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Curtiss Model 18

The Curtiss 18T, unofficially known as the Wasp and by the United States Navy as the Kirkham, was an early American triplane fighter aircraft designed by Curtiss for the US Navy.

The Curtiss 18T was intended to protect bombing aircraft over France, and a primary requisite for this job was speed.

Speed was not the triplane’s only salient feature: an 18T-2 set a new altitude record in 1919 of 34,910 ft (10,640 m).

The streamlined and very “clean” fuselage contributed to the aircraft’s performance.

The basic construction was based on cross-laminated strips of wood veneer formed on a mould and attached to the inner structure.

The technique was a refinement of that used on the big Curtiss flying boats.

Flown by Roland Rholfs, the 18T achieved a world speed record of 163 mph (262 km/h) in August 1918 carrying a full military load of 1,076 lb (488 kg).

The Model 18T-2 was an improved version of its predecessor, with 50 additional horsepower.

The wings of the new model were swept back.

It was also 5 ft (150 cm) longer with a 9 ft (270 cm) larger two-bay wing, though its operational ceiling was 2,000 ft (610 m) lower.

After World War I, it was employed as a racing plane: an 18T-2 nearly won the Curtiss Marine Trophy Race in 1922 (limited to U.S. Navy pilots), but the pilot, Lt. Sanderson ran out of fuel just before the finish line.

Curtiss Engineering followed the Model 18T with the Model 18B, unofficially known as the “Hornet”, built to otherwise similar specifications.


Model 18T or 18T-1

Two-seat fighter triplane with single-bay wings, powered by a 400 hp (300 kW) Curtiss K-12 piston engine.

Referred to by the US Navy as the “Kirkham”.

Originally designated 18T, the type was redesignated the 18T-1 when the prototype was modified to a new configuration designated 18T-2.

Model 18T-2

18T with longer-span two-bay wings.

Could be fitted with floatplane or landplane landing gear.

Model 18B

Biplane fighter version, known unofficially as the “Hornet”.

Sole flying prototype of Curtiss 18B, USAAS 40058, ‘P-86’, crashed early inflight trials at McCook Field, Dayton, Ohio, summer 1919.

Type not ordered into production.

One non-flying prototype also delivered for static testing.





23 ft 4 in (7.11 m)


32 ft 0 in (9.75 m)


10 ft 2 in (3.10 m)

Wing area

288 sq ft (26.8 m2)



Empty weight

1,980 lb (898 kg)

Gross weight

3,050 lb (1,383 kg)


1 × Curtiss K-12 V-12 water-cooled piston engine,

400 hp (300 kW)


2-bladed fixed-pitch propeller


Maximum speed

163 mph (262 km/h, 142 kn)


5 hours 54 minutes

Service ceiling

23,000 ft (7,000 m)

Time to altitude

12,500 ft (3,800 m) in 10 minutes



2 × forward-firing synchronized 0.300 in (7.62 mm) Marlin Rockwell M1917/M1918 machine-guns.

2 × 0.300 in (7.62 mm) Lewis guns on a Scarff ring in the rear-cockpit plus 1 × Lewis gun firing through an aperture in the aircraft’s belly.

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