The last design by Bill Lear, he died before it was completed. His widow and employees finished the project in his honor, and 3 aircraft were built. A remarkable hybrid made almost entirely of composites, with twin turbo jet engines driving a single pusher prop. It had a top speed of 495 kts and a ceiling of 41,000 feet. By Mike Stone. 330K

This was posted in the download section.  I doubt that the lear fan ever got close to 495kts.  A LearJET couldn't even reach that speed.