time. Nor—necessarily—that the end of the winning streak, when it comes, will be as tragic as impacting against a concrete surface at 175 or so mph. But then again . . .
Let's look at some of the near misses. One crew member got his foot run over by the aircraft loading trailer. But he was wearing safety shoes, as he was supposed to. Once a lifting cable failed and a missile was dropped about six inches during an offload operation. Nothing happened: no explosions, no mangled human extremities; because explosive items like squibs and initiators are shipped separately, and because the hands and feet of loading personnel were clear of the danger area. Once a failed pin in the aircraft hoist gear sent a missile and trailer rumbling down the loading ramp at a clip which might have compared favorably with airborne cruise speed to anyone in the way. But nobody, luckily, was in the way. Everyone had been paying attention to the 2 dash 2's oft-repeated warning (repeated an even dozen times, to be exact): "Keep personnel away from down-ramp end of trailer as it is being pulled up (or rolled down) loading ramp."
Still, if you took a dim and rigorous view of these three incidents, you would conclude that personnel were only practicing about half the safety they should have been. Otherwise, we wouldn't be using the words "near miss." Good safety practices, we know, are redundant. Just as there are two or three different ways to trigger an ejection seat, so there are extra, redundant, "insurance" features associated with airlifting the IM-99A. For example: at the crucial moment when the trailer is stopped on the ramp while cargo is being shifted inside the plane, four conditions would have to exist before anyone could be hurt by a runaway missile and trailer:
- (1) A hasty and incomplete preliminary inspection of loading gear: trailer, cable, snatch blocks, Pullift hoists, etc.;
- (2) Disregard of the warning in the 2 dash 2 about staying clear of the downramp end of the trailer;
- (3) Failure to attach the safety restraint chains which are normally hooked between the loading trailer and the body of the C-124; and
- (4) Failure to set the trailer hand brake. Each procedure serves to back up the others. Two are physical restraints; two depend on the human element. All are essential for 100 per cent safety.
So much for near misses where "insurance" paid off. There have also been cases where survival was strictly a matter of luck. The incident that comes most readily to mind happened a short while ago, during a two-missile offloading. Normal sequence is to move the port missile all the way aft in the C-124, load the starboard missile on the offloading trailer, and steer missile and trailer on down the ramp. The manual says: "Station one man at hydraulic hand pump and gage position at right rear of trailer and one at hand brake and directional valve position at left rear of trailer. Station others as needed to observe and direct trailer loading." "Rear of trailer" in these instructions means forward in the plane; or the end closest to the ramp. On this particular operation, however, it seems there was also a man—call him Smith—on the front end of the trailer (aft in the C-124), riding on the chassis to control a parking brake. As the outgoing missile passed by the elevator stub of the other missile, Smith got wedged in between. Fortunately, another crewman, stationed near the back end of the trailer, had both Smith and the anchor vehicle operator in his line of vision. He saw what was happening and signalled the wrecker operator to stop towing. Smith was extricated from a squeeze which could have been fatal. To quote from a subsequent field report: "At this point the crewman is on the trailer controlling the emergency (parking) brake. His back is extremely close (brushes) the elevator stub of the other missile . . . Should anything happen at this instant, the crewman's life would be in danger."
Boeing engineers tackled the problem raised in this field report, and came up with the following recommendations:
- (a) Steer the trailer with the steering selector which is closest to the front of the C-124, 'til Smith's station is clear of that elevator stub.
- (b) The only break to be used during loading is the hand brake. The parking brake—required by MIL-M-8090—is only to keep the empty trailer from breaking loose, and should not be used when the missile is aboard. A lot of force has to be put on this brake to hold an empty trailer on a 17 degree incline, so it would be virtually useless as a physical restraint on missile and trailer.
- (c) Finally, to quote again: "There is no T. O. requirement for a man to ride the trailer. A man riding the trailer during operation is subject to any accident that might happen to the trailer."
Before we criticize Smith too severely, however, we should note that his purpose in riding the trailer was apparently to add still another item of safety insurance to the four mentioned previously. So that the intention, at least, was good.
Technical Manual T. O. 21-IM99A-2-2 is the bible for Bomarc airlift loading procedures. Updated every three months, these 2 dash 2 instructions are the end product of dozens of on-the-spot observations at both on and offloadings, conferences with handling equipment design engineers, and coordination with Safety Engineering. The latter group utilizes extensive test facilities and works along with other groups, like Reliability and Human Factors engineering, to solve safety problems which have already arisen and to find out how future ones can be prevented. Often, solutions to local, in-house contractor problems can be applied to similar conditions in the field.
For at least two men, however, safety is consider-
when you're moving a missile to its new home. It's a job requiring detailed
safety on all sides. Togetherness, then, is the word.
| DECEMBER 1960 |
| 7 |
