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The U.S. Army Air Corps had one chance to keep pace with world fighter aircraft development on the eve of World War II, and that chance took the form of the Curtiss P-36 Mohawk
There can be little doubt that the P-36 (or Hawk 75, its Curtiss design designation) placed the USAAC at the forefront of world fighter aircraft design in the late 1930s. But the Hawk 75's potential would never be realized, and the repercussions were far-reaching. The Army's fighters were outclassed when war erupted in September 1939, and there would be years of catch-up before it again could field equipment equal to the world's best.
The purpose of this website is not to rehash the Hawk's development and combat history, which has been documented in publications and other websites, but to offer some new insights into this relatively unknown aircraft. It will attempt to place the Hawk in a new historical context while demonstrating how even limited development might have kept it abreast of world fighter technology.
Some of the ideas presented may be controversial. But over time I hope the site will stimulate the same interest in the Hawk that Dan Ford's Annals of the Brewster Buffalo has done for the F2A.
The Hawk 75 design originated in 1934 around the same time as the Messerschmitt Bf-109, Hawker Hurricane and Supermarine Spitfire. Designed by Donovan R. Berlin, formerly of Northrop, it boasted all-metal monocoque construction, retractable gear and enclosed canopy, design features typical of all later WWII fighters. The design was completed in November, 1934 with the first flight taking place in May 1935. The Hawk was among several contenders to replace the P-26 Peashooter in USAAC service. The evaluation was to take place in May 1935, but the Hawk 75 was the only aircraft to make the deadline. A delivery accident and other problems dogged the Seversky P-35, the Hawk's primary rival, and delayed the competition.
If the flyoff had been held as scheduled the Hawk would have won easily, as the initial P-35 variant was a two-seater with fixed gear. Armed with knowledge of the competition, Seversky used the extra time to modify the P-35 into a single-seater with retractable landing gear, and this redesigned machine won the next competition in August. Curtiss cried foul, demanding more time to refine its design as Seversky had done. A third trial was set for April 1936.
Curtiss used the time make a number of minor changes and to experiment with different engine combinations. Eventually four radial engines were used: the Wright XR-1670-5 twin-row that equipped the prototype, the Pratt & Whitney R1535 twin-row ("Wasp Junior"), the Wright XR-1820-39, (later known as the "Wright Cyclone Nine") and, finally, the P&W R-1830 14-cyl "Twin Wasp".
None of the engines proved entirely satisfactory. Neither the new Cyclone or Twin Wasp developed their promised power, although both later went on to achieve fame in such aircraft as the B-17, B-24, PBY, SBD and Wildcat. The USAAC, however, mandated that both the Hawk and P-35 use the Twin Wasp, , as the Cyclone was experiencing reliability problems.
When the flyoff was finally held in April 1936 neither the P-35 or Hawk 75 could attain the USAAC's required 300 mph benchmark. While both were about equal in performance, Curtiss offered the P-36 at $5,000 less per aircraft. Despite this the USAAC awarded Seversky a contract for 77 aircraft, with Curtiss getting a consolation order for three development aircraft in June 1936 under the designation Y1P-36.
The first Y1P-36 (or Hawk 75E) was delivered to the USAAC test facility at Wright Field in Ohio in June 1937. By this time the Twin Wasp R1830-13 was reliably producing 1,050 HP and the installation to the Hawk 75 airframe was more efficient. These cleaned-up Hawks greatly impressed the USAAC test pilots, and an order for 210 was placed almost immediately.
The first of these were delivered in April 1938. Nearly three years after the prototype first flew, the Hawk 75 was finally flying for the USAAC!
At this point, it might be appropriate to pose the question: how different might events have been if the Hawk 75 had won the initial flyoff in May 1935? If production orders were placed at once, the Hawk might have been in squadron service sometime in 1936 or 1937, at least a year or possibly sooner, before production examples actually showed up on USAAC inventory. The airframe could have been fully de-bugged and ready while development continued on the Cyclone and Twin Wasp. The BF-109 didn't become a first-class weapon until the DB-600 became available, but in the meantime much development work was done on it including combat over Spain. Curtiss made 81 major and minor changes during the initial production run, ranging from structural mods to armament changes, and this could have been done much sooner had the Hawk won the 1935 competition and been placed in production.
