SAFETY
in December. He says it would be diffi cult to summarize in a short article the changes that were incorporated after three years of intense study and debate, but he notes the standard is now “a how-to manual instead of a thou-must-do regulation.” Two key changes came out of
this revision. One, machines should be designed better for lockout and manufacturers should supply guidance on how to lockout and do alternative procedures. The second change focuses on how to properly document alternative procedures when a worker cannot lockout because power is necessary to do the task. A more detailed explanation of the new standard can be found in Grover’s article on the topic, found at https://ohsonline. com/Articles/2017/03/01/Z244. aspx?Page=1.
LOCKOUT IN AVIATION LOTO is essentially a safety procedure that ensures dangerous machines are properly shut off and unable to be started up again until the completion of maintenance or servicing work. The procedure requires that hazardous energy sources be “isolated and rendered inoperative” before work begins on the equipment in question. A worker locks the isolated power sources and puts a tag on the lock identifying himself as the person who placed the lock on it. Only the worker in question has the key for the lock, meaning that only he or she can restart the machine. This prevents the accidental startup of machinery while it is in a hazardous state. The practice sounds simple enough, but gets a little more complicated in aviation. Grover explains, “Aircraft can
be very challenging to lockout, for one unique reason, that a lot of machinery does not have —
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redundancy and backup systems that support everything they are going to be working on. Whether it’s the fl aps on the wing, the pumps to the fuel tank or the communication systems, there are multiple feeds to power each device they are isolating.” He continues, “You not only
have to lockout the main feed that’s powering the section of the aircraft you are working on, you have to know where the backups will come from and isolate those as well.” Grover gives an example of what might happen if this is not done. Let’s say a mechanic wants to work within the wing on a section of the mechanical fl ap-positioning equipment. If he locks out the main power source, then crawls in there to perform work, the computer may sense a power failure to the fl ap- positioning system and reactivate the motors and drivers that make the fl ap articulate. The fl ap can then retract even though the mechanic thought he was protected by his primary lockout.”
LOCKOUT-TAGOUT STEPS Grover lists seven main steps to fully protect workers during lockout/ tagout. 1) Prepare for shutdown. Before the authorized employee shuts off the machine, he or she must know the type and magnitude of the energy and its hazards. And, the employee also must know how to control the energy by reviewing the machine-specifi c procedure then assembling necessary safety equipment.
Grover states, “They need
to recognize when they are in a situation where lockout is going to be necessary. If they are taking off protective guards or covers that keep them away from moving parts, that is a sign that lockout should be in place. Also, if there is a protective system that
may sense they are in there or opening a door, they also must do lockout before that safety device is bypassed.”
2) Notifi cation. Before lockout devices can be applied, either the employer or the authorized employee must notify the aff ected employees of the work to be done.
3) Shutdown. The machine or equipment must be turned off following orderly, established procedures. Shutting down the machine must not create any increased hazards from equipment stoppage.
4) Isolate equipment. The authorized employee who is performing the serving or maintenance work is to isolate the machine or equipment from its energy sources. The energy-isolating devices (disconnect switches, circuit breakers, valves, etc.) must be physically located and operated by the authorized employee.
“They need to understand the machinery they are locking out. In the case of an aircraft, they are going to need to know what redundancies are in place, and lock out each every one of them,” Grover says. “It’s important that they work from lockout procedures that have been developed for the equipment, so that each person who works on that equipment follows the same procedures and gets the same results. Every stored energy source must be understood, and the directions to properly isolate them should be consistently followed.”
5) Apply lockout devices and safety padlocks. The authorized employee is to apply lockout devices and personal safety padlocks bearing the identity of the worker to each energy- isolating device. Lockout devices
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