There were two safeguards designed to prevent accidental missile firings: a pin, which, when inserted, physically broke the firing circuit, and there was the pigtail, which connected the firing circuit to the missile pod. Until the plane was on the catapult ready to take off, the pin was supposed to be inserted, and the pigtail left disconnected. Once the plane was on the catapult, an accidentally launched missile would have zoomed down the deck and crashed into the sea harmlessly. This is correct, other than I find the wind pulling the pin out hard to believe. You had to depress a plunger to pull the pin.
On land this is how we armed rocket pods. Sat at the end of the runway more than a few times plugging in connectors and pulling pins. The drill was to exit under the plane and show the pilot a handful of pins. Same pin pulling for bomb racks.
I find the wind pulling the pin out hard to believe. You had to depress a plunger to pull the pin. According to part 2 of the investigation report:
- Some pins were found adrift on the flight deck after launches (finding #259).
- Some F-4's arrived at the catapult missing pins (#260).
- Pins occasionally failed mechanically and were pulled out by wind or jet blast acting on the attached red warning flags (#261).
Also worthy of note: the wind was 32 knots, or 37 mph, a stiff breeze (part 1, finding #63).
There were at least three opportunities to have prevented the disaster, all of which failed:
- If they had not changed the procedure to require removing the pigtails prior to reaching the catapult (finding #230), it would not have happened.
- If the safety pin had been properly designed, it would have stayed in place, and the disaster would not have happened.
- If the F-4's electrical system had not been flawed, switching to internal power would not have caused a surge (see #123), and the Zuni would not have launched.