We Will Not Forget 3
These are some of my notes regarding the tragic Forrestal (CVA-59) fire 50 years ago this Saturday, on 29 July 1967.
where do i buy accutane A stray electrical charge caused the inadvertant launch of a 5-inch Zuni rocket from this Phantom II.
The seminal document is the Navy’s own Manual of the Judge Advocate General Basic Final Investigative Report Concerning the Fire on Board the USS FORRESTAL (CVA-59). This 6,000+ page report is the Navy’s official conclusion for what happened that fateful day.
The proximate cause of the fire was a briefest of brief spike in electrical energy that triggered the launching of a 5-inch FFAR (folding-fin aircraft rocket), known as a Zuni, from an F-4B Phantom II.
Anaimalai The LAU-10 pod carried four Zuni rockets, often beneath a frangible nose cone that would break apart with the launching of the first rocket.
The investigation board focused on the Zuni rocket and its LAU-10 launching pod. Those aboard that day generally agreed that the rocket started the fire, but that it was confinable, fightable, that they had a chance until that first bomb went off.
The final report found that there were shortcomings in the Zuni launching pod. Attachment cords between the pod and its TER (triple ejector rack) mounting on the aircraft called “pigtails” carried the electrical firing charge from the pilot’s finger on the button to the rocket’s igniter. Pins on the pigtail could be bent causing a short circuit.
The LAU-10 was mounted on one of three positions on the Triple Ejector Rack or TER. The TER was electrically connected to the F-4B. The pigtail (circled) electrically connected the LAU-10 and TER.
Further, there were two separate safety procedures to prevent an inadvertent firing of the Zuni. One was that the pigtails were not to be plugged in until immediately before the aircraft’s launching. With the high-tempo of flight deck operations, the delayed connection of pigtails slowed down launches such that they caused conflicts with the launching of one mission and the recovery of a previous mission.
The veterans of the experienced Pacific-based carriers passed this information to the newly arrived Forrestal squadrons. (Forrestal was the first Atlantic carrier to take up station off Yankee Station, thus it had little basis for “lessons learned” in the high tempo ops off Vietnam.) Their ship’s safety committee chose to bypass this safety procedure because there was another significant device, which was highly effective.
Four LAU-10s are mounted on this Marine Corps F-4B.
That device, essentially a safety pin, mechanically and electrically prevented a rocket’s launch. Standard procedure was for that pin to be pulled only immediately before launch.
However, in some instances, again in the interest of getting the aircraft off the deck as soon as possible, crews began pulling pins before the aircraft got to the catapult.
The Navy report determined that the rocket fired when the pilot of the F-4B carrying the Zuni switched power sources.
The Phantoms required an external power source to start their engines. Once one of the engines in the twin-engined fighter was at a certain power level after being started by a “huffer,” the pilot would switch from the external source to the internal source powered by the running engine. When the pilot switched power sources there was a brief spike of electrical energy.
Of itself, that spike would not have launched a Zuni. However, with the pigtail connected, the electricity had a route to the rocket. With the safety pin pulled, the Zuni was electrically and mechanically free to be fired.
Although the report cited the errors of safety checks on the rocket, it found no one aboard the ship directly responsible for the fire and subsequent explosions.
