The Curtiss P-36 Hawk, also known as the Model 75 or Hawk 75, was a transitional American fighter aircraft that bridged the gap between biplanes and the more advanced monoplanes of WWII.
Though overshadowed by its successor, the P-40 Warhawk, the P-36 saw significant action across multiple theatres—often under foreign flags.
United States
Limited Combat Use
The U.S. Army Air Corps deployed the P-36 primarily in training and secondary roles.
Its most notable combat occurred during the attack on Pearl Harbor (Dec 7, 1941), where a handful of P-36s scrambled from Wheeler Field.
Pilots like 2nd Lt Philip Rasmussen scored early aerial victories despite overwhelming odds.
Obsolescence
By 1941, the P-36 was considered outdated due to its light armament and lack of armour.
It was gradually replaced by the P-40.
France
Major Operator
The Armée de l’Air purchased over 400 Hawk 75s.
During the Battle of France (1940), French pilots flying Hawks claimed 230 confirmed kills and 80 probable’, with only 29 lost in air combat.
Performance
French pilots praised its manoeuvrability and ruggedness, often outperforming early Bf 109s in turning combat.
British Commonwealth
RAF & SAAF Use
Diverted French orders were reallocated to the Royal Air Force and South African Air Force, where the aircraft was known as the Curtiss Mohawk.
Combat Zones
Mohawks saw action in East Africa against Italian forces and in Burma against Japanese aircraft.
Finland
Captured Units
After France’s fall, Germany transferred captured Hawks to Finland, which used them extensively against Soviet forces during the Continuation War.
Effectiveness
Finnish pilots achieved notable success, with the Hawk proving reliable in harsh conditions.
Netherlands & Dutch East Indies
Diversion to Asia
Dutch orders were redirected to the Dutch East Indies, where Hawks engaged Japanese forces during the early Pacific campaigns.
Thailand & Vichy France
Franco-Thai War (1940–41)
Hawks were used by both sides in this brief conflict, marking one of the few instances of the same aircraft type fighting itself.
Model 75A
Company Demonstrator
Engine Fits
Multiple configurations tested, including the Pratt & Whitney R-1830 and Wright R-1820
Function
Curtiss used this aircraft to demonstrate capabilities to foreign buyers, especially during the mid-1930s export push.
Model 75B
Evolution with Wright R-1820 Cyclone
Engine
Wright XR-1820-39 Cyclone, single-row radial
Role
Served as a refined prototype, incorporating aerodynamic and structural improvements over the 75D.
Purpose
Used for USAAC evaluation; helped shape the production-standard P-36 Hawk.
Model 75D
The Original Prototype (1935)
Engine
Wright XR-1670-5 Whirlwind, a two-row radial
Significance
This was the first prototype of the Model 75 series, flown as a private venture by Curtiss to meet the USAAC’s 1935 fighter competition.
Outcome
Though it didn’t win the competition, its innovative design—a low-wing monoplane, retractable gear, and enclosed cockpit—was promising enough to spur further development.
Model 75H
Fixed-Gear Export Simplification
Purpose
A stripped-down version of the Hawk 75, designed for easier maintenance and lower cost.
Landing Gear
Fixed, non-retractable—unusual for a fighter of its era.
Units Built
Two aircraft only.
First
Sold to China, likely for evaluation or limited combat use.
Second
Delivered to Argentina, where it remained in service into the 1950s.
Model 75I
Internal Designation for the P-37
Engine
Inline Allison V-1710, liquid-cooled.
Design Shift
Marked Curtiss’s transition from radial to inline engines.
Outcome
Evolved into the YP-37, which featured a long nose and turbo-supercharging but was ultimately not adopted due to handling issues.
Model 75J
Supercharged Demonstrator
Configuration
A company-owned 75A modified with an external supercharger.
Purpose
Experimental fit to test high-altitude performance.
Result
Not adopted for production; served as a testbed for future engine configurations.
Model 75P
Birth of the P-40 Lineage
Aircraft
P-36A serial 38-010.
Engine
Allison V-1710 inline, liquid-cooled.
Role
Served as the prototype for the Curtiss P-40 Warhawk.
Model 75R
Turbo-Supercharged Speed Trial
Engine
Pratt & Whitney R-1830-SC2-G with turbo-supercharger.
Performance
Reached 330 mph (530 km/h)—impressive for the time.
