| According to the certification standard, the defog fan circuit is essential for flight but the cabin fan circuit is not essential. |
| He also mentioned that it was raining hard and, without air-conditioning, he had the heat on full blast to defog his windows. |
| To counter this problem, a defog vent blower fan is installed in the cockpit and, coupled with the aircraft heater, provides a recirculating airflow to reduce the fogging of the windshield and side windows. |
| The defog fan is used to increase airflow via the foot outlet, windshield outlets and side window outlets in the cockpit. |
| Well, have you ever wished that there was a way to defog the windows in your car without waiting for that heater? |
| Installation of the defog fan is a certification requirement for this aircraft and, accordingly, it is an essential load. |
