P-1 Hawk
Encyclopedia
The P-1 Hawk (Curtiss Model 34) was a 1920s open-cockpit
biplane
fighter aircraft
of the United States Army Air Corps
. An earlier variant of the same aircraft had been designated PW-8 prior to 1925.
P-1 Hawk was the first US Army Air Service aircraft to be assigned the "P" (Pursuit) designation which replaced seven designations for pursuit aircraft, including "PW" (for "Pursuit, Water-cooled engine"). The P-1 was the production version of the Curtiss XPW-8B, an improved variant of the PW-8, 25 of which were operational with the Air Service's 17th Pursuit Squadron
In September 1923, the Army ordered production of the PW-8. The PW-8 (Curtiss Model 33) had been developed from the R-6 racer
and was acquired by the Air Service after a competition with the Boeing Model 15
, designated the PW-9, to replace the existing Army fighter, the Boeing MB-3A. Although the PW-8 was faster than the PW-9 (both having top speeds in excess of 165 mph), it was otherwise out-performed by the Boeing plane, and its cooling system appeared to be more difficult to maintain and vulnerable in combat. However Assistant Chief of the Air Service Brig. Gen. Billy Mitchell agreed to purchase 25 PW-8s in return for assistance by Curtiss in making the Dawn-to-dusk transcontinental flight across the United States.
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. These were completed in January 1926. The first (SN 25-420) was then modified with a supercharger
mounted on the right side of the fuselage
nose, and whose turbine was driven by engine exhaust; the craft was designated XP-2.
However, the Curtiss V-1400 engine did not perform up to expectations, with or without the supercharger, and so after a year in service, three of the standard P-2 Hawks had their engines replaced with the Curtiss V-1150 and were consequently redesignated as P-1s. The fifth machine (25-243) received a Curtiss V-1570 Conqueror engine and became the XP-6.
93 production P-1s were brought into service in the P-1, P-1A, P-1B, and P-1C variants. 52 other P-1s, variants P-1D, P-1E, and P-1F, were made by conversion of other Hawk variants, primarily AT-4 and AT-5 trainers.
radial engine
. The first of the type, designated XP-3A, was the last P-1A (serial 26-300). Originally intended to be powered by a 390 hp (291 kW) Curtiss R-1454, the engine was deemed unsatisfactory and the 410 hp (306 kW) Pratt & Whitney R-1340 engine substituted. A second XP-3A (serial 28-189) included a cowling
and spinner
to reduce the drag due to the radial engine; entered in the National Air Races
of 1929, its speed of 186.84 mph (300.69 km/h) gave it second place in the Thompson trophy
race.
The remaining four craft were production P-3As, but primarily used to service test the Pratt & Whitney Wasp
engine. In addition to the significant increase in drag, the radial engine also interfered with the pilot's view. Addition of a Townend ring
cowling worsened the visibility problem, and had only a limited effect on speed. It was also tested with various types of deep-chord NACA cowls.
Two of the XP-3A aircraft were re-engined in 1929 and 1930 with the Pratt & Whitney R-985-1 Wasp Junior
engine. This aircraft was re-designated the XP-21. Tests were run with this aircraft, but it was never developed into a production aircraft, despite the designation.
Five P-5 Superhawks, similar to the P-1C but with a turbocharged V-1150-3 engine, were delivered in 1928. They had a top speed of 166 mph (267 km/h) at 25,000 ft (7,620 m), considerably higher than the maximum ceiling of the P-1A, but their low-level performance was inferior
A total of 202 PW-8, P-1, P-2, P-3, P-4, P-5, AT-4, and AT-5 airplanes were delivered.
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. Refueling five times, he landed at Crissy Field
, San Francisco, California, at 9:46 p.m., one minute before dusk, covering 2,670 mi (4,297 km) in 20 hours and 48 minutes. 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. He also lost an hour at McCook to repair a broken fuel valve after an over-eager mechanic had over-torqued the valve, damaging it.
The original fifteen P-1s served in the 27th and 94th Pursuit Squadrons, 1st Pursuit Group
, Selfridge Field
, Michigan
. The first Hawk to serve with the Air Corps in quantity was the P-1A (17th, 27th, and 94th Pursuit Squadrons) beginning in 1925. In October 1928 the largest order of 33 P-1s was made. These were delivered by April 1929 as P-1Cs.
