01 / ENGINE HISTORYReview
A persistent change at idle
Cylinders 1 and 3 became cooler at low power in March 2026. Their temperatures catch up when power is applied.
Read the idle findingsThe N6206 engine archiveCessna T206H · Lycoming TIO-540-AJ1A
Every flight leaves
a story in the data.
Two and a half years of flying, from the Colorado mountains to the Pacific Northwest. A closer look at what changed, what stayed consistent, and what deserves attention.
The idle change, in one view.
CURRENT REVIEWTwo cylinders began running cooler at idle in March 2026.
Head temperature relative to the other cylinders, °F.
C1 · Cylinder 1C3 · Cylinder 3
11-recording rolling mediansUnderstand this change ↗
541
Flight-bearing logs
419.6 h
Recorded engine running
1.57 million
Timestamped samples
2024 — 2026
Data through October 11
A lifetime in perspective
The findings that matter.
Plain-English explanations first. The measurements and their limitations are always close behind.
02 / ENGINE HISTORYReview
Boost and cool oil
The higher manifold-pressure episodes cluster around takeoffs with cooler oil. Warm settings show a smaller shift too.
See the relationship03 / ENGINE HISTORYHistorical
Less fuel. Hotter exhaust.
For a period in early 2025, comparable departures used substantially less fuel while exhaust temperature rose.
Investigate the period04 / ENGINE HISTORYImproved
Better injector balance
The October lean tests brought the cylinders closer together. The measured spread is roughly half July’s.
Compare the lean testsNew · February–March 2025 route study
Put the fuel-flow
change on the map.
Follow the actual GPS tracks. See the airports, select a journey, and move along its route with the recorded engine readings.
16journeys4airports14.8 hairborne
Explore the route studyACTUAL RECORDED GPS TRACKS
Built to be examined
Follow a finding back to the evidence.
Read the full 17-section report, explore the flight measurements, or download the original logs for your own analysis.
Open the data library