Curtiss XPW-8B / F6C / P-1 Hawk / P-2 Hawk / AT-4 / AT-5
With its origins in the Model L-18-1 (which stemmed the PW-8 US Army production fighters), the P-1 was a biplane single-engine, single-seat fighter with fixed landing gears. Tapered-wings, wheel brakes and more powerful engines produced a large number of variants for the Curtiss company.
Armed with an array of .303 caliber machine guns, the aircraft had a flight ceiling of over 20,000 feet and speeds in excess of 150 miles per hour.
On 7 March 1925, Curtiss was awarded a contract for 15 production examples of the XPW-8B as the P-1, this being the first fighter to which the company assigned the name Hawk. Externally similar to the XPW-8B, the P-1 was of mixed construction with wooden wings and steel-tube fuselage with fabric skinning, and was powered by a 435hp Curtiss V-1150-1 12-cylinder water-cooled engine. The final five aircraft were completed as P-2s, three of these later being converted to P-1A standards.
They were delivered to the 27th and 94th Pursuit Squad-rons from August 1925, with 435-hp Curtiss V-1150-1 12-cylinder liquid-cooled V-type engines.
Follow-on contracts were placed on 9 September 1925 for 25 P-1As (which had a 7.62cm longer fuselage), revised engine cowling and slightly heavier all-up weight. They were delivered from April 1926, they served with the 17th, 27th and 94th Pursuit Squadrons.
Next production version was the P-1B (again an order for 25, in August 1926), powered by a 435-hp V-1150-3 engine, which had larger main wheels and a modified radiator.
The 33 P-1Cs, ordered in October 1928 and delivered by April 1929, also utilized the V-1150-3 engine and were fitted with wheel brakes.
All these sub-types carried an armament of two 7.62mm guns.
In the meantime, the USAAC had ordered advanced trainers utilising the same airframe. These comprising 35 AT-4s (180hp Wright V-720), five AT-5s and 31 AT-5As (220hp Wright R-790), and, in 1929, these were re-engined with the V-1150-3, all 35 AT-4s becoming P-1Ds and four AT-5s and 24 AT-5As becoming P-1Es and P-1Fs respectively. One other P-1F resulted from reconverting the XP-21, which had previously been a P-3A.
These conversions were essentially similar to the P-1B apart from having only one gun. Four P-1s were supplied to Bolivia, one P-1A went to Japan, and eight P-1As and eight P-1Bs were supplied to Chile.
The P-2s were the last five machines from the original P-1 contract, but powered by 505-hp V-1400 engines; three of these P-2s were converted later to P-1A standard
The Curtiss F6C Hawk series of aircraft was the US Navy/Marine model of the US Army's P-1 Hawk series. The US Navy began fielding the P-1 it as a carrier-based aircraft while the US Marines operated it as a land-based fighter.
In March 1925, the US Navy ordered nine P-1s with provision for float operation as (Curtiss Model 34) F6Cs (the F5C designation was not assigned, to avoid confusion with the F-5 flying boat). Five of these were delivered as F6C-1s with provision for float undercarriage, but no arrester gear, and four (with arrester hooks) as F6C-2s. These had 400-hp Curtiss V-1150 similar power plant to the USAAC's P-1 and the standard two 0.30-in (7.62-mm) gun armament. Two of the F6C-1s were later converted to -2 standard. In 1927, 35 additional aircraft were ordered, these using the P-1A airframe and being designated F6C-3. Two F6C-1s were converted to -3 standard and one F6C-3 was fitted with a Pratt & Whitney R-1340 radial as the XF6C-3.
A batch of 35 incorporating these improve-ments was ordered in 1927; these, plus two others converted from F6C-1s, entered with the USN and USMC in 1928 as the F6C-3. A twin-float F6C-3 won the Curtiss Marine Trophy race in 1930 at a speed of 264.1 km/h (164.1 mph).
Two F6C-2s (the balance of the F6C-1 contract), fitted with arrester hooks and strengthened landing gear, were used for deck trials.
The US Navy had decided, by 1927, to standardise on air-cooled radial engines, which were more easily maintained at sea than liquid-cooled inline engines. After trials with a Pratt & Whitney R-1340- engined F6C-3, a production contract was placed for 31 fighters powered by this 410hp radial as F6C-4s. The first of these aircraft, which was retained for test purposes, was assigned the designation XF6C-4 and deliveries commenced in February 1927. Possessing the same twin-gun armament as its predecessors, the F6C-4 proved more manoeuvrable than the V-1150- powered models, but was becoming obsolescent by the time that it was delivered. The F6C-4 were issued to one squadron only (in the USS Langley) for operational use until 1930; others were put into service as advanced trainers.
A total of 75 of the F6C series Hawks were produced for the US Navy.
Experimental F6C models were:
XF6C-5 (first F6C-1 fitted with a 525hp Pratt & Whitney R-1690 Hornet)
XF6C-6 (an F6C-3 converted to parasol monoplane configuration for the 1930 Thompson Trophy race)
F6C-6 (an F6C-3 modified for 1929 air races and returned to -3 standard)
XF6C-7 (an F6C-4 with an inverted air-cooled Ranger SGV-770 engine).
Engine: 435hp Curtiss V-1150-1 12-cylinder water-cooled
Take-off weight: 1 330 kg
Empty weight: 955 kg / 2105 lb
Wingspan: 9.63 m / 31 ft 7 in
Length: 6.91 m / 22 ft 8 in
Height: 2.72 m / 8 ft 11 in
Wing area: 23.23 sq.m / 250.05 sq ft
Range: 966 km / 600 miles
Maximum speed: 253 km/h (157 mph).
Engine: 505-hp V-1400 engines
Curtiss F6C-3 Hawk
Engine: 1 x Curtiss D.12 Conquerer water-cooled inline, 400hp.
Length: 22.83ft (6.96m)
Wingspan: 31.59ft (9.63m)
Wing area: 23.41 sq.m /251.98 sq ft
Height: 3.25 m / 10 ft 8 in
Maximum Speed: 154mph (248kmh; 134kts)
Maximum Range: 351miles (565km)
Service Ceiling: 20,299ft (6,187m; 3.8miles)
Armament: 2 x .303 inch machine guns
Empty Weight: 2,161lbs (980kg)
Maximum Take-Off Weight: 3,349lbs (1,519kg)
Span: 9.60 m (31 ft 6 in)
Length: 6.86 m (22 ft 6 in)
Gross weight: 1263 kg (2784 lb)
Maximum speed: 249 km/h (155 mph).
Curtiss P-1 Hawk