I have just started doing my first loops and rolls, have done about 5 loops now but on my last attempt i tried to hold it inverted for a few seconds at the top of the loop. I soon lost it in the bright sun light (my excuse) and ditched it hard, i was amazed at the minimal damage, bent main shaft, bent spindle, bent flybar, stripped main gear and a set of servo gears! I think its important to crash now and then to find your limits. For me the ground is the limit!!!!!