Analysis of an in-flight water refilling system for single-engine fire bombing aircraft

Abstract

This thesis will analyse the viability and safety of an in-flight water refilling system which was originally designed and tested by an Australian in 2007. The design in question consisted of a ski/scoop mechanism which was attached to the aircrafts fixed undercarriage. Currently the only system that exists worldwide for filling such an aircraft is the modification and addition of after-market floats. These cost in excess of $1M and significantly reduce the aircrafts’ useful payload, range and manoeuvrability which have the overall effect of reducing both the capability and performance. Designing a more efficient, cheaper system has vast potential particularly in fire-prone countries. In order to assess the safety and viability of this design, extensive theoretical calculations have been compared to real-world experimental data in order to come to an accurate result of the forces and moments acting on this aircraft during the refilling process. These have then been compared with data calculated from a control surface analysis, in order to determine the aircrafts controllability in this flight condition. The final outcome is that this system, although theoretically possible in the sense of aircraft controllability under certain conditions, is not safe for the intended purpose on aircraft.