Titan II Accident 374-7 Damascus AR, October 8th 1976
There was no such thing as routine maintenance in the Titan II program. Routine tasks had to be thought out to ensure that the complexity of the launch facility did not hinder the maintenance operation at hand.
On October 8th, 1976, a four man maintenance team was sent to Launch Complex 374-7 to clean up hydraulic fluid that had sprayed onto the missile the day before from a ruptured work platform hydraulic hose. This work involved wiping down the missile with rags soaked in Freon 113. As the rags were used up, they were dropped down into the flame deflector for collection when the task was complete.
When they finished wiping down the missile, several team members descended into the flame detector from Level 8 to clean the puddled hydraulic fluid. They were ordered out of the area by the missile combat crew commander when several of the team members became dizzy. They had left the Freon soaked rags on the floor of the flame deflector, and the decision was made to go back and retrieve them. Sgt Mark Davis was the first to go back down to retrieve the rags. He held his breath as he bent over to pick up the rags because the odor of Freon was quite strong. He became ill and returned to Level 8. Sgt Larry South then descended into the "W" and resumed retrieving the rags. A1C Larry Woods noticed South was having difficulty as he bent over to pick up the rags and relayed this information to the missile combat crew commander in the launch control center. The commander ordered everyone out of the launch duct. South was able to climb the ladder to the Level 8 launch duct access door but collapsed in the silo equipment area at approximately 1500. South was declared dead on arrival at the base hospital.
The highly volatile Freon 113 was heavier than air. The residue left on the rags, as well as all the fumes generated in wiping down the missile, had accumulated in the lowest area of the launch duct, the bottom of the "W". As more rags were dropped, the layer of displaced air became thick enough so that when South began to collect the rags, he was breathing an anoxic (minimal oxygen) atmosphere. There was meager air circulation in the area of the flame deflector, only 60 cubic feet per minute were removed from the area by Exhaust Fan 104, and the duct was 8 feet above the floor. South had entered an area that was most likely blanketed with perhaps an 8 foot thick layer of predominately Freon 113 fumes and, by bending over to pick up the rags, had repeatedly inhaled the concentrated fumes.
Capt Bill Howard, the Technical Engineering Division engineer assigned by the Missile Potential Hazard Team to investigate the cause of the fatality, arrived at the launch complex only to find that the missile combat crew had been ordered to purge the launch duct. Howard donned his CHEMOX unit anyway, as ordered, and descended into the "W" carrying an oxygen meter and portable vapor detector (PVD) unit to check for propellant fumes. With the launch duct exhaust system running, he was fairly sure that no residual gases would remain, but he still had to run the check. As he suspected, oxygen levels were back to normal, and the portable vapor detector had given no propellant fume indication. Now the supposition had to begin.
Chief missile facilities engineer Jimmy McFadden disputed the belief of the 308th wing commander that stated that the flame deflector was inadequately designed to sustain life, causing the loss of one life and nearly two. McFadden explained that it was not a design flaw; there had never been a design requirement for any greater air turnover in the bottom on the flame deflector. There was, in fact, more than sufficient air, even though stationary, to support occupation for a reasonable amount of time.
Needless to say, this was a case of small oversights compiling into a fatal accident. Both Howard and McFadden had not known of the habit of dropping the rags to the bottom of the silo for later retrieval or of the amount of Freon 113, nearly 2.5 gallons, that was routinely used. If they had, they would have required entry onto the floor of the flame deflector to be considered only after the area had been purged for several minutes. After the accident that maintenance protocols for use of Freon 113 were modified to include a log of the amount in use, kept by the missile crew commander, and the declaration of off-limit areas until air quality was checked.
This accident was to be over shadowed by the accident that took place at this same complex on September 18th 1980.
Links to other Titan II accidents can be found on the Titan II home page here.