The AT-4 and AT-5 trainer variants served with the 43rd Pursuit Squadron (School) at Kelly Field, Texas.
XPW-8
PW-8
XPW-8A
XPW-8B
P-1
P-1A
XP-1A
P-1B
P-1C
XP-1C
P-1D
P-1E
P-1F
P-2
XP-3
XP-3A
XP-21
P-3A
XP-4
XP-5
P-5
XAT-4
AT-4
AT-5
AT-5A
CO-X
All variants increased in weight with each succeeding model, resulting in slight reductions in performance with each.
A variant designated Hawk 3 or Hawk III, tail number and specifications unknown, has been restored by the Royal Thai Air Force Museum
.
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
biplane
Biplane
A biplane is a fixed-wing aircraft with two superimposed main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...
fighter aircraft
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
of the United States Army Air Corps
United States Army Air Corps
The United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...
. An earlier variant of the same aircraft had been designated PW-8 prior to 1925.
PW-8
The CurtissCurtiss Aeroplane and Motor Company
Curtiss Aeroplane and Motor Company was an American aircraft manufacturer that went public in 1916 with Glenn Hammond Curtiss as president. Throughout the 1920s and 1930s, the company was the largest aircraft manufacturer in the United States...
P-1 Hawk was the first US Army Air Service aircraft to be assigned the "P" (Pursuit) designation which replaced seven designations for pursuit aircraft, including "PW" (for "Pursuit, Water-cooled engine"). The P-1 was the production version of the Curtiss XPW-8B, an improved variant of the PW-8, 25 of which were operational with the Air Service's 17th Pursuit Squadron
In September 1923, the Army ordered production of the PW-8. The PW-8 (Curtiss Model 33) had been developed from the R-6 racer
Curtiss CR
|-See also:-External links:* *...
and was acquired by the Air Service after a competition with the Boeing Model 15
Boeing Model 15
-Bibliography:*Lloyd S. Jones, U.S. Naval Fighters Fallbrook CA: Aero Publishers, 1977, pp. 35-38. ISBN 0-8168-9254-7.*Swanborough, Gordon and Bowers, Peter M. United States Navy Aircraft since 1911. London: Putnam. Second edition 1976. ISBN 0-370-10054-9....
, designated the PW-9, to replace the existing Army fighter, the Boeing MB-3A. Although the PW-8 was faster than the PW-9 (both having top speeds in excess of 165 mph), it was otherwise out-performed by the Boeing plane, and its cooling system appeared to be more difficult to maintain and vulnerable in combat. However Assistant Chief of the Air Service Brig. Gen. Billy Mitchell agreed to purchase 25 PW-8s in return for assistance by Curtiss in making the Dawn-to-dusk transcontinental flight across the United States.
P-1
The prototype of the P-1, the XPW-8B, came about when the Air Service, which had selected the Boeing PW-9 over the PW-8 as its main production fighter, asked Curtiss to modify the last of its three original XPW-8 prototypes with wings resembling those of the PW-9. Curtiss designated the modified aircraft its Model 34A and returned it to the Air Service for evaluation, from which the service ordered it into production as the P-1. 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 newest P-1 variants remained in operational service until 1930.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
Inline engine (aviation)
In aviation, an inline engine means any reciprocating engine with banks rather than rows of cylinders, including straight engines, flat engines, V engines and H engines, but excluding radial engines and rotary engines....
installed. These were completed in January 1926. The first (SN 25-420) was then modified with a supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
mounted on the right side of the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
nose, and whose turbine was driven by engine exhaust; the craft was designated XP-2.
However, the Curtiss V-1400 engine did not perform up to expectations, with or without the supercharger, and so after a year in service, three of the standard P-2 Hawks had their engines replaced with the Curtiss V-1150 and were consequently redesignated as P-1s. The fifth machine (25-243) received a Curtiss V-1570 Conqueror engine and became the XP-6.