Model 75E
Y1P-36 Prototype
Designation
Y1P-36 was the USAAC’s evaluation prototype for the P-36 series.
Engine
Pratt & Whitney R-1830 Twin Wasp radial.
Significance
This was the first Curtiss Hawk to feature the R-1830, which became the standard engine for most production P-36s.
Model 75L
P-36A Production Standard
Designation
P-36A was the first production model of the Hawk 75 series adopted by the USAAC.
Engine
Pratt & Whitney R-1830-13 radial.
Armament
One .30 cal and one .50 cal machine gun.
Production
215 units built.
Model 75 (P-42)
Streamlined Experimental Variant
Designation
XP-42, Curtiss’s internal designation, was Model 75 with a modified cowling.
Purpose
Designed to test aerodynamic improvements, especially a long, streamlined nose over the radial engine.
Engine
Pratt & Whitney R-1830-21 with a tight-fitting cowling and spinner.
Performance
Slight speed increase, but cooling issues and minimal gains led to cancellation.
Y1P-36 (Model 75E)
The Y1P-36 was the first Army Air Corps prototype derived from Curtiss’s Model 75B.
It featured a Pratt & Whitney R-1830-13 Twin Wasp engine, retractable landing gear, and enclosed cockpit.
First flown in early 1936, it demonstrated excellent performance and agility, leading to the production contract for the P-36A.
The Y1P-36 set the design foundation for the entire Hawk 75 series and directly influenced the development of the XP-40.
P-36A (Model 75L)
First major production version of the Curtiss Model 75.
Powered by a 900 hp Pratt & Whitney R-1830-13 Twin Wasp radial engine.
Armed with one .30 cal and one .50 cal machine gun in the nose.
210 units were ordered in 1937—the largest U.S. fighter contract since WWI.
Served as the primary USAAC fighter until the arrival of the P-40.
P-36B
Experimental upgrade of the P-36A.
Featured improved armament: two .30 cal and two .50 cal machine guns.
Only one aircraft converted from a P-36A.
Used primarily for testing heavier armament configurations.
P-36C
Final USAAC production variant.
Upgraded engine:
1,200 hp R-1830-17.
Armament increased to one .30 cal. and three .50 cal. machine guns.
30 units built;
Some saw limited combat in the defence of Pearl Harbour.
XP-36F
XP-36D / XP-36E / XP-36F
Experimental conversions of P-36A airframes to test alternative armament layouts.
XP-36D
Two .30 cal. and four .50 cal. machine guns.
XP-36E
Tested wing-mounted armament configurations.
XP-36F
Fitted with 20mm cannon armament; reverted to standard guns after trials
P-36G
Re-designation of Hawk 75A-8 aircraft seized from French orders.
Delivered to the Norwegian training base in Canada.
Retained export configuration with six .30 cal Browning machine guns.
Hawk 75A-1
First French export version (Model 75-Q).
Powered by 1,050 hp R-1830-SC3-G engine.
Armed with four 7.5 mm machine guns (two fuselage, two wing).
100 delivered to France; saw combat during the Battle of France
Hawk 75A-2
Second French batch with improved armament (six 7.5 mm guns).
100 delivered; operated by Groupe de Chasse units.
Notable for scoring early victories against Luftwaffe Bf 109s
Hawk 75A-3
Third French batch; similar to A-2 but with minor equipment changes.
135 delivered; some captured and used by Germany and Finland.
Hawk 75A-4
Final French order before the fall of France.
285 ordered; many diverted to Britain and designated Mohawk IV.
Served in India and East Africa with RAF and SAAF.
Hawk 75A-5
Similar to A-4.
License-built for China; production later moved to India.
Absorbed into RAF as Mohawk IV.
Hawk 75A-6
Norwegian export version.
10 delivered before German invasion;
8 captured and sent to Finland.
Powered by R-1830-SC3-G engine; similar to A-1.
Hawk 75A-7
Dutch East Indies variant.
16 operational during Japanese invasion.
Four modified to carry 50 lbs. bombs.
Hawk 75A-8
Norwegian order of 36 aircraft.
Seized by the U.S. and redesignated P-36G.
Used for training in Canada.
Hawk 75A-9
Iranian order;
never assembled.
Crates discovered in 1941 and repurposed by RAF in the Far East.
Hawk 75M
Chinese variant with fixed landing gear.
Powered by Wright R-1820-G205A.
Armed with four .30 cal MGs.
