Curtiss F11C Goshawk

US Navy Fighter, 27 USN, +3 protos +129 exports

The Curtiss F11C Goshawk is now a somewhat forgotten USN naval biplane fighter of limited production (28 for the BFC-2). Declined into the C2 with landing undercarriage and a sole prototype with Grumman’s retractable undercarriage (C3), it only saw service for a time on USS Saratoga (BFC-2/VB-2B, VF-1B) and Enterprise (VB-6). It had far more success at export as the Hawk I and II for China, Thailand or Colombia and Peru (all seeing action) as well as Chile, Norway, and Turkey.

Development

Curtiss F11c2

1932: XF11 (Model 35B)

In April 1932, Curtiss planned the Model 35B as a private venture to answer potential orders both from the Army Air Corps and U.S. Navy. The latter contracted Curtiss to improve upon the previous Model 34C as well as the F6C. The new model was to be designed the F11C.
-The major change was the choice of a 600 hp (450 kW) Wright R-1510-98 radial engine by the Navy.
-The Navy also precised they wanted a robust single-leg cantilever main landing-gear.
-It was also precised a slight increase in the interplane gap
-A metal (rather than fabric) to cover control surfaces and endure more stresses
-An armament of two .30 in (7.62 mm) fixed forward-firing machine guns
-A hardpoint under the fuselage to carry a 474 lb (215 kg) bomb or auxiliary fuel tank.

Curtiss thus designed the the Model 64 Goshawk (C1). As soon as plans were reviewed and approved by the U.S. Navy designated it the XF11C-1. Later it became XBFC-1 as “BF” for “Bomber-Fighter” was adopted as designation. This new Curtiss model was still of metal construction but fabric-covered. It reused the wing cell structure from the YP-23 back in September 1932.

The Navy then purchased the Model 64A demonstrator (C2) with a Wright R-1820-78 Cyclone engine. It was a slightly longer proposal with a reworked main landing-gear legs and low-pressure tires. There was also a tailwheel replacing the tailskid. The tail was still fabric-covered. There was also an external provision for underwing racks under the wings to carry light bombs but the underbelly hardpoint supported either a 50 gal (189 L) hydrodynamic fuel tank, or a crutch to swing a bomb clear of the propeller disc, if used in a dive-bombing mode.

The XF11C-2 (later XBFC-2) on trials did good, but revealed a number of small changes to be fully accepted. Changes was made and this the XF11C-2 became the production prototype for the F11C-2. 28 were ordered as fighter-bombers in October 1932.

The Curtiss Hawk II or F11C Goshawk represented the end of a long Boeing monopoly on single seat fighters in the US Navy, whereas Curtiss enjoyed a superiority for the USAAC. This model was a return of Curtiss in that branch, but the Navy liked less the larger model compared to the very small Boeing, since space as lacking on its early carriers such as the Langley, Lexington and Saratoga, and now the upcoming USS Ranger. But they believed this sturdy model could work as a fighter bomber, which lacked in its own inventiory, even hoping it to provide dive bombing missions.

1934: The BFC-2, XF-11-3 and BF2C Goshawk

In March 1934, this model was redesigned with a semi-enclosed cockpit plus other modifications and became the BFC-2 to really mark its fighter-bomber nature. The last model of the 28 XF11C-2 contract ordered was then converted to a new prototype called XF11C-3 which incorporated the R-1820-80 engine now had a hand-operated retractable landing gear made by Grumman, relatively unknown at the time.

Curtiss XF11C-3 in Flight

F11C3 Goshawk, train Down

This retractable gear enabled gains in speed, albeit making the new model a bit ungainly and far more tricky to land. Cranking up the train was also seen as a tedious job by the pilot at a time concentration was needed to stabilize the flight after taking off and climb. The BF2C-1 was the follow up of this model, with a raised rear turtle deck, semi-enclosed cockpit, and metal-framed lower wing. It became on the international market the Model 68 Hawk III and is a separate model that will not be seen here but in a next article.

Design of the Curtiss F11C-2 Goshawk

The C-1 and C-2 were pretty close, so we will focus on the second.

General layout

The F11 C1 was an elegant radial engine biplane, single seat, tapered wing sesquiplane, with metal wings, fabric covered, tapered towards the wing tips. The tail surfaces and ailerons were also frame in metal and were metal skinned. The fuselage was a relatively conventional metal tube structure that was metal-skinned, from the cockpit forward while the rear fuselage was fabric covered.

The landing gear consisted of spatted single leg main units and a steerable tail wheel. The F11-C2 switch to wooden wings and tail surfaces, whereas the ailerons were now fabric covered, like the wings. The large wheeltrain was very large, stable and pilots liked it a lot with its fairings, made the model quite recoignisable and “cartoonish”. In fact it was often represented in interwar US cartoons.

