A private pilot's license in the U.S. can be applied for if one is above 16 years of age and is generally keeping healthy. The basic license allows flying a single engine aircraft alone as well as carrying passengers in it.

A second engine increases the safety factor so that a multi engine aircraft can stay in the air even after one engine has failed accidentally, and thus provides an important safety margin especially when the flight is crossing over water or hilly region.

A helicopter is an aircraft that is lifted in the air and propelled forward by one or more horizontal rotors. These rotors are made of two or more rotor blades. Helicopters are classified as rotorcraft or rotary-wing aircraft as different from fixed-wing.

In the late 70s and early 80s, there was a public pressure from the affluent class who wanted to fly on their own. Hence came a new category of aircraft known as microlight or ultralight aircraft - a slow-flying airplane free from strict regulation!

When they are first designed and flown, most of the aircraft are marked as experimental aircraft at least for their first few flights. They are the tools for new exploration and new discoveries in the field of aviation.

When it comes to general aviation, there are two kinds of flights - the private flights and the commercial flights. Private pilots fly an aircraft basically for personal travel, or their business travels, or else just for fun.