David's Modified Cessna 210 (550 Centurion)

Some are seeing a UFO at 5:14 in the video. OK I will add to the mystery.. The hour of the day put the sun almost directly into my camera lens. This video was recorded on a tripod a few feet inside the airplane hanger to keep the sun out of my lens. What ever it was was flying outside in the sun. Now that should give you a pause. I did not think anything about this until I started getting comments from people on YouTube. Someone will eventually solve the mystery. Most people think it is a bird, but if it is a bird it sure is flying 400 mph.David W. Hilsdon P.E.of Hilsdon Engineering Millington, Tennessee talkes about his modified Cessna 210

David mentions vortex generators in this video. This modification has increased the safety margin of airplanes. They improve short-field performance and low-speed handling. This is an addition to STOL modifications..