Definition
An arrangement in an electrical or electronic circuit in which components are connected end-to-end so that the same current flows through each component in turn. The output of one stage becomes the input of the next, and a break anywhere in the chain stops the entire operation.
Plain English
Things connected one after another in a single line, so the signal or current passes through each one in order. If any link in the line fails, the whole line stops working.
Context Anchor
Seen in aircraft electrical, electronic, and avionics system descriptions, especially when explaining how a unit sends information or completes checks in order.
Derivation
From the Latin 'series', meaning 'a row' or 'connected sequence.' The same root gives us 'series' in everyday English. In aviation electronics, 'serial' keeps that original sense — items lined up one after another, each depending on the one before.
Why Pilots Care
Components wired in serial share a single path, so a single failure can disable the whole circuit. Knowing whether a system is serial or parallel helps a pilot understand why one bulb, fuse, or component going bad can take down a larger function.
Analogy
Serial operation is like people boarding through one door: each person goes through in order, not side by side.
Intuition Check
Do not confuse serial with a serial number. In this term, serial means one-at-a-time in sequence, not an identifying number on a part.
Example Sentence 1
The position lights are wired in serial operation, so when one bulb burned out the whole string went dark.
Example Sentence 2
During the test, the mechanic switched the system to serial operation to check each sensor output individually.