islands before sailing to
Yankee Station in the Gulf of Tonkin on 25 July. After arrival at Yankee Station, aircraft from
Attack Carrier Air Wing 17 flew approximately 150 missions against targets in
North Vietnam over four days.
Vietnam bombing campaign drops a load of
Mark 83 bombs in 1970; the relentless bombing campaign had led to the Navy's stocks of Mark 83 bombs dwindling, and had forced on them the use of World War II surplus ordnance, often in poor condition, to maintain the punishing mission rate. The ongoing naval bombing campaign during 1967 originating at Yankee Station represented by far the most intense and sustained air attack operation in the
U.S. Navy's history. The demand for
general-purpose bombs (i.e., "iron bombs") greatly exceeded production. The inventory of bombs dwindled throughout 1966 and became critically low by 1967. A
carrier-launched A-4 Skyhawk, the Navy's standard light attack /
ground attack aircraft, could carry either a single bomb, or two 1,000 lb bombs. The latter gave it the ability to strike two separate hardened targets in a single
sortie, which was more effective in most circumstances. The
U.S. Air Force's primary ground attack aircraft in Vietnam was the much heavier, land-based,
F-105 Thunderchief. It could simultaneously carry two
M118 bombs and four
M117 bombs. The Air Force had a large supply of these bombs, and did not rely as heavily on the limited supply of 1,000 lb bombs as did the Navy.
Issues with Zuni rockets In addition to bombs, the ground attack aircraft carried unguided
Mk-32 "Zuni" rockets. These rockets were in wide use although they had a reputation for electrical difficulties and accidental firing. It was common for aircraft to launch with six or more rocket packs, each containing four rockets. However, these tests were conducted using the new Mark 83 1,000 lb bombs, which featured relatively stable
Composition H6 explosive and thicker, heat-resistant cases, compared to their predecessors. Because it is
relatively insensitive to heat, shock and electricity, Composition H6 is still used as of in many types of naval ordnance. It is also designed to
deflagrate instead of
detonate when it reaches its ignition point in a fire, either melting the case and producing no explosion at all, or, at most, a subsonic
low order detonation at a fraction of its normal power. eventually being improperly stored in open-air
Quonset huts at a disused
ammunition dump on the periphery of Subic Bay Naval Base. Unlike the thick-cased Mark 83 bombs filled with Composition H6, the AN-M65A1 bombs were thin-skinned and filled with
Composition B, an older explosive with greater
sensitivity to heat and shock. Composition B also had the dangerous tendency to become more sensitive if it was old or improperly stored.
Forrestals ordnance handlers had never even seen an AN-M65A1 before, and to their shock, the bombs delivered from
Diamond Head were in terrible condition; coated with "decades of accumulated rust and grime" and still in their original packing crates (now moldy and rotten); some were stamped with production dates as early as 1953. Most dangerous of all, several bombs were seen to be leaking liquid
paraffin phlegmatizing agent from their seams, an unmistakable sign that the bomb's explosive filler had degenerated with excessive age, and exposure to heat and moisture. the concern felt by
Forrestals ordnance handlers was striking, with many afraid to even handle the bombs; one officer wondered out loud if they would survive the shock of a
catapult-assisted launch without spontaneously detonating, and others suggested they immediately jettison them. In one concession to the demands of the ordnance handlers, Beling agreed to store all 16 bombs alone on deck in the "bomb farm" area between the starboard rail and the carrier's island until they were loaded for the next day's missions. Standard procedure was to store them in the ship's magazine with the rest of the air wing's ordnance; had they been stored as standard, an accidental detonation could easily have destroyed the ship. ==Fire and explosions==