Performance is based on a mid CG with mid cabin and fuel weight on an average day. Performance should always be calculated per flight environment while referring to the Manufacturer’s Pilots Operating Handbook and applicable Flight Manual Supplements for the particular airplane. Aircraft Manufacturer’s Pilot Operating Handbooks and Aircraft Owner’s Manuals should always be available and adhered to by the aircraft Pilot in Command, including attention to applicable FAA approved Flight Manual Supplements and emergency procedures for each individual aircraft. Performance should vary from airplane to airplane, atmospheric day to atmospheric day, one gross weight and CG to another, and pilot to pilot.