CS-VLA 967  Fuel tank installation

ED Decision 2003/18/RM

(a)                            Each fuel tank must be supported so that tank loads are not concentrated. In addition -

(1)                            There must be pads, if necessary, to prevent chafing between each tank and its supports;

(2)                            Padding must be non-absorbent or treated to prevent the absorption of fuel;

(3)                            If flexible tank liner is used, it must be supported so that it is not required to withstand fluid loads;

(4)                            Interior surfaces adjacent to the liner must be smooth and free from projections that could cause wear, unless -

(i)                             Provisions are made for protection of the liner at those points; or

(ii)                            The construction of the liner itself provides such protection;

(5)                            A positive pressure must be maintained within the vapour space of each bladder cell under all conditions of operation except for a particular condition for which it is shown that a zero or negative pressure will not cause the bladder cell to collapse; and

(6)                            Siphoning of fuel (other than minor spillage) or collapse of bladder fuel cells may not result from improper securing or loss of the fuel filler cap.

(b)                            Each tank compartment must be ventilated and drained to prevent the accumulation of flammable fluids or vapours. Each compartment adjacent to a tank that is an integral part of the aeroplane structure must also be ventilated and drained.

(c)                            No fuel tank may be on the engine side of the firewall. There must be at least 13 mm of clearance between the fuel tank and the firewall. No part of the engine nacelle skin that lies immediately behind a major air opening from the engine compartment may act as the wall of an integral tank.

(d)                            If a fuel tank is installed in the personnel compartment it must be isolated by fume and fuel-proof enclosures that are drained and vented to the exterior of the aeroplane. A bladder type fuel cell, if used, must have a retaining shell at least equivalent to a metal fuel tank in structural integrity.

(e)                            Fuel tanks and fuel system components must be designed, located, and installed so as to retain fuel -

(1)                            Under the inertia forces prescribed for the emergency landing conditions in CS-VLA 561; and

(2)                            Under conditions likely to occur when an aeroplane lands on a paved runway at a normal landing speed under each of the following conditions:

(i)                             The aeroplane in a normal landing attitude and its landing gear retracted.

(ii)                            The must critical landing gear leg collapsed and the other landing gear legs extended.