Most countries are member of the International Civil Aviation Organization (ICAO) and as such have signed the "Chicago Convention 1944" (111 pages, 2 Mb). Aviation rules and regulations in member countries are based on the recommendations of the ICAO.
This is necessary to get a certain guaranteed worldwide standard for airspace, airports, crew licensing and other important aviation safety related matters. These recommendations are published by ICAO in Annexes and Documents. Member countries should then process the recommendations in their aviation law and regulations and make these available to interested parties in paper or electronic form.
Pilots are expected to know the law concerning their flight, aircraft and other regulations of the country they fly in or over. And that can be a challenge if your flight takes you through many countries, easily done in large continents with a lot of relatively small countries like Europe and Africa.
Rules and information which might be of interest to the experimental aircraft pilot are listed here. For original text and content check with the original publisher of the information.
From AVweb Nov 8, 2009:
"The FAA's special review of the Zodiac CH601XL and CH650 has implicated "several areas of concern" within the aircraft design that may couple with operational aspects to cause in-flight structural failures. EAA is now urging operators to not fly the aircraft until operators comply with a forthcoming Safety Directive/Safety Alert from the Zodiac's manufacturer. The FAA determined that stick force characteristics, airspeed calibration, structural stability, wing structure and flutter all conspire to the detriment of the designs overall safety. The agency studied five in-flight structural failures in the U.S. involving two S-LSA aircraft, one E-LSA experimental, and two experimental Zodiacs."
Update Nov 14, 2009, due to another in-flight break-up on Nov, 6:
"Mandatory grounding aside, Zenith (manufacturer of the aircraft kits), the FAA and the EAA have all recommended that all Zodiac CH-650 and CH-601XL aircraft remain grounded until modified, regardless of their certification status."
For more information we advise CH650 & CH601XL owners to contact Zenith Aircraft and read about it in Special Airworthiness Information Bulletin CE-10-08.
As of March 2008 any pilot with a PPL license or higher is required by ICAO to obtain Language Proficiency Endorsement with his Radio Telephony license. This is to make sure that the level of English used by pilots on the radio is of a required standard. All pilots with a RT license obtained before March 2008 will get a LPE level 4 automatically when they renew their license and this LPE-4 is valid for 3 years (until March 2011). A LPE-5 is valid for six years and a LPE level 6 is a lifetime endorsement and needs no renewal.
Read ICAO Doc 9835/AN453 (149 pages, 1 Mb) for more info.
As of July 2008 its mandatory by ICAO to carry an Emergency Locator Transmitter (ELT) operating on 406 MHz on all International GA flights. The old ELTs (121,5 and 243 MHz) will not be monitored anymore by CORPAS/SARSAT satellites as of Feb, 1st 2009.
Transport Canada has decided to mandate the new ELTs for most aircraft flying in Canadian airspace, private and foreign aircraft too. Make sure to comply when the rules goes into effect somewhere summer (2010), read more about that in the Canada Gazette Part II.
If you are flying a vintage aircraft, experimental or not, you must take note that the US-FAA has published AC 23-27 which details guidance to both owner and or restorers and FAA aviation safety inspectors when collecting information needed for a FAA approval. This is necessary when parts or materials used in the original construction of the type-certificated airplane are no longer available, or newer, more appropriate materials are now common and would be more appropriate to be used when repairing or replacing components.
Read all about it in FAA AC 23-27 Vintage Aircraft.