Engine and performances

Wright R-1820G
Originally it was equipped with a 600 Hp Wright SR-1500 fourteen cylinder two row radial engine. The Wright SF-1500 of the C-1 was unreliable, and replaced by a 9-cylinder Wright Cyclone SR-1820F engine, enclosed in a NACA cowling. The R-1820 Cyclone was a further development of the Wright P-2 engine from 1925. It had a greater displacement and many improvements, entering production in 1931 and was so simple to maintain and reliable it remained in service well into the 1950s. A legendary model that was also licence-built in France as the Hispano-Suiza 9V or Spain as the Hispano-Wright 9V, Soviet Shvetsov M-25 but also closer to home by Lycoming, Pratt & Whitney Canada, and even Studebaker in WW2.

It was the beating hart of Douglas airliners (DC-1, DC-2, DC-3, DC-5), B-17 Flying Fortress, Douglas SBD Dauntless, Polikarpov I-16 or postwar, the Piasecki H-21 helicopter, it even powered the M6 Heavy Tank. The SR-1820F started as the “SGR-1820-F3” rated for 710 hp (530 kW), 720 hp (540 kW), then the SGR-1820-F2
rated for 720 hp (540 kW), R-1820-F53 rated for 770 hp (570 kW) and finally the R-1820-F56 which developed 790 hp (590 kW).

Armament

If the F11C armament as a fighter was not remarkable with its two forward mounted Browning AN/M2 Browning machine guns, which could be un-jammed by the pilot, it was its ability to carry and deliver a heavy bomb which was appealing to the Navy and justify a small production when Boeing already filled the fighter niche and Grumman was about to make its appearance. The F11C-2 as a regular fighter carried 94 gallons for a Gross weight of 4078 pounds but it coukld carry underbelly an auxiliary tank for a total of 146 gallons (Gross weight 4460 pounds), but also be used as a bomber with the belly 500-pound bomb, with 94 gallons fuel made up to 4596 pounds. It could also carry two 116-pound underwing and in that case ended up at 4326 pounds. It would be even overloaded, carrying its 116-pound bombs AND the auxiliary tank seen above for 146 gallons and 4713 pounds (2.137 kgs). The next BF2C Goshawk also filled that spot of “dive bomber/bomber-fighter” in the USN.

Types

• XF11C-1 (Model 64): First prototype derived from the F6C Hawk.
• XF11C-2 (Model 64A): Second prototype, redesignated XBFC-2.
• F11C-2 (Model 64A): Production version, redesignated BFC-2: 28 built.
• XF11C-3 (Model 67): Since F11C-2 with retractable undercarriage+ 700 hp R-1820-80: XBF2C-1 fighter-bomber.
• XBF2C-1 fighter-bomber: Later designation for the XF11C-3.
• BFC-2 Hawk: Redesignation of F11C-2.
• BF2C-1/Hawk III: Next iteration, produced in numbers.

Operational History

Users

Curtiss F11C-2 from VF-1B in formation

Curtiss Hawk II in Chinese service

Colombian Hawk II F11C

• 9 for the Bolivian Air Force (3 convertible floaptlanes)
• 4 for the Chilean Air Force
• 52 for the Chinese Nationalist Air Force
• 24 for the Colombian Air Force 1932-34, as floatplanes
• 4 Cuban Air Force
• 2 bought for evaluation (by Ernst Udet)
• 1 for the Royal Norwegian Air Force, for evaluation
• 12 for the Royal Thai Air Force
• 24 for the Turkish Air Force (19 August 30, 1932) still active 1940.
• 26 for the Peruvian Navy, second largest operator in the Americas
• 28 for the United States Navy. VF-1B, USS Saratoga.

The model made a relatively long, but limited appearance in the U.S. Navy, with the sole operating unit being the VF-1B “High Hat Squadron” hosted by the ealy fleet carrier USS Saratoga (CV-1), but also VB-6 briefly on USS Enterprise. In March 1934 their designation changed to BFC-2, and so the “High Hat Squadron” beame VB-2B, and late VB-3B, integrating the fighter bomber capacity. BFC-2s remained there in service until… February 1938. VB-6 in fact trained to be deployed on USS Enterprise with the BFC bombers but it never happened, anothger model was chosen instead.

Export: Hawk II

The F11C-2 Goshawk was exported in basically two versions: Hawk I and Hawk II. Both were pure fighters, but only the Hawk II had a belly droppable fuel tank.

-The Hawk I had the Wright R-1820F-3 Cyclone, and 189 liters of internal fuel.
-The Hawk II was a modified XF11C-2 with the same Wright R-1820F-3 Cyclone rated for 710 hp (530 kW) at 1,676 m (5,499 ft) but carrying 356 liters of fuel.
Both had the same armament as the regular F11C-2.

The Hawk II was the only one really exported in quantity. Turkey was the first, after France failed to deliver its awaited LGL-2 fighters in time. After Turkey, Colombia placed an order by late October 1932 (August for Turkey), receiving four with twin float-equipped and more for a total of 26, all float fighters until the end of July 1934. These were deployed on riverine bases inland and saw action in the Colombia-Peru War in 1932-1933. Bolivia was also interested (as Peru and Chile later) and ordered Nine Hawk II, including three with interchangeable wheel/float undercarriages. Chile obtained four. Cuba also obtained four.

