The Human Relay: Fully Energized

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rhughes
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The Human Relay: Fully Energized

  It seemed like just another routine U.S. Navy avionics-maintenance task: Aircraft 501, an EA-6B Prowler, required a new left DC hold-relay. The old one had been cannibalized from another aircraft. An AE2 and an AE3 checked out their tools and manuals, placed a MAF in work, and proceeded to the hangar to install the new relay.

They ensured power was secured and then completed the installation
in accordance with the MIM. With the hard part out of the way, it was time to ensure everything was operational. The MIM calls for an
electrical power test-set (AN/ASM-439). This, however, requires
a low-power turn, which wasn’t feasible because 501 was in the
hangar for a special inspection. Instead, the two AEs opted to
manually energize the relay and check the connections. This procedure isn’t in the manual, and therefore is not an authorized method of testing the relay. They applied ground power to the jet. Then, with meter in hand, the AE3 began reading for power at all the relay terminals. Unfortunately for him, this meant sticking his hand next to a nest of wires and terminal lugs. As he reached into the
panel to read for power, he brushed up against a live wire, which jolted him immediately with a painful shock. The two secured power quickly and went back to the shop.

He felt okay at first, but after a mere ten minutes, his arms felt numb and he developed a severe headache. He was taken to medical and given an EKG, medication, and a day of SIQ.

This incident was minor, but the consequences easily could have been far worse: he could have been knocked unconscious by the shock and thrown from the top of the aircraft. Since the incident, the AE3 has educated the squadron on electrical safety, ORM, and the importance of strict adherence to maintenance procedures. As a result of this incident, the squadron implemented an additional control, wearing insulated gloves, when working around power.

 

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