But that was not to be. The story of the Hawk 75 is a series of "might haves" and "could haves." Before service deliveries of the Hawk 75 even got underway, Curtiss was already turning its attention toward the P-40. While the pre-production Y1P-36s were being built, Curtiss was converting a prototype 75B model to take the Allison V-1710 liquid-cooled inline engine. Flight tests of this new Hawk, designated XP-37, were already underway by May 1937, and the USAAC ordered 13 as the YP-37. This indicated quite clearly the direction Curtiss was headed.
Let us compare the Hawk 75's developmental timeline with other members of the "Class of 1934." The Bf-109 was conceived in the summer of 1934, first flew in September 1935, and service deliveries (Bf-109B-0) began in the spring of 1937. The Hawker Hurricane was conceived in spring 1934, first flew in October 1935 and service deliveries started at the end of 1937, but would have been later had not Hawker went ahead with productions plans three months before Air Ministry approval. Top speed was supposedly around 312-328 MPH for the prototype and Mark I variants, but it was later revealed that Battle of Britain Hurricanes averaged only 305 MPH. The Spitfire was designed at the end of 1934, appeared in prototype form in March 1936 and service introduction was June 1938.
As delivered to the First Pursuit Group in April 1938, the Hawk 75, now called P-36A in USAAC use, was fitted with 1,050 HP Pratt & Whitney R-1830-13 Twin Wasp Engines. Empty and normal loaded weights were 4567 and 5470 lbs., range was 825 miles, top speed was 300 MPH and climb was 4.8 minutes to 15,000 feet. Armament was one .30 and one .50 caliber machine gun in the cowl upper decking, the USAAC standard at the time.
The P-36 stacked up quite well to the initial models of its fellow Class of 1934 mates. Only the Spitfire clearly outperformed it, being nearly 50 MPH faster and thus able to break off combat at will, and able to outclimb it. But the Hawk was highly maneuverable and retained easy stick and control forces at high speeds, something the Spitfire could not match. It could outdive the Spitfire by a considerable margin , was very rugged (one allegedly set a speed record of 575 MPH in a dive, but I'm unaware of further details) and later proved able to absorb considerable battle damage. Its landing gear, which retracted straight back and rotated 90 degrees to lie flat in the wing, was a Boeing patent used under license by Curtiss. It was far stronger than on any fighter in use at that time. These were hardly the characteristics of an aircraft that was "hopelessly obsolete," as the Hawk 75 is often depicted.
It is said that if an aircraft looks right, it flies right, and even though it was the only member of the Class of 1934 with a radial engine, the Hawk looked every inch a thoroughbred. The fuselage was tall but very narrow, and the P&W R-1830 engine was faired neatly into the fuselage. Only the protruding landing gear knobs on the wing leading edges marred its appearance. It was pointed out in Squadron-Signal's "P-40 In Action" booklet that the P-36 appeared to be "a throughbred race horse" while its successor, the P-40, was "not unlike a dray horse," and the observation is appropriate.
|AIRCRAFT:||Curtiss P-36||Hawk 75A-4||P-40E||Bf109E||Hawker Hurricane||Spitfire||P-35||Zero 21|
|ENGINE:||P&W R-1830||Wright R-1820||Allison V-1710||DM-BENZ DB601||Rolls Royce Merlin II||Rolls Royce Merlin II||P&W R-1830||Sakae 12|
|CLIMB||15K ft/4.8 min||15K/6 min||20K/11.5 min||19.7K/7.45 min||20K/10.3 min||20K/9.4 min||15K/6.9 min||19.7K/7.3 min|
What happened next is well-known. The Spit and Bf-109 would go on to become classic aircraft that served throughout WW II, the Hurricane proved incapable of major performance enhancements and was eventually phased out, and the P-36 was dropped in favor of the Allison-powered P-40 Warhawk series and largely forgotten.
As indicated earlier, work on would become the P-40 series began while Hawk 75 prototypes were being built. Initial test centered around the P-37, an ungainly-looking aircraft with the cockpit placed far aft. The first prototype that really resembled the P-40 appeared in October 1938 when the 10th production P-36A was re-engined with the Allison V-1710-19.
