A Fluidically Controlled Aircraft Fuel Transfer System

Traditional methods of electrical sensing and control in jet aircraft fuel transfer systems have proven expensive, hard to maintain, and sometimes unreliable. This paper presents a new concept in fuel sensing and control using fluidics. The objective was to construct a general three-tank model system for exploring concept feasibility. Although a single medium (fuel) approach was sought, the interim model used a pneumatic logic and sensing system for fuel control. The laboratory model effectively demonstrated fuel level control, diversion of fuel transfer at the command of an automatic logic system, and pilot override. A trade study showed gains in reliability and maintainability over the current method of aircraft fuel transfer control. Advantages were: no dependence on electric or hydraulic power, ease of maintenance, and fail-safe operation.