Definition
The deliberate or unintentional transmission of radio signals on a frequency in use, with the effect of obscuring, disrupting, or preventing reception of legitimate communications or navigation signals.
Plain English
Jamming is when another signal blocks or interferes with the radio or navigation signal you are trying to use, so you can't hear or rely on it properly.
Context Anchor
Pilots may encounter this term in air traffic control reports, notices, or system discussions when communication, navigation, or radar performance is being affected.
Derivation
From the everyday sense of 'to jam' meaning to block or wedge something so it cannot move. In radio use, the 'movement' being blocked is the signal getting through to the receiver.
Why Pilots Care
Jamming can cause sudden loss of GPS or radio guidance, forcing immediate transition to backup navigation and increasing workload in instrument conditions.
Intuition Check
Jamming does not only mean a physical part is stuck. In this context, it usually means interference is disturbing an aviation signal.
Example Sentence 1
The pilot reported GPS jamming over the test range and switched to VOR navigation to continue the flight.
Example Sentence 2
ATC warned of possible jamming in the area and advised using backup instruments.