The USS FORRESTAL (CVA-59) fire and munition explosions

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On 29 July 1967, only eight months after the ORISKANY fire, there was another aircraft carrier fire. This time it was on the flight deck of the USS FORRESTAL (CVA-59).

USS FORRESTAL (CVA-59) – Fire on the flight deck on 29 July 1967. USS RUPERTUS (DD-851) stands by. U.S. Navy photo.

This accident happened as planes were being readied for launch on a mission over North Vietnam. The ship was part of a task force operating in “Yankee Station” in the Gulf of Tonkin off of North Vietnam. A 5-inch Zuni rocket loaded in the pod under the wing of an F-4 aircraft was accidentally fired.

The warhead crossed the flight deck, struck an A-4 aircraft puncturing the fuel tank, and igniting a fire, Figure 8.2. Two A-4 aircrafts each loaded with two 500 pound MK-82 bombs and SHRIKE missiles, one A-4 loaded with two MK-82 and two AN117A1 750 pound bombs, and seven A-4’s each loaded with two ANM65A1 1,000 pound bombs were engulfed in the fire.

LCdr. John S. McCain III, who later became a Republican Senator from Arizona, was seated in his A-4 ready to take off on a mission over North Vietnam when the fire started. He “jumped from the cockpit of his plane, ran through a wall of flames and started helping sailors on the hangar deck who were pushing bombs and missiles over the side of the ship.”19 According to the Life Magazine article, a sailor, Chief Aviation Boatswain’s Mate Gerald Farrier, took a fire extinguisher and tried to reach a bomb that was already in the flames. It detonated right in front of him. The air blast and bomb case fragments decimated the first wave of fire fighters as they were approaching to fight the blaze.

USS FORRESTAL (CVA-59) – Fire on deck. U.S. Navy Photo.

Though serious in itself, the initial fire was not catastrophic. However, only ninety seconds after the fire started a 750-pound M 117 bomb loaded with Composition B detonated killing or seriously wounding most of the fire fighters. The detonation ruptured the flight deck spilling fuel into the hangar deck below. As the fire progressed, more detonations followed.

Major explosions continued for about five and a half minutes after the start of the fire. One 500-pound bomb, one 750-pound bomb, seven 1000-pound bombs, and several missile and rocket warheads were exposed to the heat from the fire and exploded with varying degrees of violence. It took about 10 hours to extinguish all of the fires on the ship. This disaster resulted in 134 deaths, 161 injured, 21 aircraft destroyed, and 39 aircraft damaged. Figure 8.5 is a picture showing some of the debris and the damage caused by the fire and munition explosions.

Following the accident, the ship returned to the Portsmouth Naval Shipyard (VA) where 175 feet of the flight deck as well as shops and other compartments below had to be replaced. The overhaul required to repair the structural damage to the ship cost the government over 15 million dollars.

USS FORRESTAL (CVA-59)- Hole in the deck caused by a bomb detonation. U.S. Navy photo

After this tragic incident, representatives from the Naval Ordnance Systems Command (NAVORD) and the Naval Air Systems Command (NAVAIR) were summoned to a meeting in the office of RAdm. Outlaw in the Pentagon. RAdm. Outlaw’s meeting reviewed the details of the accident and discussed what could be done to minimize damage and casualties resulting from this kind of incident. A few days after this meeting, the Navy established a panel under retired Adm. Russell to investigate the accident. The Panel recommended ways to improve fire-fighting capabilities aboard the aircraft carriers and to increase safety during carrier flight operations.

RAdm. Outlaw was interested in exploring what could be done to delay the cook off of munitions and to reduce the violence of munition explosions caused by fuel fires. “Cook-off” is the term used for the event that occurs when a device loaded with an explosive material is heated beyond a critical point and the explosive detonates or explodes violently. Except for some small-scale laboratory tests, all of the cook-off data available to us in 1967 had been obtained either from studies of projectile reactions in hot naval guns or from munitions exposed to wood fires.

USS FORRESTAL (CVA-59)- Debris and damage caused by the fire and munition explosions. U.S. Navy Photo

The Navy had no data on the time a munition could endure a fuel fire without reacting or on the violence of the explosive reaction that could be expected when it occurred.

In the following weeks, the Navy established a Flag level Fire Fighting Steering Committee. Also, NAVAIR initiated an Aircraft and Ordnance Safety Program to investigate ways to extinguish flight deck fires and methods to delay munition cook-off reactions. The findings of the Adm. Russell Panel investigation and the CV Fire Fighting Steering Committee are operational issues and are documented elsewhere. Hence, they will not be repeated here.

The NAVAIR Ordnance Safety Program20 concentrated its efforts on 1) tests to measure the cook-off time and reaction violence of air-launched weapons, 2) research programs to acquire and test insulation materials and, 3) the development of methods for applying internal and external insulation to warheads to protect the explosive from the heat. Insulation, ablative materials and intumescent paints developed by NASA for the space program and other materials available on the commercial market were evaluated.

MK-82 General Purpose (500lb) bomb with “Alligator Skin” external thermal coating applied. U.S. Navy Photo

Eventually, with the combination of internal and external insulation applied, cook off times of 5 to 10 minutes were achieved for MK-82 (500 lb) bombs. However, the improved time delay for cook-off did not diminish the violence of the explosive reactions when they occurred. Also, there were no cook-off resistant booster explosives available for use in the bomb fuzing system. The booster explosive in the fuze chain also contributed to the violence of the explosive reactions when the bombs were heated.

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19“Forrestal Disaster – Inferno at Sea”, Life Magazine, August 11, 1967.
20The NAVAIR Ordnance Safety Program became known as the NAVAIR Insensitive Munition Technology Transition Program (IMTTP) shortly after the CNO IM policy was issued. This program compliments the IMAD program in that it seeks to apply the IM technology to air-launched weapons. I leave it to those more familiar with the IMTTP to document its history.