Air Crash Investigations on YouTube (I wish that show was on Netflix), I decided to brush up on my waning skill set with my preferred aircraft, the Boeing 737-800. I have a couple of saved approach flights where I can load them to practice final approach and an ILS landing, as well as a full flight plan from Tampa to Miami, FL. After successfully running a scenario to simulate an ILS landing at Miami, I decided to do the full flight.
All was well until I received instructions to land at runway 30 in Miami, and I went through my notecard version of a checklist which included switching from GPS to NAV, and then engaging the Approach Hold to use the ILS glide slope to align with the runway. This was when all hell broke loose and the plane began an errant turn to the left and dived straight towards the Atlantic Ocean below (the approach to Miami from Tampa actually takes the planes out of the water on the east coast).
Not knowing what was going on, with both the sink rate and terrain warnings wailing away (“Pull Up! Pull Up!” will definitely grab your attention), I immediately disengaged autopilot and auto throttle, applied maximum thrust and began an 8 degree climb out of the danger all the while declaring a missed approach and asking for new vectors for another approach. After getting back altitude I reengaged the auto pilot and auto throttle and received clearance to land at runway 30 again.
It was at this point it dawned on me that I never entered the runway ILS frequency of 111.70 into the radio stack navigation 1 area, and did not set a course heading of 305 to align with the runway. So when I engaged the Approach Hold earlier, it went with whatever was programmed into the NAV1 area of the stack and was already on the course heading dial. In real life had I not recovered and this became an NTSB crash investigation, the flight data recorder would have captured my glaring error.