The inline engine did indeed increase the Hawk's top speed. How much is open to some confusion. Speed for the P-40E-K series is often given as 355 to 360 mph, yet the late, lighter P-40N is listed as 343 mph. But if the Allison did increase top speed, it accomplished little else. Installation of the heavier, longer Allison upset the hawk's CG and compromised the Hawk's fine handling, while climb rate also was reduced. Curtiss-Wright's website history page acknowledges the P-40's inferiority to the P-36 in everything but speed.
Later the Warhawk F and L series got the Packard- Merlin V-1650 engine, but
this seems to have done little to advance the Warhawk's combat capabilities,
unlike with the P-51 which saw a huge increase in performance when equipped with
As noted before, the USAAC's engine experimentation concerned the mechanical and turbochargers fitted to a P-36. Both the P-36 and an updated version of the P-35 received the turbocharged R-1830-SC2-G. The resulting Hawk 75R had the turbocharger fitted aft of the cowling and the intercooler underneath the wing trailing edge. It attained 330 MPH at 15,000 feet, apparently the highest speed ever attained by a P-36. The updated P-35 version, redesignated XP-41, did 324 MPH, but the USAAC felt the XP-41 held more potential for development and approved more trials. This machine eventually evolved into the P-43 Lancer and finally morphed into the P-47 Thunderbolt. The 75R was returned to Curtiss' Buffalo plant where it was refitted with a Cyclone R-1820 and used as a demonstrator.The most advanced production version of the Twin Wasp installed was the R-1830-17 engine, which developed 1,200. The -17 engine represented only the very formative stages of R-1830 development. The Hawk 75 never benefited from the later R-1830 versions, including the single-stage, two-speed supercharged R-1830-90, let alone the two-stage, two-speed R-1830-76, which gave the Grumman F4F Wildcat a new lease on life. The presence of this engine allowed the Wildcat to take on the A6M Zero at higher altitudes.
The empty weight of the Army's standard P-36C was 4,620 lbs. empty, 5,734
lbs. loaded. Weight for the folding-wing F4F-4 version were 5,895 lbs. empty and
8,762 lbs. loaded, although the earlier F4F-3 was somewhat lighter. In a Navy
proposal Curtiss estimated a top speed of 351 MPH for a navalized Hawk equipped
with the -76 engine.
Although the USAAC Hawks used the P&W R-1830 as standard, export Hawk 75Ms and Ns used the Wright R-1820 Cyclone Nine as an optional powerplant. Initially, the GR-1820-G3, with only 875 hp., was offered in a simplified Hawk with fixed landing gear. The Hawk 75 A-4, ordered by France, had the 1200 hp R-1820-G205A engine, giving this version a speed of 323 mph at 15,100 ft., the fastest Hawk in operational service. This version, similar to the A-5, A-7, A-8 aand A-9 versions, boasted a climb rate of 2820 fpm.
As with the R-1830, the P-36 never got the advanced versions of the Cyclone.
The R-1820-56W offering 1,350 hp with water injection. The FM-2 Wildcat achieved
322 MPH with this engine, slightly less than the Hawk 75A with the older -G205A
engine. What the Hawk could have done with the -56W engine is sheer speculation,
but, considering the FM-2 loaded weight was still 8,220 lbs, it's reasonable to
assume the Hawk's performance would be superior.
For the Navy fighter trials in May 1938 Curtiss proposed four versions of the Hawk 75, two powered by the twin-row Wright R-2600, which was later to power such aircraft as the Grumman Avenger, B-25, A-20 Havoc and Curtiss Helldiver, and two others powered by versions of the P&W R-1830, including a two-speed, two-stage unit. Curtiss never received authorization to proceed to mockup stage on any of the four proposals. All four of the Curtiss proposals ranked last among the 10 presented. The Vought F4U Corsair won the competition, while a Brewster entry also using the R-2600 was ranked third. Although the Bell Airabonita, a development of the mid-engined USAAC P-39, was ranked sixth, a prototype - the XFL-1 - was ordered.
A memorandum from Capt. S. M. Kraus, who appararently played a large role in evaluating the propsals, to the chief of the Navy Bureau of Aeronautics and dated 28 April 1938, read as follows: "none of the Curtiss single-engine designs is attractive due to the relatively low high speeds, high gross weights and size compared to the other airplanes in the same power category. The 70 mph stalling speed was exceeded in all the Curtiss designs."
