Regulations for aircraft are important for passenger and air crew safety. These regulations are instituted by governing agencies to improve the performance and safety of the airline industry. In the United States the airline industry is regulated by the Federal Aviation Administration, a part of the United States department of Transportation. In England, the governing body is the United Kingdom civil Aviation Authority. Every country is responsible for its own regulations for aircraft. In order to be efficient and encompassing regulations usually number in the tens of thousands and are very specific. For example, in the United States, the Federal Aviation Administration breaks its regulations into parts and then further breaks them down into sections. Part 91 is a specific regulation dealing with emergency situations and pilot responsibility. A subsection of this part, section 91.145 governs flight restrictions over certain areas and during certain times. Individuals in the airline industry must be familiar with the parts and sections that cover their level of expertise.