Patey did finally end up with the last Wilga 2000 to be produced, but he wasn’t happy with the underperforming stock O-540. Patey had already determined that the Wilga needed a more powerful engine when the 0-540 catastrophically failed one day, resulting in an off-airport landing in the desert. Stuck in the desert with a bad engine, Patey had all the motivation he needed to get started on his turbine Draco. He rebuilt the O-540 right there in the middle of the desert, flew the Wilga home, and began working on fitting Draco with a turbine engine. The PT6A would do. And he just happened to have one available.
Putting a turbine engine onto a Wilga wasn’t going to be easy. Switching from a certified aircraft type certificate to an experimental type certificate wasn’t a seamless process, and Patey says since he couldn’t get a standard experimental amateur build certificate, he applied for an experimental exhibition certificate, which allows him to exhibit at airshows but comes with another set of limitations. He had to build his own in-depth service manual, for example, and have it approved by the FAA. Not an easy task when you consider all of the individual modifications the airplane underwent. And an experimental exhibition certificate means that Patey is limited to what type of flying he can do. The exhibition certificate allows for the obvious air show flights, and it allows for training and proficiency flight, but it doesn’t necessarily allow him to fly Draco whenever he wants or without reason.
With a heavily modified airframe, this can hardly be called a Wilga anymore. Patey added five air filters, a new carbon fiber cowling and carbon fiber molds for cameras, including a night vision camera and back-up camera, which Patey says is helpful for backing into the hangar as well as formation flying and situational awareness on backcountry strips. Oxygen cannulas for all four seats allow for high-latitude flights, and additional fuel tanks in the gear legs not only provide additional fuel but also help lower the center of mass and allow for constant fuel flow even during unusual attitudes like forward slips – a problem he would have had with the standard fuel system. Patey lengthened the chord of the wing by a foot, enlarged the flaps and ailerons by 6 inches, and added different leading-edge cuffs, all of which he says took about 20 kts off the stall speed.