What happened
On March 8, 1982, a Boeing 707-131 owned and operated by Trans World Airlines (TWA) was undergoing routine maintenance at an airport in Las Vegas, Nevada. The incident occurred during ground operations with no intent to fly. Maintenance personnel were addressing a malfunctioning servicing valve on the forward water tank.
To diagnose the issue, a TWA mechanic entered the forward electronics bay to inspect the valve control mechanism. Simultaneously, the lead mechanic remained outside the compartment and operated the valve controls. The valve functioned normally, prompting the lead mechanic to announce that the repair was successful. Shortly after this confirmation, another mechanic looked into the compartment but observed no one inside before securing the hatch.
The absence of the mechanic inside the bay went unnoticed until the following day. On March 9, 1982, the aircraft departed Las Vegas for St. Louis, Missouri. Upon arrival, a search was initiated by the Las Vegas station manager, which led to the discovery of the mechanic's body within the electronics compartment.
The investigation
An autopsy determined that the cause of death was electrocution. The mechanic had come into contact with several 115-volt relays located in the electronics compartment. Evidence from the autopsy indicated that the individual had slipped, striking his head before falling onto the energized relays.
Findings
The primary causal factor was electrocution resulting from contact with live electrical components. The incident highlights critical safety failures regarding lockout/tagout procedures and communication protocols during maintenance on aircraft like N750TW (implied context of TWA fleet, but strictly adhering to source: the aircraft involved). The failure to verify the presence of personnel before securing the hatch allowed the individual to remain trapped in a hazardous environment.
Safety message
This incident underscores the necessity of strict verification procedures when working in confined spaces with electrical hazards. Maintenance teams must ensure that all personnel are accounted for and that power sources are properly isolated before sealing compartments.