Definition
The practice of recording selected engine operating parameters at regular intervals over time and analyzing the resulting data to detect gradual changes that indicate developing problems before they become failures.
Plain English
Tracking how an engine's performance numbers change over time so you can spot trouble early, while it is still small.
Context Anchor
Seen in engine maintenance records, engine health programs, and powerplant inspections where repeated readings are compared over time.
Derivation
From 'trend' (a general direction in which something is moving) and 'monitor' (to watch and check over a period). Together: watching the direction the numbers are heading.
Why Pilots Care
Enables early detection of engine issues so maintenance can be planned ahead of time, avoiding in-flight failures and extending component life.
Grounding Statement
One engine reading may look acceptable by itself, but several readings over time can show that the engine is steadily changing.
Intuition Check
Trend monitoring is not just checking whether one reading is within limits today. It is watching the direction of repeated readings over time.
Example Sentence 1
The maintenance team uses trend monitoring to compare each flight's exhaust gas temperature against the engine's baseline.
Example Sentence 2
Operators use trend monitoring to schedule compressor washes before performance loss becomes noticeable in flight.