The pilot was carrying out circuit training onto a grass landing strip within a ploughed field. Following a normal circuit and approach the aircraft wheels touched down at a point at the beginning of the grass threshold of Runway 28, struck a frozen sod probably thrown up during the ploughing, and came to a sudden stop. The undercarriage was effectively severed from the aircraft and the propellor struck the ground. There was no fire and both occupants exited the aircraft safely. The pilot’s assessment of the cause of the accident was that he was blinded by the strong low setting winter sun and in touching on struck an unseen frozen sod, with the resultant damage.