Supermarine Seagull (1921)

infobox Aircraft
name = Seagull
type = Reconnaissance flying boat
manufacturer = Supermarine


caption =
designer =
first flight = May 1921
introduced =
retired =
status =
primary user = Fleet Air Arm
more users = Royal Australian Air Force
produced = 1922-1933
number built = 34
unit cost =
developed from = Supermarine Seal
variants with their own articles =

The Supermarine Seagull was a British amphibian biplane flying boat developed from the Supermarine Seal by the Supermarine company. The Seagull was constructed of wood. The lower wing was set in the shoulder position and had two bays. The engine was mounted in a nacelle slung from the upper wing and powered a four-blade propeller in tractor configuration. The fuselage had an oval cross-section and had a planing bottom with two steps.

Design and development

The prototype, which became known as the Seagull Mk I, was modified from an existing Supermarine Seal II in 1921. Only one aircraft was made. A Napier Lion II engine was fitted and there were modifications made to the nacelle.

Produced from 1922, the production aircraft, the Seagull Mk II, had a Napier Lion III engine, and these were supplied to the Air Ministry and Royal Navy. A total of 25 were built, although some of these were later modified.

The Seagull Mk III was the Australian version, built in 1925. These were similar to the Seagull II but with a Napier Lion V engine and radiators modified for tropical use. Six of these were supplied to the Royal Australian Air Force, and one other Seagull III was built for Japan.

One Seagull II was rebuilt and fitted with Handley-Page leading edge slots and twin fin and rudders in 1928. This was considered to be the Mark IV, although Supermarine never designated it as such. Three ex-service aircraft were later placed on the British Civil Register.

One additional aircraft was built in 1933, using a Bristol Jupiter IX engine in the pusher configuration. This became known as the Seagull V and was the forerunner of the Supermarine Walrus.

Operational history

The type was used operationally as a fleet spotter. The Seagull II was the first British aircraft to be catapult launched in 1925. The crew was normally three (Pilot, Observer, and Radio-Operator). The sole armament was a .303 Lewis gun.

Operators

;AUS
*Royal Australian Air Force received 6 six aircraft.
**No. 101 Flight RAAF;JPN
*Imperial Japanese Navy Air Service received 1 aircraft.;UK
*Fleet Air Arm received 26 aircraft.

pecifications (Seagull I)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Fact|date=February 2008
crew=Three (pilot, wireless operator & gunner)
capacity=
payload main=
payload alt=
length main= 34 ft 6 in
length alt= 10.52 m
span main=48 ft 11 in
span alt=14.91 m
height main= 18 ft 6 in
height alt=5.64 m
area main= 605 ft²
area alt=56.22 m²
airfoil=
empty weight main= 3,691 lb
empty weight alt= 1,677 kg
loaded weight main= 5,462 lb
loaded weight alt= 2,482 kg
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=

engine (prop)=Napier Lion II
type of prop=12-cylinder water-cooled W-block piston engine
number of props=1
power main= 450 hp
power alt=336 kW
power original=

max speed main= 80 mph at sea level
max speed alt= 130 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main=
range alt=
ceiling main= 9,000 ft
ceiling alt= 2,745 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
*Endurance: 3½ hours
armament=
* 1 × .303 Lewis gun
avionics=

pecifications (Seagull II)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Fact|date=February 2008
crew=Three (pilot, wireless operator and gunner)
capacity=
payload main=
payload alt=
length main= 37 ft 9 in
length alt=11.5 m
span main=46 ft
span alt=14.02 m
height main= 14 ft
height alt=4.26 m
area main= 593 ft²
area alt=55.11 m²
airfoil=
empty weight main= 3,820 lb
empty weight alt= 1,736 kg
loaded weight main= 5,691 lb
loaded weight alt= 2, 586 kg
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=

engine (prop)=Napier Lion III
type of prop=12-cylinder water-cooled W-block piston engine
number of props=1
power main= 492 hp
power alt= 367 kW
power original=

max speed main= 85 mph at sea level
max speed alt= 138 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main=
range alt=
ceiling main= 9,150 ft
ceiling alt= 2,790 m
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
* Endurance: 4½ hours
armament=
* 1 × .303 Lewis gun
avionics=

ee also

Aircontent
related =
* Supermarine Walrus
similar aircraft =
lists =
* Seaplanes and flying boats
* Aircraft of the: Japanese Navy· Fleet Air Arm· RNZAF and RNZN
see also =

References

Notes

Bibliography

* Andrews, C.F. and Morgan, E.B. "Supermarine Aircraft Since 1914". London: Putnam Books Ltd., 2nd revised edition 2003. ISBN 0-851-77800-3.
* Brown, David. "Supermarine Walrus I & Seagull V Variants". "Aircraft in Profile, Volume 11". Windsor, Berkshire, UK: Profile Publications Ltd., 1972.
* Kightly, James and Wallsgrove, Roger. "Supermarine Walrus & Stranraer". Sandomierz, Poland/Redbourn, UK: Mushroom Model Publications, 2004. ISBN 83-917178-9-5.

External links

* [http://www.britishaircraft.co.uk/aircraftpage.php?ID=196 British Aircraft Directory]