Sometimes, while looking at airline timetables, I remember that some people actually have their own private jets. Sigh. Keeping the rest of us plebes in mind, a Montana inventor is at work on a new personal aircraft that's quiet, ultra-efficient and most important — affordable.

NEWS: Unmanned Airplanes Coming to a Terminal Near You

John McGinnis is a composite manufacturer in Kalispell, Mont., who has been interested in aeronautical engineering since he was in elementary school. More recently he's worked with his family on prototyping an aircraft called Synergy that just won a 2013 Popular Science Invention Award.

McGinnis, a member of the American Institute of Aeronautics and Astronautics, came up with an innovative “double-box-tail" design for the wings that's intended to increase efficiency and minimize drag. The aircraft is supposed to be three times as efficient as existing small aircraft and get more than 40 miles to the gallon. In addition, Synergy will have an impeller at the back rather than a propeller at the front, which should keep the noise lower.

Since his Synergy Aircraft design emerged several years ago, McGinnis and his project have piqued a lot of interest, including from NASA. This year, he hopes to produce a full-scale, five-person prototype of the aircraft using crowd-sourced funding. In the meantime, McGinnis and his family have a 1/4-scale model for testing. Although a projected price for the Synergy hasn't been set, the team says its goal is to create an aircraft that costs substantially less than ones currently on the market.

We recently reported on Terrafugia's efforts to develop a street-legal airplane, and there appear to be numerous challenges for McGinnis. And that's without any street concerns since he's not creating a flying car. A full-sized Synergy Aircraft will have a 32.4-foot wingspan and an overall height of 10.8 feet with the gear down. Even if a typical American family could afford to buy one, where will they store it?

Many other questions remain: How will this be regulated? Who's allowed to fly them? How will the air traffic be controlled? Maybe the Synergy aircraft will work best with a membership business model. It could be like owning a horse that stays on a ranch somewhere.

BLOG: 800-Pound Paper Airplane Soars High

Questions and challenges aside, McGinnis deserves kudos for his goals around affordability, accessibility and fuel efficiency. If only we could finally achieve all that for automobiles right now. Then, perhaps, it will make sense for the average American to start thinking about owning their own personal aircraft.

Image: A rendering of the design for Synergy. Credit: John W. McGinnis.