Definition
In a Full Authority Digital Engine Control (FADEC) system, digital channels are the independent electronic computer pathways within the engine control unit that receive sensor data, process it, and send commands to the engine. FADEC systems typically use two redundant channels so that if one fails, the other takes over engine control without interruption.
Plain English
Separate computer circuits inside the engine's electronic control box. Each one can run the engine on its own, and there are usually two so that if one breaks, the other keeps the engine running normally.
Context Anchor
Seen in discussions of FADEC-equipped engines, especially when explaining how the engine control system monitors itself and keeps working after certain faults.
Derivation
Digital' comes from Latin digitus (finger), later used for counting and then for systems that handle information as discrete numbers (1s and 0s) rather than continuous signals. 'Channel' comes from Latin canalis (pipe, groove), meaning a dedicated path along which something flows -- here, electronic signals and commands.
Why Pilots Care
Redundant digital channels ensure that a single failure in the control system does not result in loss of engine control, directly supporting flight safety and reliability.
Intuition Check
Do not read 'channels' here as radio channels. In this context, digital channels are separate computer control paths inside the engine control system.
Example Sentence 1
The FADEC's two digital channels operate independently, so a fault in one does not affect engine operation.
Example Sentence 2
When one digital channel reports a fault, the system automatically transfers control authority to the remaining channel.