The name, type, year of manufacture, and date of the next inspection are stored for aircraft. An aircraft performs several flights, the flight number and date of which are stored. 
Several passengers take part in a flight, and their names and passport numbers are stored. A passenger can take part in several flights. The (personalized) ticket for each flight is stored in the form of the ticket number and price. In addition, it is stored whether an upgrade is desired. 
Passenger aircraft are special aircraft used exclusively for the transport of passengers. The number of seats on these aircraft is also stored. 
A passenger aircraft can have several seat categories. The designation of each category is stored, whether or not it offers an entertainment program, and how many seats there are in this category. Each ticket is for a specific seat category.
Each aircraft can be part of an airline, whose name is stored. 
An airline employs several flight attendants and pilots. The name, date of employment, and whether the flight attendant is a chief steward or stewardess are stored for flight attendants. The name, date of employment, and license are stored for pilots.
Several flight attendants work on a flight. One pilot flies the aircraft as the captain and one or two other pilots act as co-pilots.
The name, address, and number of runways are stored for airports. Each aircraft can have a home airport. Each flight has a departure airport and a destination airport.