Learjet 25C 8.4 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. This Mac app is an intellectual property of AIR.C74.NET.
From the developer:
Presenting what I feel to be the highest caliber transport category corporate jet ever available for x-plane. Meticulously produced from authentic original factory orientation and information manuals, plus the standard regime of FAA data sheets, this aircraft properly and exactly represents this classic corporate jet.
This model wonderfully captures the essence of the early 70's vintage, while feeling like a powerful, sophisticated modern jet.