In order to maintain authenticity the biplane show at Rhinebeck used a grass field. It was sort of flat. At one end there was a nasty dip. And there was an uphill. From the other perspective it was a downhill made to help you gain takeoff speed. All in all it was not so even and a challenge to takeoff and land. I am told there have been accidents. But in all my visits there were only a few close calls.