To start flying can be very expensive. As the size of an airplane does affect the prices, we have a look at the smallest mini aircraft in the world today. All of the mini aircraft come with an engine and can be operated by a pilot. Some of the mini aircraft engine are in the ultralight aircraft category and some are even compliant with the Part 103 regulation which means you can fly those mini planes without a license in the US. We even found an insane small helicopter for the ones that are more interested in helicopters than in jet. With the twin Williams FJX-1 engines, the CMC Leopard had a top speed of 540 mph, not 345 (and this plane was designed in the 1980s). It had a pressurized cabin with a service ceiling of 55,000 feet and a climb rate of 6,340 feet per minute. With those specs, the plane could have flown coast to coast in about 4 hours. Unfortunately, due to suppliers going out of business, the project became stalled. Eventually, the owner of the project passed away, and it seems likely that this plane will never ever achieve commercial success. The Leopard is a fascinating mini-jet. If ever put into production, and if relatively affordable, it would surely attract buyers because with a range of up to 2200 miles it could, theoretically, be used to fly trans-oceanic North America to Europe, with a refuelling in Azores. My my my. Your own personal 2 or 4 seater affordable mini-jet.