Determination of electrostatic discharge hazard in aircraft refueling operations by evaluation of plastic tank filling

Electrostatic discharge during aircraft refueling has long been recognized as a safety hazard. The need to minimize the possibility of this phenomenon has led to the development of different practices, the most common of these being the addition of a static dissipator additive (SDA). Nowadays, the SDA is a well-established requirement in all leading jet-fuel specifications, and it is in widespread use in commercial and military aviation. Despite this, Israel’s Air Force (IAF) has rarely used SDA over the course of its existence; fortunately, without any recorded safety events related to electrostatic discharge in the hundreds of thousands of refueling operations that have been carried out in the IAF. In order to deepen the understanding of the electrostatic behavior, an insulated plastic cylindrical tank was filled with different configurations and fuel conductivities, while recording the electrostatic field outside the tank. The results showed that the electrostatic risk of fueling with non-conducting jet-fuel in the IAF`s aircraft fueling system is not high enough to justify the addition of SDA. The method developed in this research is simplified and does not require complicated instruments, while providing the information required for the operator to decide on the necessity of the SDA.