Data sheets for the four Curtiss proposals, obtained from the galleries of the National Archives, appear to contradict key elements of Kraus' testimony. Estimated speeds for the four proposals ranged from 366 MPH from a tricycle-geared, mid-wing version of the Hawk, to 321 MPH for the proposal with the single-stage R-1830. According to the data sheets, stalling speed was about 70 MPH for all four of the proposals.
|PROPOSAL:||ENGINE||RANGE||CLIMB||ARMAMENT||GROSS WEIGHT||SPEED||FUEL CAPY|
|PROPOSAL I||Curtiss-Wright R-2600 14 cyl Radial||1000 mls||4.68 Min. @ 15,000 ft.||2x30 cal. MG in fuselage & 2x50 cal MG or 23MM cannon in wings||7881 lbs||360 MPH @ 15K Ft||135 gal.|
|PROPOSAL II||Pratt & Whitney R-1830 single Stage||1013 mls||5.57 Min. @ 15,000 ft||2x30 MG fuselage & 50 cal MG wings||6804 lbs||321 MPH||119 gal.|
|PROPOSAL III||Pratt & Whitney R-1830 two stage||1013 miles||5.7 min. @ 15K ft||2x30 cal MG fuselage & 2x50cal in wings||7,045 lbs||351 MPH||124 gal|
|PROPOSAL IV||Curtiss-Wright @-2600 14 cyl radial||1522 mls||4.65 min @ 15K feet||2x30 cal. MG in fuselage & 2x50 cal. or 2x23MM cannon in wings||7,943 lbs||366 mph||131 gal.|
The following are CorelDraw-enhanced drawings of the proposals obtained from
the Archive files. They're rather rough as my system only supported 8 pixel
graphics, but hopefully they'll convey the general idea.
The Bell XFL-1 Airabonita, a modified version of the P-39 Airacobra, had a top speed of 338 mph, service ceiling of barely 30,000 feet and a climb rate of 2,630 fpm. Although the fastest production P-36, the Hawk 75A-7, only did 323 mph, virtually all of the production Hawks could easily outclimb the XFL-1, even without the later R-1830s and the R2600. The Corsair, although possibly the best overall fighter of WWII, had abominable deck-handling characteristics that kept it off carriers for months. The prototype version of the F6F Hellcat also had the R-2600. In its initial production version, the F6F-3 - even with the larger Pratt&Whitney R-2800 - clocked a relatively modest 376 mph. Moreover, it weighed in at 11,381 lbs. loaded and had a stalling of 72 MPH.
This does not mean the Hawk was a potentially better fighter than the Corsair or F6F. It just suggests the reasons cited by Kraus for ranking the Curtiss proposals dead last seem questionable. While Curtiss' performance figures for the four proposals were estimates only.
It would be interesting to speculate what figures Curtiss would have estimated for USAAC versions with up to 500 more horsepower and higher altitude-rated engines and without the extra weight calculated in for structural modifications, folding wings and arrestor gear.
The French campaign of 1939/40 was the Hawk's most significant combat role. It was second only to the Morane-Saulnier MS406 in numbers and was considered the best fighter in the French inventory with the exception of the Dewoitine D520 which entered service in the closing days of the campaign.
The French initially balked at buying the Hawk, considering it too expensive, but serious problems with the Bloch MB-150 gave them little option. Although the French ordered a almost 300 Hawks armed with the Wright Cyclone (Hawk 75A-4) only six were delivered before the armistice, thus only Twin Wasp models saw combat.
The first delivered were 100 Hawk 75 A-1s with 950 hp R-1830-SC-G, similar to the prototype models for the USAAC. The Hawk 75 A-2, also numbering 100 machines, had R-1830-SC2-Gs offering 1,050 HP and mounted six 7.5 MM Browning machine guns, up from four in the A-1. The Hawk 75 A-3 mounted the PW R-1830-S1C3-G engine, similar to the -17 in the P-36C. Although 135 A-3s were ordered, only 60 reached France before the armistice. The A-4 mounted the 1200 HP R-1820 G205A Wright Cyclone engines, and would have been the most formidable Hawks to serve with the Armee De L' Aire, offering 323 MPH and an initial climb rate of 2820 FPM.
