A LOW-COST TWIN-engined amphibian aircraft based on the Pilatus Britten-Norman (PBN) Islander is being developed by a new UK aircraft company.

Ross Aircraft has already successfully tested a one-fifth-scale model in proof-of-concept trials on a Scottish lake and is in negotiations with potential backers in a bid to secure the $7 million needed to take a full-scale prototype through certification and into early production.

The work, supported by PBN, revives a design undertaken years ago by US amphibian authority David Thurston - who was involved in various seaplane designs, including that of the Grumman Mallard. Thurston Aeromarine is responsible for all design work.

For the pre-production certification work, Ross Aircraft plans to acquire a second-hand Islander and modify the fuselage by attaching a hull glove, raising the engines above the wing, fitting a larger dorsal fin, removing the wheels and adding wing floats. The UK Civil Aviation Authority has told Ross that, for certification, it will consider the aircraft as a major modification to the Islander.

For production, Ross Aircraft is expected to buy in kits from PBN supplier Romaero of Romania, for modification at a factory in Scotland.

Production aircraft would have two Lycoming TIO-540 engines with counter-rotating three-bladed propellers, a retractable main landing gear and steerable locking tailwheel and, possibly, the wing from the newly certificated Defender 4000, which is longer and stronger than the Islander wing. Ross chief executive Kenn Heely says that the company has not decided whether to go for the 3,600kg gross weight which the new wing would give it or to use a re-stressed standard wing with 3,350kg gross weight.

Heely estimates that the aircraft, with a range of over 1,600km (860nm) and carrying up to nine passengers, can be built at half the cost of second-hand twin-engined seaplanes.


Source: Flight International