That means the DA was better than the standard air, you had mine shaft air when your engine was run , so it took power away, most time it is the other way
It was a decent day outside - temp was low to mid 60s, bright and sunny with no real humidity, maybe 15%. Looking at weather data from that day I believe the barometer was 30.3-30.4? Here on Long Island, we are basically at sea level.
Wish I would have asked what the specific weather inputs were, would have been helpful to know and it didn't occur to me to ask the operator. Next time.