Tigerfish Aviation is an aerospace research and development company based in Norwood, South Australia. Since the late 1990s, the company has been developing a retractable pontoon system for the float plane industry, which has been patented as Retractable Amphibious Pontoon Technology or RAPT.
The retractable float concept aims to reduce aerodynamic drag by folding the floats into a streamlined pannier under the fuselage of the aircraft. The reduction in drag improves performance of the aircraft and reduces its operating cost, such as fuel consumption. Reduction in drag also increases the range, payload, speed, and productivity of the aircraft. The drag reduction occurs due to the reduction of surface area exposed to the airstream and concealing the hydrodynamic features of the floats. It is designed as a retrofit, and is potentially capable of application to any existing aircraft. The technology has been applied on a one-sixth scale Cessna Caravan for concept-proving.
As of 2010, Dornier 228 NG is the first proposed aircraft to be retrofitted for the RAPT system, besides the small-scale Cessna. The retractable float system can be used in a wide range of aircraft including regional aircraft, utility aircraft, executive aircraft, military transports, VLJs, and UAVs. The University of Adelaide, with assistance of the South Australian Government, has performed CFD analysis and other studies on the DHC-6 Twin Otter showing that the RAPT system would result in a significant cost benefit. Unlike traditional floats, RAPT pontoons are made of lightweight composite materials, but suffer additional mass penalties due to the electric, hydraulic and structural systems required to retract the pontoons. Total mass penalty has been estimated at 1,420 pounds (640 kg) for a Dornier 228 NG variant.
- It's plane sailing for our engineering, University of Adelaide, April 2006
- CFD Analysis of the Tigerfish Retractable Float System on a DHC-Twin Otter