diff --git a/src/aircraft.h b/src/aircraft.h
--- a/src/aircraft.h
+++ b/src/aircraft.h
@@ -90,8 +90,8 @@ struct Aircraft : public SpecializedVehi
 	bool IsPrimaryVehicle() const                  { return this->IsNormalAircraft(); }
 	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const    { return this->cur_speed; }
-	int GetDisplayMaxSpeed() const { return this->max_speed; }
-	int GetSpeedOldUnits() const   { return this->max_speed * 10 / 128; }
+	int GetDisplayMaxSpeed() const { return this->acache.cached_max_speed; }
+	int GetSpeedOldUnits() const   { return this->acache.cached_max_speed * 10 / 128; }
 	Money GetRunningCost() const;
 	bool IsInDepot() const { return (this->vehstatus & VS_HIDDEN) != 0 && IsHangarTile(this->tile); }
 	bool Tick();