In all, 291 Hawk 75As reached France. Of these, 101 were operational when the Blitzkrieg began in May 1940. The Hawk's primary opponent was the Messerschmitt Bf-109E (see table above), and Hawks scored the first fighter kills in Europe when two Bf-109s were brought down on 8 September 1939. The Hawk was not as well armed as the Bf-109 and much slower, but was more maneuverable at all speeds and could absorb more combat damage.
Four Groupes De Chasse operated the Hawk throughout the campaign, while a fifth replaced its MS-406s with it in early June. The Hawk was the most successful fighter flown by the French during the campaign. Two-Hundered thirty victories were claimed, with GC 1/5 leading with 85 confirmed and 26 probables. There were six aces in this unit alone, with the great Marin La Meslee leading with 20. The elderly MS-406 suffered heavy losses while the MB-152 -an impressive-looking aircraft with its sleek contours and wing-mounted cannon - was the least successful in combat and suffered the heaviest losses.
There has been mixed opinion on the Hawk's performance over France. While some have pointed out that it was flown by elite units, it should also be noted that the majority of Hawks in action over France were the early A-1 and models. Few of the more capable A-3s, and none of the A-4s, were in service. Had the Luftwaffe had to start the war with its initial BF-109B production model, the jagdflieger would have outclassed by the Hawk 75A-1, let alone the later models. In addition the Hawk was older in design and prototype than any of the French types, including even the MS-406 which first flew three months after the Hawk.
In a 1995 interview with World War II magazine, expatriate Czech pilot Frantisek Perina recalled the Hawk's outstanding maneuverability. It could "outmaneuver any German aircraft. If one got on your tail in one 360-degree turn you were behind him." Perina regarded the Hawk as superior to the Hurricane, which he felt was heavier on the controls.
In late 1942 Vichy-operated Hawk 75s fought US Navy Wildcats from the USS Ranger in North Africa. The Vichy Hawks came out on the short end of the stick, losing 15 for the loss of seven Wildcats.
Thanks to the efforts of historians Gerry Beauchanp, Peter Boer, Gerard Casius and others, The Hawk 75's service in the Java - Malaya campaign in early 1942 has been well-documented. The Hawk, however, didn't really have a major impact on the campaign. Only 20 Hawks were obtained by the ML, and most of these were committed to combat piecemeal.
The Dutch Hawks were A-7 models equipped with 1200 hp Wright Cyclone R-1820 G-205 engine, the same as in the Brewster Buffalo. The aircraft reached the Netherlands East Indies during July and August 1940, and some sources indicate the engines were worn out by the time hostilities began nearly a year and a half later. Three of the Hawks were damaged in accidents, leaving 17 available to face the Japanese. The Dutch wanted to buy an additional 28 undelivered French A-4s, but these were given to Britain instead.
Three Hawks were lost during a long-range bombing mission against railroad yards in Thailand 12/17/41. Later in December the Hawks escorted convoy reinforcements to Singapore. By the end of January 1942 12 were left. These were scrambled 3 Feb. 1942 to blunt an attack on Soerabaja, losing three machines destroyed and two others damaged beyond repair. The remainder rose to oppose another assault on 5 Feb., and another Hawk was destroyed and a second damaged. Following these actions the remaining Hawk pilots regrouped as part of a new Hurricane unit. It is believed that three Hawks survived the fighting, and these may have been captured at Andir along with a number of other Allied types, although I have never seen any photos or text to indicate the Japanese evaluated any.
The small number of Hawks committed to the Java campaign, combined with the chaos and confusion of the Japanese advance, makes it difficult to draw many conclusions about its capabilities. Even over Soerabaja the 12 Hawks were divided into three patrols, limiting whatever impact they might have had. Other equipment, including the Buffalo, Hurricane, P-40 and Curtiss-Wright CW-21B Demon - a lightweight, fast-climbing interceptor that might have posed a threat to the Japanese under better circumstances - also fared poorly in the East Indies campaign.
