Problem $1$: You are hired to design a database that keeps the information about an airport, all the

airplanes stationed and maintained in it as well as its employees. The relevant information is

described below:

Every airplane has a registration number and a company name $($the company that operates it$,$ say

Delta, JetBlue, etc.$)$ There are various airplane models, and each model is identified by a model

number $($Airbus $350,$ Boeing $777$ etc.$),$ has a seat capacity, a weight and type of fuel. Each

airplane is associated with a specific model.

There are two types of employees in the airport: technicians and traffic controllers. Each

employee is uniquely identified by their social security number. All airport employees belong to

a union, so you must store the union membership number of each employee. In addition, $($i$)$ for

technicians you must store their last$\_$name. their address, phone number, and salary, $($ii$)$ for

traffic controllers we want to keep their age and years of experience.

Every traffic controller must pass at least one efficiency exam before they are allowed to work at

the airport. Each such exam is identified by its level. You should also record the exam$$s duration

and date. Traffic controllers can take more exams if they want to improve their efficiency.

A technician has the knowledge to fix at least one airplane model$($s$).$ Some technicians can fix

many models. An airplane model can be fixed by more than one technician but there are no

models that cannot be fixed by some technician.

The airport has a number of tests that are used periodically to ensure that airplanes are still

airworthy. Each test has a Federal Aviation Administration $($FAA$)$ test number, a name, and a

maximum possible score.

The FAA requires the airport to keep track of each time a given airplane is tested by a given

technician using a given test. For each testing event, the information needed is the date, the

number of hours the technician spent doing the test, and the score the airplane received on the

test.