[scottyboy75]

Could be from not smoothly lowering the collective during the landing. If you come in hot and leave the collective up you will slide forever. This is bad because it raises the potential for dynamic rollover. Or if they are practicing running takeoff it could be longer. The skids stay in contact with the ground until you reach ETL then you can get off the ground. This might be the reason for the longer slide marks. Other than cosmetic is it really damaging the asphalt?
Shane