WORKED DENSITY ALTITUDE CALCULATION: An airfield has a Pressure Altitude of 4,000 ft. The Outside Air Temperature (OAT) is +27°C. Standard ISA temperature at 4,000 ft is +7°C. Using the standard approximation formula DA = PA + 120 × (OAT - ISA_temp), what is the Density Altitude?

1. 4,000 ft
2. 5,200 ft
3. 6,400 ft
4. 7,600 ft