Curtiss SO3C Seamew

The Curtiss SO3C Seamew was developed as a replacement for the SOC Seagull as the United States Navy’s standard floatplane scout.

Curtiss named the SO3C the Seamew but in 1941 the US Navy began calling it by the name Seagull, the same name as the aircraft it replaced (the Curtiss SOC a biplane type), causing some confusion.

The British Royal Navy kept the Curtiss name, Seamew, for the SO3Cs that they ordered.

One of the US Navy’s main design requirements was that the SOC Seagull’s replacement had to be able to operate both from ocean vessels with a single centre float and from land bases with the float replaced by a wheeled landing gear.

From the time it entered service the SO3C suffered two serious flaws: inflight stability problems and problems with the unique Ranger air-cooled, inverted V-shaped inline engine.

The stability problem was mostly resolved with the introduction of upturned wingtips and a larger rear tail surface that extended over the rear observer’s cockpit.

The additional tail surface was attached to the rear observer’s sliding canopy and pilots claimed there were still stability problems when the canopy was open; the canopy was often open because the aircraft’s main role was spotting.

While the in-flight stability problem was eventually addressed (although not fully solved), the Ranger XV-770 engine proved a dismal failure even after many attempted modifications.

Poor flight performance and a poor maintenance record led to the SO3C being withdrawn from US Navy first line units by 1944.

The older biplane SOC was taken from stateside training units and restored to first-line service on many US Navy warships until the end of World War II.



Prototype, one built originally as a landplane and later modified as a floatplane.


Production variant, 141 built.


SO3C-1 aircraft modified as target drones, some to the Royal Navy as the Queen Seamew I.


Similar to SO3C-1 but with arrester gear, landplane variant could be fitted with a ventral bomb rack, 200 built.


Lend-lease variant of the SO3C-2 with improved radio and 24V electrical system, for the Royal Navy as the Seamew I, 259 ordered but only about 59 were built.


Reduced weight variant with detailed improvements and catapult operation ability removed, 39 built with a further 659 cancelled.


Proposed variant of the SO3C-3 with arrester hook and catapult capable, not built.


Lend-lease variant of the SO3C-4 for the Royal Navy as the Seamew II, not built.





36 ft 10 in (11.23 m) seaplane 

34 ft 2 in (10.41 m) landplane


38 ft 0 in (11.58 m)


15 ft 0 in (4.57 m)

Wing area

290 sq ft (27 m2)

Empty weight

4,284 lb (1,943 kg)

Max take-off weight

5,729 lb (2,599 kg)


1 × Ranger V-770-6 inverted V-12 air-cooled piston engine,

600 hp (450 kW)


2-bladed constant-speed propeller


Maximum speed

172 mph (277 km/h, 149 kn)

Cruise speed

123 mph (198 km/h, 107 kn)


1,150 mi (1,850 km, 1,000 nmi)


8 hours

Service ceiling

15,800 ft (4,800 m)

Wing loading

19.8 lb/sq ft (97 kg/m2)


0.10 hp/lb (0.16 kW/kg)



1× 0.30 in (7.62 mm) forward firing M1919 Browning machine gun 


1× 0.50 in (12.7 mm) M2 Browning machine gun in rear cockpit.


2× 100 lb (45 kg) bombs or 325 lb (147 kg) depth charges underwings.

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