B777, page-15

Hi Rosden,
Try this section:


In broad terms embodiments of the disclosed system and method rely on mass transfer of a fluid between at least two spaced apart galleries. In the absence of a fault the mass transfer can only occur via a crack that propagates between the galleries. Also an effect of the system and method is that the fluid which enters and flows along a crack persists whether or not the structure in which the crack is formed is under dynamic load or static load. Thus for example in structural monitoring of a component of an aircraft a crack which provides a flow communication path between two galleries when the aircraft is in flight (i.e. under dynamic load) should be detected by embodiments of the disclosed method and system when the aircraft is on the ground even though the crack may be fully closed under static load due to the presence of the fluid in the crack. This system is said to be bi-stable because it is designed to be stable in two modes. Compromised and uncompromised.