The Hawk is nearly always described as outclassed by the Zero. The Cyclone
Hawk's climb rate was inferior to the Zero 21, as were nearly all fighters of
that era, but speed was almost identical. While the Zero excelled in slow speed
maneuver, the Hawk far surpassed it in high-speed controllability. The reasons
for the Hawk's poor reputation versus the Zero 21 may be due to several
questionable but widely-circulated accounts that told of Hawks falling in droves
before the victorious Japanese. For example, the JAAF's 64th Sentai reported
encountering nine Hawks over Djakarta on 14 Feb. 1942 and shooting down seven,
despite the fact that all Hawks had been destroyed or were unserviceable -- and
the squadron disbanded -- by that date. On Feb. 19, Saburo Sakai's Tainan Air
Wing reported encountering 50 Allied fighters over Soerabaja, with Hawks
supposedly making up a large part of the formation. Sakai personally claimed
three Dutch Hawks during the action. Even allowing for some confusion in dates,
Hawks were never available in sufficient numbers to make these accounts
feasible. Since the Japanese were familiar with Hawks from their combat in
China, it's possible they were more likely to ID Allied aircraft as
and 155 Squadrons
Several South African squadrons received some Cyclone-powered Mohawks in the Middle East, these being among ninety Mohawk IVs (Hawk 75 A-4s) allocated to the Middle East in late 1940. The South African air arm had been fighting the Italians in Ethiopia since mid-1940 and were in desperate need of modern equipment and the Mohawk IVs were the best compromise available. Accordingly in the spring of 1941, sixteen Mohawks were delicvered to East Africa and assembled at Nairobi. Initial operations were hampered by the unrealiability of the Cyclones, and a tech rep from Curtiss Wight was dispatched to try to resolve them.
By September the SAAF No. 3 Squadron was ready to begin operations and problems, and these Hawks were dispatched to Aiscia on the Ethiopian frontier to try ti disrupt Savoia-Marchetti Sm 75 transports. Due to the vast area being patrolled contacts were scarce. A Savoia - apparently in civil registry and Red Cross markings - was destroyed on the ground at Jibouti on 10/05/41 by Capt. Jack Parsonson. This was to be the only aircraft destroyed by Mohawks in Africa, but had the distinction of being the first aircraft destroyed by a Commonwealth-flown Hawk.
While air combat was nonexistent, the SAAF Mohawks were heavilly enaged in ground attack sorties against the Italians at Gondar and throughout Ethiopia. On 12/11/41 Lt.Hugh Gazzard spotted several Vichy French Potez 631s and singled out one for attack. Smoke was emanating from the port engine, but the Potez dived into a cloud before Gazzard could confirm the kill, thus ending the Hawk's only aerial combat in the theater.
Following conclusion of the Ethiopian campaign the Hawks were withdrawn to South Africa where they served as trainers and as defense against Japanese carrier assaults which never materialized.
The Hawk saw more sustained aeriel combat and enjoyed its greatest combat success with the Finnish Air Force, as did the Buffalo. The Finns received both Cyclone and Twin-Wasp powered Mohawks, but I have seen no evidence that Cyclone machines saw operational use. Reports indicate the Finns removed Cyclones from the P-36s to provide spares for the F2A-1 (BW-239) Buffaloes equipping the FAF's elite fighter unit, Hlelv 24.
Hawks arrived too late for the Winter War against the Soviet Union in 1939-40, but were in action for almost all of the "Continuation War" beginning 25 June 1941. The Germans sold them as war booty from the France and Norway and 44 eventually were delivered, with the first arrivals going to recon unit TLeLv 14 to replace Gloster Gladiators and Fokker C Xs and C.VEs. The Hawks were thought to be suited for the recon role due to their fairly long range and 311 MPH speed, which was considered adequate for 1941. In August they replaced Fokker DXXIs in fighter unit HLelV 32, which used them for the remainder of the war.
Although it never achieved the legendary status enjoyed by the Buffalo, the Curtiss was well-regarded by the FAF. It was considered highly maneauverable and rugged, and judged superior to Soviet fighters encountered early in the war, such as the Polikarpov I-153 and I-16. It could hold its own against the faster Lagg 3 due its much-tighter turn radius, but with the arrival of Yaks and La 5s and -7s in 1943 and '44, coupled with more capable Soviet pilots, the elderly Hawks found it more and more difficult to survive. Although the Soviets used lend-lease P-40s over Finland, there is no record of any being claimed by FAF Hawks.
