To initiate a low Urdal make sure not to have too much altitude. Make a plain and simple loop. Coming out of the first loop just continue looping a second time. Make sure to keep the aeroplane close to ground for the final touch. Coming out of the second loop there is not enough altitude to avoid impact, thats normal, just let the wheels do their thing and bounce the plane back into the air. Voila - a Low Urdal.