In the USA and Canada another category of aircraft exists called Amateur / Experimental built aircraft or vastly called the home built aircraft. In India, the DGCA has stipulated rules and regulations in the CAR for Operation of Amateur built Aircraft. Refer to the link below for Indian regulations pertaining to Amateur built Aircraft.
Details regarding special certificate of Airworthiness and maintenance regulations of Amateur built aircraft are in the below link.
Amateur built Aircrafts can be built using the 49 % kits supplied by Aircraft kit manufacturing companies, or using their design plans only called the Scratch built, where the builder uses only the design and plans supplied by Aircraft companies to build the aircraft, the raw material is purchased locally from approved vendors, so that the MSDS of material used can be verified, which is required for registration. The building time in scratch build is much more than that when built using a 49% Kit, but the cost of the aircraft is reduced appreciably, In the USA and Canada, engines used on these aircrafts may be certified aircraft engines, non certified engines or even Automotive engine conversions like Honda, Suzuki, Subaru, Corvair, BMW, etc, these used engines core are pretty cheap and after overhaul and conversion are appreciably reliable.
The experimental built aircraft project is generally taken over by aviation enthusiasts and the financially stable persons in the USA, this keeps them occupied for long period and also have a satisfaction they have accomplished a major task.
One can Scratch build and fly a two seat Zenith 701, an all metal aircraft with basic VFR instruments using Automotive conversion engine for less than 15 lac Rs. What more economy one can expect than owning an Amateur built Aircraft for this little price.
A kit built or Scratch built project may extend for years, depending upon the time the individual builder can devote. Generally a Zenith CH 701 kit requires 1500 hrs to build. This means, if an individual works for 5 hrs a day on his aircraft project, He shall be able to complete the aircraft in less than one year. The plans and drawings are very easy to understand and even a layman can use the basic tools and accessories provided with the kit. No particular skill is required to build the aircraft. More over there are lot of videos available on youtube on aircraft building techniques.
We at Jai Aviation have a team of experienced technicians and assistants and have builders assist program, our team guides the individuals building their airplane so that the time is reduced to 1/3 of the original as depicted by the company. We also take care of the record keeping and documentation required by the DGCA for the aircraft registration.
We at Jai Aviation are presently working on a zenith 701, the airframe is almost complete, wings, control surfaces and tail are ready, fuselage 80% done and we intend to use a 2001 model Honda City 1.5 EXI car engine. This engine is all aluminum, light weight, liquid cooled, 4 cylinder, 4 stroke, fuel injected and delivers 100 HP, which is sufficient for this kind of aircraft performance and even this is recommended by the company. The engine has been stripped, checked of any deterioration and all the seals piston rings and are being replaced. The intake and exhaust valves have been re seated. Now we are designing the reduction gear which shall be a belt drive with 2.89:1 ratio and will be fabricated here in our workshop using 6061 T6 aluminum and chrome-moly steel alloys. Hopefully in a few months we shall be trying out the engine on bench and then installed on the fuselage.
Complete list of Amateur Built aircraft kits approved by FAA (Federal Aviation Authority) follow the link