What type of visa do pilots who fly from one country to another need?
International Airline crews often spend 1 or 2 days laying over at the destination. In most countries, airline crew members who are listed on the Aircraft Customs and Immigration General Declaration are exempt from Visa requirements.
Rules will vary from country to country as to how much travelling freedom you have while staying in the layover country. Most countries require you to always have your passport with you and some countries require some kind of form identifying you as airline crew. Some countries have rules defining how far you can travel while on the layover.
In general practice most airline crews I know leave their passports in their room and just carry a photo copy or digital copy with them, and freely travel just as any tourist would do.