AirplanePDQ 9.3.3 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The actual developer of the program is DaVinci Technologies, Inc. The program is included in Education Tools. We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software.
From the developer:
AirplanePDQ is a conceptual/preliminary design tool for light homebuilt and general aviation aircraft. It is specifically designed to be intuitive and easy to use by amateur airplane designers. AirplanePDQ includes tools for analyzing aircraft performance, handling, and stability and control as well as a CAD component for developing your aircraft drawings. Initial airplane sizing is done rapidly using a wizard-based approach.
You may want to check out more software, such as Whizlabs PMP, RhymeTime5 or Internet TRiLOGI Educational, which might be related to AirplanePDQ.