When I was a kid, the Pitts Special was the pinnacle of aerobatic aircraft. Then, the arrival of a bunch of high-powered monoplanes like the Zlin Z50L showed up follow by Extras, and the Pitts became more the preserve of individuals getting into aerobatics. It can still make a good display platform, though, and plenty of souped-up versions are on the air show circuit. The Cosford show included one flown by Rich Goodwin that has been modified with a pair of turbine engines mounted on each side of the fuselage.
This makes for a lot of noise and plenty of extra power. The piston engine still does the majority of the work but, when going vertical, the jets are fired up and give a major boost in performance. That can include hovering in place if required. From some angles, the plane is hard to notice as being any different to any other Pitts. However, from the right angles, the engines are conspicuous. A pretty cool display act. I assume top speed is constrained by the original airframe limitations so not much point in using the jets unless pointing upwards.