Hawks were credited with 190 kills during the war against eight air combat losses and six due to AA. It boasted the FAF's third-highest victory tally, trailing the BF-109 (663 kills) and Buffalo (477) but edging out the D.XXI (187), a respectable tally considering most of the best FAF "honchos" were selected for the BF-109s and Buffaloes. Its best day was 03/28/42 over Susaari when 12 Hawks encountered 29 Soviets and claimed 17 without loss. The most recent research indicates the top Hawk scorers were Altto Kalevi "Kale" Tervo with 15.75 kills followed by Kyosti Keijo "Kossi" Karhila with 13.25. Lt Jaako Hillo (9) and Capt Paavo Berg (7) were other top guns.
At the close of the Continuation War the 15 survivors were regrouped back
into TLeLv 16 where they had started the war nearly four years earlier. They
managed to soldier on in the FAF as trainers until 1948 when the last (CU-560
and -578) were withdrawn. Unfortunately no Hawks were retained for museum
exhibit by the FAF and I'm aware of no discoveries of salvageable Hawk remains
in the combat zone.
In the fall of 1940 Norway order 24 Hawk 75A-6s with 1200 hp P&W R-1830-S1C3G, but only a few arrived before the nation was overrun by the Wehrmacht. Eight of these went to Finland. Thirty-six more Hawk 75 A-8s with 1200 hp Cyclones were ordered prior to the occupation, and 30 of these were taken over by the USAAF as P-36Gs. All 30 of these eventually went to Peru.
A large number of Hawks served in Chinese Nationalist markings both before and during World War II. All were Cyclone-powered and ranged from the fixed-gear, reduced-power Hawk 75Ms used during the Sino-Japanese conflict, to the higher-performing Hawk 75 A-6s used in 1942.
Up to 112 of the fixed-gear 75Ms were delivered to China beginning in May 1938, which is interesting in that the first production P-36A was delivered to Wright Field in April of that year! While Chinese records account for only 30 Hawks delivered, other accounts say that three full squadrons were operational.
Although the fixed gear and derated Cyclone (875 HP) limited the 75M's speed to just 280 MPH, gross weight was 5305 lbs. versus 5734 for the P-36C, and climb was still respectable. With an armament of four .30 cal. machine guns these so-called "simplified Hawks" should have been the equal of anything in China in 1938, despite the degraded performance. Martin Caidin in his 1967 book "The Ragged, Rugged Warriors" acknowledged it was "in most respects, unquestionably superior" to the Mitsubishi A5M4 (Claude) which had been the scourge of Chinese skies during the fall of 1937.
Unfortunately the poor training and preparedness of both the Chinese pilots and groundcrew eliminated any effectiveness the Hawks might have had. Accidents and mechanical failures destroyed a number of Hawks, while the Japanese strafed and bombed others on the ground. Caidin reported that six of 13 were pranged on a training flight while trying to land. And those that survived had to face the elite Japanese Navy pilots, among the most exhaustively trained in the world.
According to Caidin, the most successful mission flown by a Chinese Hawk occurred during the Japanese bombing of Chungking in 1938. International Squadron pilot George Weigel, who had an extensive stunt flying background but no military flying, shot down four Type 96 Nell bombers on a single mission. It was originally thought this aircraft was an aluminum-finish Hawk 75M modified with a heavy cannon under each wing, but which differed from the standard green-camouflage Chinese 75Ms with machine guns. However the Polish publication Militaria Publications Curtiss 75 book indicates this aircraft was a retractable-gear Hawk 75Q demonstrator which did indeed have the underwing cannons and appeared in overall olive green coloration (top /bottom) in the spring of 1939. It is certain that Weigel flew with the International Squadron, but I have not been able to confirm his tally.
According to the Soviet bomber pilot M. T. Machin a group of French volunteers, supposedly based at Nanchang fought the Japanese with Curtiss Hawks and lost four machines, from which two pilots baled out. After several days, the Japanese shot down three more and one pilot was killed. After this the group ceased to exist. Machin perceived the reason to be the significant superiority of the A5M over the Hawk. It is not clear, though, whether the Hawks in questions were Hawk III biplanes or Hawk 75s.
The Chinese also flew a number of Hawk 75 A-5s in Kunming and other locations
during 1942 and later. Their career apparently was undistinguished, but I hope
to provide more detail later.
