You are planning the ILS or LOC RWY 21 approach into Flagstaff, AZ. Using only certified GPS equipment, can you fly this approach? nybtvrce.PNG Group of answer choices No, I must be using navigation equipment capable of picking up the localizer and VOR frequencies in the area. I can only use GPS to aid in distance measuring on this approach. Yes, the only certified GPS receivers can be used to fly ILS or LOC approaches. I can use GPS to fly to the VDP, but need to use VOR nav equipment to proceed from there on