Did you know that every airplane has an identifying number on it? The tail number tells you where it is registered, and the identification of the plane itself. You can look these up online. Every country has their own numbers. Every airplane that flies - including private planes, experimentals, and ultralights - have a tail number.

Airventure. Photo courtesy of flickr Creative Commons: flickr.com/photos/loimere/2736970464/

Aficionadoes (especially Europeans) are called tail number spotters, and collect tail numbers from planes. They also collect the date of the spotting, and where they saw it. These are maintained in a log.  This is a big hobby - there are many enthusiasts, and they have clubs and organizations. Many travel all over the world, as much as they can, to spot tail numbers. Distance is no object! Tail number spotters often assist airport security in noticing things that are out of the ordinary or suspicious.

If you're a Tail Number Spotter, you'll want to head to Airventure, by the Experimental Aircraft Association. It's a great place to gather tail numbers for your collection. Held at the end of July, Airventure lasts for a week, and is located in Oshkosh, Wisconsin. There are over 2400 aircraft there. During that week, the Oshkosh airport becomes the busiest airport in the world. Airport parking is at a premium! It's the world's largest aircraft flyin.

People fly in antique airplanes, military aircraft, private planes, and large commercial planes. There are skydivers, parachutists, ultralights, acrobatic aircraft, and more.

Airventure

A military plane C-5 may fly over, to show the maneuverability. The C-17 (a big cargo plane) may land and demonstrate how they can do short takeoffs and landings. 40-50% of the flying C47s (twin engine cargo plane from WWII) are at the EAA.  People spend thousands of dollars to fly their planes there and participate.

If you're a tail number spotter, Airventure is the closest you'll get to heaven. Fill your log books!