Definition
A range of values in which the upper limit is ten times the lower limit. In electronics and avionics, frequency response and instrument scales are often described per decade — for example, a filter that rolls off so many decibels per decade of frequency, or a tuning range from 100 Hz to 1,000 Hz spanning one decade.
Plain English
A span where the top number is ten times the bottom number. So 10 to 100 is one decade, 100 to 1,000 is another decade, and so on.
Context Anchor
Seen in aircraft electrical, radio, and instrument-maintenance discussions when numbers are grouped by ten-times steps.
Derivation
From the Greek 'deka,' meaning ten. In everyday English a decade usually means ten years, but in technical work it simply means a factor of ten — any tenfold step, not specifically time.
Why Pilots Care
If a manual says a value changes by a decade, it means the value changes by a factor of ten, which is much larger than a small adjustment.
Analogy
Moving from 10 to 100 is one decade, like moving one major step up on a scale where each big step multiplies by ten.
Intuition Check
Do not assume decade means ten years here. In technical aviation use, it usually means a ten-times range or a group based on ten.
Example Sentence 1
The audio filter in the intercom attenuates noise by 20 decibels per decade above the cutoff frequency.
Example Sentence 2
Records showed that certain inspections were required once each decade.