CS 22.893  Water ballast tank installation

CAA ORS9 Decision No. 1

(a) General. The surrounding aircraft structure must be appropriately protected from any likely damage (corrosion, debonding, etc.) from water ballast leaks. 

(b) Water ballast tanks which are not an integral part of the structure must be supported so that the loads resulting from the mass of the water ballast are not concentrated. In addition: 

(1) Means must be provided to prevent chafing between each tank and the supporting structure. 

(2) Each tank compartment must be vented and drained 

(c) For integral tanks the surrounding structure must either be shown to be impervious to ballast absorption, or suitably protected.