Chapter $3$ database systems, problems, number $27$ modify the ERD created and problem $25$ to eliminate the problems created by the use of synonyms $($hint : Modify the charter table structure by eliminating, the char pilot and the charcoal pilot attributes, then create a composite table named crew to link the charter and employee tables. Some crewmember such as flight attendants may not be pilots. That's why the employee tables enter into this relationship.