93 production P-1s were brought into service in the P-1, P-1A, P-1B, and P-1C variants. 52 other P-1s, variants P-1D, P-1E, and P-1F, were made by conversion of other Hawk variants, primarily AT-4 and AT-5 trainers.
P-3 and P-5 test variants
The P-3 Hawk was similar to the P-1 Hawk but with a radial R-1340-3 WaspPratt & Whitney R-1340
|-See also:* Pratt & Whitney Wasp series* Pratt & Whitney R-985 Wasp Junior* Pratt & Whitney R-1535 Twin Wasp Junior* Pratt & Whitney R-1830 Twin Wasp-Bibliography:...
radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
. The first of the type, designated XP-3A, was the last P-1A (serial 26-300). Originally intended to be powered by a 390 hp (291 kW) Curtiss R-1454, the engine was deemed unsatisfactory and the 410 hp (306 kW) Pratt & Whitney R-1340 engine substituted. A second XP-3A (serial 28-189) included a cowling
Cowling
A cowling is the covering of a vehicle's engine, most often found on automobiles and aircraft.A cowling may be used:* for drag reduction* for engine cooling by directing airflow* as an air intake for jet engines* for decorative purposes...
and spinner
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
to reduce the drag due to the radial engine; entered in the National Air Races
National Air Races
The National Air Races were a series of pylon and cross-country races that took place in the United States from 1920 to 1949. The science of aviation, and the speed and reliability of aircraft and engines grew rapidly during this period; the National Air Races were both a proving ground and...
of 1929, its speed of 186.84 mph (300.69 km/h) gave it second place in the Thompson trophy
Thompson trophy
The Thompson Trophy race was one of the National Air Races of the heyday of early airplane racing in the 1930s. Established in 1929, the last race was held in 1961. The race was long with pylons marking the turns, and emphasized low altitude flying and maneuverability at high speeds...
race.
The remaining four craft were production P-3As, but primarily used to service test the Pratt & Whitney Wasp
Pratt & Whitney Wasp
-External links:*...
engine. In addition to the significant increase in drag, the radial engine also interfered with the pilot's view. Addition of a Townend ring
Townend ring
A Townend Ring is a narrow-chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling.-Development:...
cowling worsened the visibility problem, and had only a limited effect on speed. It was also tested with various types of deep-chord NACA cowls.
Two of the XP-3A aircraft were re-engined in 1929 and 1930 with the Pratt & Whitney R-985-1 Wasp Junior
Pratt & Whitney R-985
The Pratt & Whitney R-985 Wasp Junior is a series of nine-cylinder air-cooled radial aircraft engines built by the Pratt & Whitney Aircraft Company from the 1930s to the 1950s. These engines have a displacement of ; initial versions produced , while the most widely used versions produce...
engine. This aircraft was re-designated the XP-21. Tests were run with this aircraft, but it was never developed into a production aircraft, despite the designation.
Five P-5 Superhawks, similar to the P-1C but with a turbocharged V-1150-3 engine, were delivered in 1928. They had a top speed of 166 mph (267 km/h) at 25,000 ft (7,620 m), considerably higher than the maximum ceiling of the P-1A, but their low-level performance was inferior
AT-4 and AT-5 trainers
Two single-seat advanced trainer variants were placed into production, the AT-4 and AT-5A, using Wright-Hispano engines. All were re-engined with Curtiss D-12D engines and reverted to use as fighters, designated P-1D and P-1F respectively. Five AT-4/XAT-5 test variants were re-classified as P-1E.A total of 202 PW-8, P-1, P-2, P-3, P-4, P-5, AT-4, and AT-5 airplanes were delivered.
Operational history
On June 23, 1924, taking off at 3:58 A.M., Army test pilotTest pilot
A test pilot is an aviator who flies new and modified aircraft in specific maneuvers, known as flight test techniques or FTTs, allowing the results to be measured and the design to be evaluated....
First Lieutenant
First Lieutenant
First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...
Russell Maughan
Russell Maughan
Russell Lowell Maughan was a pioneer aviator and U.S. military pilot. His career spanned a period in which the Air Force, then part of the U.S. Army, was known as the Aviation Section, U.S. Signal Corps; U.S. Air Service; U.S. Army Air Corps; and U.S. Army Air Forces. Maughan was born March 28,...