Although the Hawk was designed for the USAAC its only combat with that service was at Pearl Harbor on Dec. 7, 1941 when it scored the first US kills of the Pacific war. Thirty-nine Hawks were part of the USAAC defense at Pearl, posted to 78 Sqdn., 18th PG and 46 and 47 Sqdns., 15 PG. Lt. Harry Brown of the 47th PS was one of four Hawk pilots that got into the air and destroyed 2 Nakajima B5N2 Kates of the second wave. Some reports indicate as many as 10 Hawks became airborne, scoring four kills. This action has been detailed in a number of sources.Hawks were posted to 23 Squadron in Alaska, while others served with the 16th and 32nd PGs in the Canal Zone, but saw no combat there.
Peru and Argentina both operated Cyclone-powered Hawks, although none saw
combat use. Peru got 30 P-36Gs (Hawk 75A-8) in 1943 and some of these soldiered
on until the 1960s. Argentina ordered 29 of the "simplified Hawks," designated
Hawk 75Os, in 1938 and later built 20 more under license. These were similar to
the Thai Hawk 75Ns except for a redesigned exhaust system and served as trainers
into the 1960s. For some good pix of the fixed-gear Hawks view this site
The Hawk 75 saw combat with several air forces during WW II, but its use in adequate numbers, and over a sustained period of time, was limited to France, Finland and Burma. The Hawk acquitted itself well in all of these areas despite the fact it never progressed beyond the earliest stages of development. If the Hawk had been battling its true Axis contemporaries, its opponents would have been the Nakajima Ki-27 Nate, the Mitsubishi A5M4 Claude and the Jumo-engined Messerschmitt Bf-109 B, C and D.
The only mid-thirties fighter clearly superior to the Hawk was the Spitfire. But even against this superlative design the Hawk handled better at high speeds, and its structure and landing gear -- the same used on such weightlifters as the Corsair, Hellcat and Skyraider - would have permitted much higher gross weights.
The Hawk had excellent control and handling, qualities pointed out by everyone who flew it. Its climb rate was competitive despite the low horsepower engines installed. By any yardstick, the Hawk was a great platform for further development. Had it received later versions of the Cyclone and Twin-Wasp, or perhaps the R-2600 - which eventually put out 1,900 hp - it could perhaps have remained competitive until the close of the war. As it was the only real "development" done on the Hawk was to simplify it for peddling to second-tier air arms.
What happened? I believe the critical lapse was the failure to award the USAAC fighter contract to the Hawk in May 1935. Had it won that competition as it should have, the Hawk could have been in service use by the summer of 1936. The USAAC and Curtiss would have had ample time to wring out the bugs and develop its potential. But production was not ordered until July 1937, and the first production Hawks didn't reach the Air Corps until April, 1938. By then it was too late. The Hawk was already falling behind foreign designs, and the Air Corps took what seemed to be a logical step by adopting the Allison-engined P-40. This move got the Hawk "up to speed" but handling and climb both suffered and the P-40 could not keep pace with foreign designs. In addition, preoccupation with the P-40 blinded the USAAC to the potential of the P-36.
Two more Hawk survivors have materialized since this site was created in 2002. The Fighter Collection of the UK features a French survivor restored in the US and flown earlier in 2004. The machine was recovered from a French collector in the 1980s and had been in storage for many years. A Finnish survivor is also said to be under restoration in New Zealand. It allegedly was recovered from Russia several years ago and when found was displaying the German markings in which it was delivered to Finland.>/P>
Although the p-36 Hawk is rather obscure as fighter planes go, it's fared well as a plastic model subject. I hope to complete these kits and post pictures to this site as time permits.
AZUR and AML, from the Czech Republic, released excellent renditions of the
Cyclone-powered Hawk 75 A-4 in the late '90S. AML also used the A-4 as a basis
for P&W Hawk 75 A-1 thru A-3 versions. Although lacking the resin detail
of these Czech kits, the classic Monogram Hawk kit is still well worth building.
As this site was being revised Azur was set to release a 1/32 P-36 Pratt & Whitney Mohawk in Pearl Harbor markings (November 2005). This is a "done deal" and will unquestionably be the ultimate Hawk 75 in plastic if Azur's earlier 1/32 releases are any indication. The price should be quite reasonable as well. It is not known whether Azur will offer a Cyclone version.
© Bruce Crawford @ 2002