Given the information below, create the fully labeled Crow's Foot ERD using a specialization hierarchy where appropriate (use Visio). The ERD must contain all primary keys, foreign keys, and main attributes. Business rules are defined as follows: .

a. The Aircraft Maintenance department performs all maintenance for company's aircraft. The company classifies its' employees as Mechanics, Administrators, or Staff.
b. For each employee, the company wants to keep track of his/her ID, first and last name, and salary. In addition, some employees have different attributes. The list of such attributes includes but is not limited to the following: the classification level for mechanics, the position for administrators, and the hourly rate for staff must be recorded. For mechanics performing engine maintenance, the date of their last refresher course must be recorded.
c. For mechanics performing airframe maintenance, the number of years of experience must be recorded.
d.. For mechanics performing avionics maintenance (avionics are the electronic components of an aircraft that are used in communication and navigation), the access level must be recorded.
e. Each employee generates a record in the YEARS table that keeps track of the total number of years an employee worked for the company.
f. The table also includes the "COMMENT field where any additional information may be recorded. One record is related to . one employee only