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. Refueling five times, he landed at Crissy Field
Crissy Field
Crissy Field is a former airfield, now a part of the Golden Gate National Parks Conservancy in San Francisco, California, United States. Historically a part of the Presidio of San Francisco, Crissy Field was closed as an airfield and eventually the National Park Service took control over it...
, San Francisco, California, at 9:46 p.m., one minute before dusk, covering 2,670 mi (4,297 km) in 20 hours and 48 minutes. His flight time included four planned 30-minute stops at McCook Field
McCook Field
McCook Field was an airfield and aviation experimentation station operated by the Aviation Section, U.S. Signal Corps and its successor the United States Army Air Service from 1917-1927...
, Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
; Saint Joseph, Missouri
Saint Joseph, Missouri
Saint Joseph is the second largest city in northwest Missouri, only second to Kansas City in size, serving as the county seat for Buchanan County. As of the 2010 census, Saint Joseph had a total population of 76,780, making it the eighth largest city in the state. The St...
; Cheyenne, Wyoming
Cheyenne, Wyoming
Cheyenne is the capital and most populous city of the U.S. state of Wyoming and the county seat of Laramie County. It is the principal city of the Cheyenne, Wyoming, Metropolitan Statistical Area which encompasses all of Laramie County. The population is 59,466 at the 2010 census. Cheyenne is the...
; and Salduro Siding, Utah
Wendover, Utah
Wendover is a city in Tooele County, Utah, United States. It is part of the Elko Micropolitan Statistical Area. The population was 1,537 at the 2000 census, with a 2006 estimated population of 1,632....
; and an unplanned stop in North Platte, Nebraska
North Platte, Nebraska
North Platte is a city in and the county seat of Lincoln County, Nebraska, United States. It is located in the southwestern part of the state, along Interstate 80, at the confluence of the North and South Platte Rivers forming the Platte River...
for additional fuel when a muddy field in Missouri did not permit him to take on a full load. He also lost an hour at McCook to repair a broken fuel valve after an over-eager mechanic had over-torqued the valve, damaging it.
The original fifteen P-1s served in the 27th and 94th Pursuit Squadrons, 1st Pursuit Group
1st Operations Group
The 1st Operations Group is the flying component of the 1st Fighter Wing, assigned to the USAF Air Combat Command. The group is stationed at Langley Air Force Base, Virginia. The 1st Operations Group is the oldest major air combat unit in the United States Air Force, being a successor organization...
, Selfridge Field
Selfridge Field
Selfridge Air National Guard Base or Selfridge ANGB is an Air National Guard installation located in Harrison Township, Michigan, near Mount Clemens.-Units and organizations:...
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. The first Hawk to serve with the Air Corps in quantity was the P-1A (17th, 27th, and 94th Pursuit Squadrons) beginning in 1925. In October 1928 the largest order of 33 P-1s was made. These were delivered by April 1929 as P-1Cs.
The AT-4 and AT-5 trainer variants served with the 43rd Pursuit Squadron (School) at Kelly Field, Texas.
Variants
While a total of 202 Hawks were built in the basic variants PW-8, P-1, P-2, P-3, P-5, AT-4 and AT-5, conversions resulted in 148 having a P-1 designation.XPW-8
- 3 manufactured, one modified to XPW-8A and later XPW-8B standard, one converted to CO-X two-seat observation aircraft.
PW-8
- 25 produced and flown by 17th Pursuit Squadron
XPW-8A
- An XPW-8 converted with a new cooling system and modified wings for trials
XPW-8B
- Model 34 - The XPW-8A fitted with single-bay tapered wing as prototype for the P-1 series.
P-1
- Model 34A - Production version of the XPW-8B with modified rudder and additional wing center strut, and Clark Y aerofoil, powered by 435 hp (324 kW) Curtis V-1150-1Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
(D12), 10 built.
P-1A
- Model 34G - P-1 with 3-inch fuselage stretch, larger wheels and revised fuel system, 25 built with D-12CCurtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
engine and three conversions from P-2. Final two converted to XAT-4 Trainer and XP-3 racer prototypes. Delivered in 1926.
XP-1A
- One P-1A used for development trials.
