diff --git a/config.js b/config.js
index 45e2610..9a2f0d5 100644
--- a/config.js
+++ b/config.js
@@ -174,7 +174,7 @@ window.CONFIG = {
         wStrip: 1,
         // Contrails: contrailChance of the aircraft leaves a trail once
         // above contrailStartKm, visible for contrailLifeS seconds.
-        contrailChance: 1.00,
+        contrailChance: 0.85,
         contrailStartKm: 6,
         contrailLifeS: 300,
         contrailWidthM: 620,      // full trail width