Vietnam is buying six Canadian DHC-6 400 Twin Otter Amphibian aircraft. This is a 5.6 ton, twin engine, propeller driven aircraft, equipped with pontoons so they can operate from the water. It has a 21 meter/65 foot wingspan, and is 16.8 meters/52 feet long. The Twin Otter can carry up to 20 passengers, but Vietnam is going to equip them with radar and use them for maritime surveillance (along 3,500 kilometers of coastline). For these missions, the DHC-6 can stay in the air about six hours per sortie.