Europe also took delivery of more, like Germany which ordered two and Norway a single one for evaluation. The case of Germany is interesting. Ernst Udet, famous WWI veteran pilot (26 April 1896 – 17 November 1941) and second-highest ranking ace, was a known figure in interwar German aviation. He competed a lot, including in the US and even created his own company, Udet Flugzeugbau GmbH dedicated to aerobatics, performing daring manoeuvers on his Flamingo. When witnessing in a US race a Curtiss 1A Hawk piloted by the USN pilot he was impressed and through Gulf Oil sponsoring he acquired it as the unique “Gulfhawk”. Its strenght and diving abilities inspired him to propose the idea to Hitler, which later materialized as the Ju-87 Stuka. He also became a Generaloberst of the Luftwaffe at the time.

In Asia, Thailand obtained 12 Hawk II-IIIs, the latter still active in 1941-42 despite their age. But the most famous and interesting case of course was the Chinese Nationalist Air Force, which received the bulk of the production, no less than 52 F11Cs, sold as “Hawk IIs”. They saw action against the Japanese at the start of the Second Sino-Japanese War in 1937.

Being a good, agile fighter easy to master and popular with pilots, she compensated by raw power a large size and certain lack of agility compared to more nimble Japanese fighters. It soon generated aces. Hawk II squadron commander Captain Chan Kee-Wong of the 28th Squadron for example was part of the 5th Fighter Group based at Chuyung Airbase. His squadron was deployed sometimes 2-3 times daily to intercept Japanese bombers over Nanking, at the outbreak of the war. He co-claimed a Mitsubishi G3M medium-heavy bomber on 15 August 1937.

Half of his squadron was sent to Taiyuan, northern front, and he manage to shoot down Japanese ace, Major Hiroshi Miwa, former military flight instructor for Zhang Xueliang’s Fengtian Army air corps. He was also the commander of the 16th Hiko Rentai as part of 1st Daitai squadron, fyling Kawasaki Ki-10 fighters in the Battle of Taiyuan where most Chinese Hawk II saw action.

Eventually, most operators had it still in inventory as WW2 broke out. The Turkish ones remained on a neutral stance ip to at least late 1942 or 1943 when courted both by the allies and axis, providing modern aircraft. The only belligent that actively used in combat its Hawk II and IIIs in action during World War II was the Royal Thai Air Force, first against the local French Armée de l’Air in 1941, then the British RAF in 1942 and beyond. In fact on 8 April 1944, a Thai Hawk III was shot down by a Bristol Beaufighter over Lamphun. Despite their age, they were kept to the last.

Survivors

Curtiss XBFC-2 Goshawk at the National Naval Aviation Museum
By the spring of 1933, Franz Muller (senior official at the RLM) informed Göring that Udet requested approval for the purchase of two Goshawks for dive bombing trials in the US (see above). Funds were appropriated via the German Embassy in Washington DC. After the 1936 Summer Olympics, one was parked in a field outside Kraków under a tarp, it got forgotten and survived the war. Now it is on display at the Polish Aviation Museum. There is also a BFC-2 is at the National Naval Aviation Museum, NAS Pensacola, Florida and a single Hawk III, restored by the Royal Thai Air Force Museum (in service 1934–1949).

Gallery:

F11C2 Goshawk of VF1B on USS Saratoga, 1937

Royal Thai Hawk II 1936

Ernst Udet personal Hawk II, Olympic Games 1936. He “smuggled” tw disassembled Hawk II on board SS Europa to Germany, arriving in Bremerhaven on October 19 1933. H-80 and H-81 became D-1364 and D-1365 (D-IRIS and D-IRIK). They were reassembled and used for dive bombing tactics. In 1936 he flew one for aerobatic demonstrations over the Olympiastadion.

Turkish Hawk II 1937

Hawk II, 8th Fighter Sqn. CAF Nanking 1937

BFC-2 at the Pensacola Museum

BF2C-1 Goshawk GPN-2000

BFC-2 from VB-3

Curtiss XBF2C-1

Curtiss Model 68, Hawk III ROCAF

Curtiss F11C-2 VF-1B 1-F-16 at NAS San Diego

Curtiss BFC-2 VB-3B

F11 C2

Src/Read more about the FB.5:

Bellomo, Sergio; Cordon Aguirre, Arturo; Marino, Atilio; Núñez Padin, Jorge (1999). Curtiss Hawk. Serie Fuerza Aérea Argentina
Hagedorn, Dan (March–May 1992). “Curtiss Types in Latin America”. Air Enthusiast. No. 45.
Young, Edward M. (1984). “France’s Forgotten Air War”. Air Enthusiast. No. 25.
Ace Captain Chan Kee-Wong and his hawk II
Hawk II/III in the Thai AF
navalaviationmuseum.org
surfcity.kund.dalnet.se
airminded.net
en.wikipedia.org Wright R-1820 Cyclone
brushfirewars.org
wiki Curtiss F11C Goshawk
Curtiss BF2C Goshawk
Curtiss F11C Goshawk
Turkish Hawk II
books.google.fr