Reasons for the preflight inspection: 
Determine aircraft is legally airworthy 
Determine aircraft in safe condition for flight 
Items that should be inspected 
How defects are detected 
Importance of using the appropriate checklist 
How to determine fuel and oil quantity and contamination 
Detection of fuel, oil, and hydraulic leaks 
Inspection of the flight controls 
Detection of visible structural damage 
Removal of tie-downs, control locks, and wheel chocks 
Removal of ice and frost 
Importance of the proper loading and securing of baggage, cargo, and equipment 
Use of judgment in determining that the airplane is airworthy and in condition for safe flight.