Performed prepaid maintenance on a 2011 trane heat pump split system. During inspection found all motors operating normally and the refrigerant pressures reading good. The condition of the air handler in the attic is OK considering the age. The outdoor unit is starting to suffer from heavy corrosion on the compressor and the filter dryer as well as the copper running through the outdoor unit which is scaling. I recommend replacing the system before it dies due to these corrosion issues. Spoke with customer about these issues, she is going to let the system run hoping for it to make it to spring when she will then replace it. No further action is needed. Pictures are enclosed of the two travel areas