A uk Rape crop would have been planted last autumn and overwintered as small plants and only now just now getting going, at this point it is still fleshy stemmed but as the summer progresses it does toughens up and become almost impossible to walk through. Obviously a nosewheel aircraft rolling into it even this early in the growing season would be retarded quickly and likely flip on to its back if going fast enough. Cereal crops at this time of year are not much more than longish grass.