An amphibious or amphibian aircraft is an aircraft that can take off and land on either land or water. Amphibious aircraft are typically flying boats and floatplanes with retractable wheels.
An example of a true amphibious aircraft is the Grumman Mallard
, a flying boat
, designed and built in the mid 1940s. While floatplanes
sometimes have floats that are interchangeable with wheeled landing gear (thereby producing a conventional land-based aircraft), it is rare for a floatplane to successfully incorporate retractable wheels whilst retaining its floats; the Grumman J2F Duck
would be a notable example. In either case, such amphibious aircraft would require small floats to be fitted underneath the wings: while these impose additional drag and weight on all seaplanes, amphibious aircraft also face the possibility that these floats would hit the runway during wheeled landings. A solution would be to have the aircraft fitted with wing-mounted retractable floats: the Grumman Mallard
, for example, has retractable floats which also act as fuel tanks; these are removable for extended land/snow operations.
Amphibious aircraft are heavier and slower, more complex and more expensive to purchase and operate than comparable landplanes but are also more versatile. They do compete favorably, however, with helicopters
that compete for the same types of jobs, if not quite as versatile. Amphibious aircraft have longer range than comparable helicopters, and can indeed achieve nearly the range of land-only airplanes, as an airplane's wing is more efficient than a helicopter's lifting rotor. This makes an amphibious aircraft, such as the Grumman Albatross
and the ShinMaywa US-1
, ideal for long-range air-sea rescue tasks. In addition, amphibious aircraft are particularly useful as "bush" aircraft engaging in light transport in remote areas, where they are required to operate not only from airstrips, but also from lakes and rivers.
Amphibious aircraft have been built in various nations since the early 1920s, but it was not until World War II
that saw their widespread service. The Grumman
Corporation, a United States
-based pioneer of amphibious aircraft, introduced a family of light utility amphibious aircraft - the Goose
, the Widgeon
and the Mallard
- during the 1930s and the 1940s, originally intended for civilian market. However the military potential of these very capable aircraft could not be ignored, and large numbers of these versatile aircraft were ordered by the Military of the United States
and their allies during World War II, for service in air-sea rescue, anti-submarine patrol, and a host of other tasks. The concept of military amphibious aircraft was so successful that the PBY Catalina
, which began life as a pure flying boat, introduced an amphibian variant during the war.
The capabilities of these amphibious aircraft were found to be particularly useful in the unforgiving terrains of Alaska and northern Canada, where some remained in civilian service long after the war, providing remote communities in these regions with vital links to the outside world. Nonetheless, with the increased availability of airstrips and amenities in remote communities, fewer amphibious aircraft are manufactured today than in the past, although a handful of manufacturers around the world still produce amphibious aircraft (flying boats with retractable landing gear), such as the Bombardier 415, and the Lake Amphibian family.