In practice that is difficult to do on most BASE jumps as you need to sustain a steep angle for 10-15 seconds to hit that speed. Density altitude will greatly affect performance as well.
What's cool is being able to sustain 180mph while not losing altitude, which it sounds like BMW+Salzmann have accomplished. From the article:
"While Salzmann’s first flight was a resounding success, it appears he’s not resting on his laurels. According to BMW, the daredevil wants to fly between the skyscrapers of South Korea next."
I've dreamed of being able to zigzag through downtown skyscrapers for more than 10-15 seconds. The Jetman project is astounding. From a friend who is working on a copycat, the costs are close to 100k to replicate. Eager to see experimentation+progress on any projects with the promise of making hybrid human+wing flight more accessible (cheaper).
To maintain level flight they need to generate a lot more lift, while carrying the extra weight of an engine. By comparison a 747 has a glide ratio of 15:1 and depending on specific model and how much weight it has onboard it will stall in level flight around 180MPH. While many aircraft can fly at much lower speeds, a wingsuit is a terrible aircraft.
The article itself mentions typical horizontal speeds of around 62 mph.
The Wikipedia article on wingsuit flying says:
> A typical skydiver's terminal velocity in belly to earth orientation ranges from 180 to 225 km/h (110 to 140 mph). A wingsuit can reduce these speeds dramatically. A vertical instantaneous velocity of 40 km/h (25 mph) has been recorded. However the speed at which the body advances forward through the air is still much higher (up to 100 km/h [62 mph]).
Even mentions another jetpowered attempt with hydrogen peroxide rockets reaching a horizontal speed of 160 mph, back in 2007.
https://en.wikipedia.org/wiki/Wingsuit_flying