The P-1 Hawk (Curtiss Model 34) was a 1920s open-cockpit biplane fighter aircraft of the United States Army Air Corps.

Although the PW-8 was faster than the PW-9 (both having top speeds in excess of 165 mph), it was otherwise outperformed by the Boeing plane, and its surface radiator cooling system, mounted on the upper and lower surfaces of the top wing for streamlining, was more difficult to maintain and vulnerable in combat.

The first production P-1, serial number 25-410, was delivered on August 17, 1925, and was followed in successive years by the P-1B and P-1C variants with improved engines.

The March 7, 1925 order for the P-1 also requested five aircraft with the more powerful 500 hp (373 kW) Curtiss V-1400 engine installed.

The first (SN 25-420) was then modified with a turbocharger mounted on the right side of the fuselage nose, and whose turbine was driven by engine exhaust; the craft was designated XP-2.

[4] The remaining four aircraft were production P-3As, but primarily used to service test the Pratt & Whitney Wasp engine.

Addition of a Townend ring cowling worsened the visibility problem, and had only a limited effect on speed.

[8] On June 23, 1924, taking off at 3:58 A.M., Army test pilot First Lieutenant Russell Maughan left Mitchel Field, New York, in PW-8 24-204, modified with additional fuel and oil tanks, made a dawn-to-dusk transcontinental flight across the US.

His flight time included four planned 30-minute stops at McCook Field, Ohio; Saint Joseph, Missouri; Cheyenne, Wyoming; and Salduro Siding, Utah; and an unplanned stop in North Platte, Nebraska for additional fuel when a muddy field in Missouri did not permit him to take on a full load.