Each fuel system must—

Be designed and arranged to provide independence between multiple fuel storage and supply systems so that failure of any one component in one system will not result in loss of fuel storage or supply of another system;

Be designed and arranged to prevent ignition of the fuel within the system by direct lightning strikes or swept lightning strokes to areas where such occurrences are highly probable, or by corona or streamering at fuel vent outlets;

Provide the fuel necessary to ensure each powerplant and auxiliary power unit functions properly in all likely operating conditions;

Provide the flightcrew with a means to determine the total useable fuel available and provide uninterrupted supply of that fuel when the system is correctly operated, accounting for likely fuel fluctuations;

Provide a means to safely remove or isolate the fuel stored in the system from the airplane;

Be designed to retain fuel under all likely operating conditions and minimize hazards to the occupants during any survivable emergency landing. For level 4 airplanes, failure due to overload of the landing system must be taken into account; and

Prevent hazardous contamination of the fuel supplied to each powerplant and auxiliary power unit.

Each fuel storage system must—

Withstand the loads under likely operating conditions without failure;

Be isolated from personnel compartments and protected from hazards due to unintended temperature influences;

Be designed to prevent significant loss of stored fuel from any vent system due to fuel transfer between fuel storage or supply systems, or under likely operating conditions;

Provide fuel for at least one-half hour of operation at maximum continuous power or thrust; and

Be capable of jettisoning fuel safely if required for landing.

Each fuel storage refilling or recharging system must be designed to—

Prevent improper refilling or recharging;

Prevent contamination of the fuel stored during likely operating conditions; and

Prevent the occurrence of any hazard to the airplane or to persons during refilling or recharging.