P-1B
- Model 34I - 25 produced with Curtis V-1150-3Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
(D-12D) engine. Increased weight reduced performance. Delivered 1927.
P-1C
- Model 34O - 33 built with Curtis V-1150-5Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
(D-12E) engine. Increased weight further decreased performance. delivered 1927-28.
XP-1C
- One P-1C fitted with a revised radiator.
P-1D
- 24 conversions from AT-4 trainers, re-engined with Curtis V-1150-3Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
(D-12D) engines.
P-1E
- 4 conversion from AT-5 trainers re-engined with 440 hp (328 kW) V-1150-3 built as AT-4s and converted to XAT-5 prototype. All re-engined and converted to P-1E.
P-1F
- 24 conversions from AT-5A trainers, one conversion from XP-21A, all re-engined with a 440 hp (328 kW) Curtis V-1150-3Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
in 1929.
P-2
- Model 34B - P-1 with a 500 hp (373 kW) Curtiss V-1400, five built.
- 3 later converted to P-1A and one re-engined with the Curtiss V-1570-1Curtiss V-1570|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9-External links:...
as the XP-6.
- 3 later converted to P-1A and one re-engined with the Curtiss V-1570-1
XP-3
- Radial-engined version, one converted from a P-1A with 390 hp (291 kW) Curtiss R-1454 engine, later converted to XP-3A.
XP-3A
- XP-3 re-engined with a 410 hp (306 kW) Pratt & Whitney R-1340-1
XP-21
- XP-3A re-engined with the Pratt & Whitney R-985 Wasp JuniorPratt & Whitney R-985The Pratt & Whitney R-985 Wasp Junior is a series of nine-cylinder air-cooled radial aircraft engines built by the Pratt & Whitney Aircraft Company from the 1930s to the 1950s. These engines have a displacement of ; initial versions produced , while the most widely used versions produce...
.
P-3A
- Model 34N - five production aircraft to the AT-5A design with a 410 hp (306 kW) Pratt & Whitney R-1340-7.
XP-4
- P-1A modified with a supercharged 510 hp (380 kW) Packard 1A-1530 engine.
XP-5
- P-1A version with a 435 hp (324 kW) Curtiss V-1150-3Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
engine.
P-5
- Model 34L - four built, same as XP-5 later modified with the Curtiss D-12Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
F engine.
XAT-4
- Model 34J - P-1A re-engined with a 180 hp (134 kW) Wright-Hispano E as an advanced trainer.
AT-4
- Production version of the XAT-4, 40 ordered, first 35 were converted in 1929 to P-1Ds with the Curtiss D-12Curtiss D-12|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.-External links:*...
engine, and the remainder completed as AT-5s.
AT-5
- Model 34J - five aircraft originally to AT-4s re-engined with a 220 hp (164 kW) Wright J-5, later converted to P-1Es.
AT-5A
- Model 34M - 31 aircraft based on the P-1B with a lengthened fuselage, later converted to P-1Fs.
CO-X
- the first XPW-8 prototype was converted into a two-seat observation aircraft.
All variants increased in weight with each succeeding model, resulting in slight reductions in performance with each.
A variant designated Hawk 3 or Hawk III, tail number and specifications unknown, has been restored by the Royal Thai Air Force Museum
Royal Thai Air Force Museum
-Overview:The Royal Thai Air Force Museum is located in Bangkok, Thailand. It is located on the Phanonyothin road just to the south of Wing 6 of the domestic terminal of the Don Muang Airport. The museum is open daily from 8am to 4pm....
.
Operators
- Four P-1s were supplied to Bolivia.
- Eight P-1As and eight P-1Bs went to Chile.
- One P-1A went to Japan.
- Designated Hawk III or Hawk 3, served in the Royal Thai Air ForceRoyal Thai Air ForceThe Royal Thai Air Force or RTAF is the air force of the Kingdom of Thailand. Since its establishment in 1913, as one of the earliest air forces of Asia, the Royal Thai Air Force had engaged in many major and minor battles. During the Vietnam war era, the air force has been developed with USAF-aid...
between 1934 and 1949.
- United States Army Air CorpsUnited States Army Air CorpsThe United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...