Hawk 75N
Thai variant with fixed gear and simplified systems.
Used during Japanese invasion of Thailand.
Hawk 75O
Argentine variant with non-retractable landing gear.
30 built by Curtiss,
20 built under license.
Used for training and air defense.
Hawk 75Q
Two demonstration aircraft sent to China.
Used for evaluation and propaganda.
XP-37
Inline-engine derivative of P-36.
Powered by Allison V-1710-11 with turbo-supercharger.
Poor visibility and reliability led to cancellation.
YP-37
Service-test version of XP-37.
13 built.
Continued issues led to abandonment in favor of P-40.
XP-40
Tenth P-36 airframe modified with Allison V-1710.
First flight in 1938.
Led directly to the P-40 Warhawk series.
Specifications
Crew
One
Length
28 ft 6 in (8.69 m)
Wingspan
37 ft 4 in (11.38 m)
Height
8 ft 5 in (2.57 m)
Wing area
235.94 sq ft (21.920 m²)
Airfoil
Root
NACA 2215
Tip
NACA 2209
Empty weight
4,567 lb (2,072 kg)
Gross weight
5,650 lb (2,563 kg)
Max takeoff weight
6,010 lb (2,726 kg)
Powerplant
1 × Pratt & Whitney R-1830-17 Twin Wasp
14-cylinder air-cooled radial piston engine,
1,050 hp (780 kW)
Propellers
3-bladed constant-speed propeller
Performance
Maximum speed
313 mph (504 km/h, 272 kn)
Cruise speed
270 mph (430 km/h, 230 kn)
Range
625 mi (1,006 km, 543 nmi) at 270 mph (230 kn; 430 km/h)
860 mi (750 nmi; 1,380 km) at 200 mph (170 kn; 320 km/h)
Service ceiling
32,700 ft (10,000 m)
Rate of climb
3,400 ft/min (17 m/s)
Wing loading
23.9 lb/sq ft (117 kg/m²)
Power/mass
0.186 hp/lb (0.306 kW/kg)
Armament
Guns
1 × 0.30 in (7.62 mm) M1919 Browning machine gun
1 × 0.50 in (12.70 mm) M2 Browning machine gun
Bombs
Some were later fitted with a hardpoint under each wing that could carry a bomb of up to 100 lb (45 kg)
or
a light bomb rack for three 50 lb (23 kg), five 20 lb (9.1 kg)
or
30 lb (14 kg) bombs.
Sources
I reviewed a selection of publications to gather inspiration for composing the text for this aircraft.
Here’s the list of sources.
Curtiss Aircraft 1907-1947 by Peter M Bowers.
Curtiss Company Profile 1907-1947 by Aeroplane Monthly.
Curtiss Design 75 Hawk, P-36 and International Derivatives by Dan Hagedorn, Amaru Tincopa.
Curtiss P-36 Hawk Cz.1 Monografie Lotnicze 61 by Marek Rys.
Curtiss P-36 Hawk Cz.2 Monografie Lotnicze 62 by Marek Rys.
Curtiss P-36 Hawk Cz.3 Monografie Lotnicze 63 by Marek Rys.
Curtiss Hawk H-75 in French Service MMP Red No.5112 by Lionel Persyn.
Curtiss 75 Hawk Vol 1 Wydawnictwo Militaria by Seweryn Fleischer.
Curtiss Hawk 75 Samolot Mysliwski by Michal M Mietelski.
Curtiss Hawk 75 / P-40M Suomen Ilmavoimien Historia 5 by Kalevi Keskinen, Kari Stenman, Klaus Niska.
Details & Specifications for the Curtiss Hawk 75-A Single-Engine Pursuit Airplane by Curtiss-Wright Corporation.
P-36 Hawk Aces of World War 2 by Lionel Persyn, Kari Stenman, Andrew Thomas, Mark Styling, Mark Postlethwaite.
Polish Wings No.44 Curtiss Hawk 75, H-75, P-36A, Mohawk by Franciszek Strzelczyk, Robert Gretzyngier, Bartlomiej Belcarz, Wojtek Matusiak, Artur Juszczak.
The Curtiss Hawk 75 Profile Publications No.80 by Peter M Bowers.
Curtiss II, III & H75O Hawk Serie Fuerza Aerea Argentina No.5 by Sergio Bellomo, Arturo Cordon Aguirre, Atilio Marino & Jorge F Nunez Padin, Guillermo Landa.
