SAE AIR 5691A:2017 pdf free

SAE AIR 5691A:2017 pdf free.Guidance for the Design and Installation of Fuel Quantity Indicating Systems
FAULT: A failure of an in-tank or outside tank component, including wiring, which contributes to the posibility of creating an ignition source or impacts gauging accuracy (e.g., the shorting of a fuel probe by a contaminant).
GROUND: A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth or to some conducting body that serves in place of the earth. ARP1870 defines a ground as “A conducting connection, whether intentional or accidental, by which an electric current or equipment is connected to the earth, or to a conducting structure that serves a function similar to an earth ground (that is, a structure such as a frame of an air, space, or land vehicle that is not conductively connected to earth).”
QUALITATIVE: Those analytical processes that assess system and airplane safety in a subjective, or objective, but non-numerical manner.
QUANTITATIVE: Those analytical processes that apply mathematical methods to assess system and airplane safety.SHIELD: The practice of surrounding conductors, cables and electronics with conductive or magnetic materials to guard incoming or outgoing emissions of electromagnetic frequencies. In the case of a capacitance fuel gauging system harness, the HiZ conductor is enclosed in a shield and the harness to a sensor maybe enclosed in a 2nd shield depending on the electromagnetic environment. Also referred to as a SCREEN.
FAIL-SAFE DESIGN: 14 CFR/CS S25.981 paragraph a(3) defines a fail-safe design as “Demonstrating that an ignition source could not result from each single failure, from each single failure in combination with each latent failure condition not shown to be extremely remote, and from all combinations of failures not shown to be extremely improbable.” Within the context of 14 CFR/CS S25.1309, an extremely improbable event (catastrophic) is defined as having a probability 0 less than 10-9 per flight hour. Within the context of 14 CFR/CS S25.1309, an extremely remote event (severe major) is defined as having a probability of less than 10-7 per flight hour.SAE AIR 5691A pdf free download.