Is the F-16's cockpit pressurized? If so, why does the pilot receive oxygen from the mask (please state the correct terminology for this)? Is it due to redundancy in case cabin pressurization fails?
Yes, the cockpit of the F-16 is pressurized. However, there are two types of cabin pressurization:
Isobaric Pressurisation: The system maintains a constant cabin pressure (usually between 2000 and 8000 ft) as the atmospheric pressure decreases. This is used in commercial aircraft.
Hypobaric Pressurisation: In such a system the pressurisation commences at a given altitude and cabin altitude is maintained at this value until a preset pressure differential is reached. With continued ascent the pressure differential is maintained. This is used in military aircraft including the F-16, as the weight penalty of the Isobaric system would seriously affect the range.
Provision of supplemental oxygen in the aircraft ensures that the occupant receives increasing quantity of oxygen in the inspired air. The aircraft oxygen system (regulator assembly) ensures that the correct percentage of oxygen is added from the on-board Oxygen reserve to the inspired air in order to maintain lung pO₂ at 103 mm Hg.
It is pressurized yes. Above you can see the schedule. Note that at high altitudes the cockpit altitude would be considered high (low pressure) and insufficient to avoid hypoxia.
If the oxygen system (OBOGS) fails, the procedure is to "Descend to cockpit altitude below 10,000 feet", which is about 24,000–26,000 feet based on the pressurization schedule.
Yes. Like most fighters the cockpit of an F-16 is pressurized, primarily for pilot comfort. Use of an oxygen mask is required equipment for high altitude operations and for emergency situations. The pilot has a pressure breathing on demand oxygen mask, which is required equipment for high-altitude operations.