Curtiss_Hawk_H-75

Curtiss H-75/P-36 Hawk

The Curtiss H-75 Hawk was an all-metal monoplane Pursuit aircraft with a rotary engine and retractable landing gear operated by the USAAC. Per reference [8] it took its first flight on 6 May 1935. A variant designated the P-36 was procured by the USAAC and entered in 1938. In addition, other variants were procured by numerous air forces around the world, including France, Norway, Portugal, Peru, Brazil, Argentina, the Dutch East Indies, the UK, India, South Africa, China, Persia, Thailand (Siam), Argentina, and Finland (which used ex-French aircraft that had been captured by Germany). In UK and Commonwealth service this aircraft was also called the Mohawk I-IV, depending on variant.

Per reference [8] 215 P-26 aircraft were procured by the US with approximately 900 H-75 export versions also being produced. While the P-36 and some export versions had retractable landing gear, other export versions had fixed gear. The primary three varaints that are included in the aircraft being analyzed at this website include the P-36A which was fitted with an R-1830 engine with a take-off rating of 1050 HP, an H-75A export model fitted with an R-1830/S3C3G engine with a take-off rating of 1100HP, and an H-75A export model fitted with an R-1820 engine with a take-off rating of 1100HP.

As shown in the images below distinguishing features of this aircraft including;

radial engine
a razorback configuration aft the cockpit, with side windows that provide an additional limited degree of view aft for the pilot
a low mounted wing
retractable main landing gear that rotates 90 deg as it retracts into wing

[Image Sources: Public Domain via Ref [8] - as annotated by this site]

[Source: Ref [14a] - US Government/Public Domain]

In order to try and better develop weight estimating relationships an effort has been made to estimate the length of the fuselage aft of the firewall, and the length of the engine section forward of the firewall based off scaled drawings. Together these two distances add to a term called the "structural length" and do not consider any portion of the engine or propeller shaft the extend foward of the fuselage/cowling, or any empennage that extends aft of the fuselage structure. The drawing below shows the current best estimate of these dimensions obtained from available drawings of the airplane and will be updated with any real world data that becomes available. For any aircraft with an inclined firewall, an attempt has been made to locate an approximate center of this location.

P36 Dims

Source Reference [3] [4] & [16]

In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.

The table below summarizes the current data collected on this type aircraft, identifying sources for the data

		Curtiss	Curtiss	Curtiss	Secondary Source	Notes
		P-36A	H-75A (CW)	H-75A (P&W)
Primary Source		3	4	4
No of Crew		1	1	1
Engine:
Qty		1	1	1
Model		R-1830-13	R-1820-G105A	P&W S3C3G	5, 8
Displacement	(cu in)	1830	1820	1830
Power
Military	(HP)			1100	5, 8
War Emergency	(HP)
Normal	(HP)	900	900	950	5, 8
Take Off	(HP)	1050	1100	1100	5, 8
Eng Dims
Length	(ft)	4.94	4.01	5.13	5, 8
Width/Dia	(ft)	4.005	4.59	4.01	5, 8
Height	(ft)
Base Engine Wt	(lb)	1292	1287	1463	5, 8
Propeller
# Blades		3	3	3
Dia	(ft)	10	10.5	10.125
Manufacturer			Curtiss (Elec)	Curtiss (Elec)
Type		Const Speed	Const Speed	Sonst Speed
Wing
Span	(ft)	37.3	37.3	37.3
Root Thickness	(%)	15.0%
	(in)	16.2
Total Area	(sq ft)	236	236	236
Wing (less Ailerons & Flaps)	(sq ft)		182.79	182.79
Ailerons	(sq ft)		18.41	18.41
Flaps	(sq ft)		34.8	34.8
Tail Area	(sq ft)	68.74	68.74	68.74	3
V Tail Area	(sq ft)	20.74	20.74	20.74	3
Fin	(sq ft)		7	7
Rudder	(sq ft)		13.74	13.74
H Tail Area	(sq ft)	48	48	48	3
Stabilizer	(sq ft)		28.8	28.8
Elevator	(sq ft)		19.2	19.2
Total Control Surf Area	(sq ft)		86.15	86.15
Length
Overall	(ft)	28.85	28.8	28.8
Fuselage	(ft)	24.4	26.8	26.8
Body	(ft)	26.8
Body Depth	(ft)
Body Width	(ft)
Fuel Tank Volume	(gal)	163	163	163
Wing Tanks	(gal)	105	105	105
FuselageTanks	(gal)	58	58	58
Oil Tank Volume	(gal)
Water Injection Fluid Tank Volume	(gal)
Wetted Area (sqf)	(sq ft)
Pwr Ldng	(lb/HP)	5.27	5.17	6.38
Wing Ldng	(lb/sq ft)	23.44	24.11	25.08
Struct. Des. GW	(lb)
Ultimate Load Factor	(G's)		12	11.5
Design Speed	(mph)		445	445
Not to Exceed Speed	(mph)	403

Total Struct Weight		1923	2041	2062
Total Wing		814	842	835
Wing
Ailerons
Flaps
Fuselage Carry-Through
Tail		107	112	117
H Tail		74
Stabilizer
Elevator
V Tail		33
Fin
Rudder
Body + Eng Section + LG
Body + LG		1002	1087	1110
Body		470	515	543
Fuselage
Engine Section
Landing Gear		532	572	567
Mn Landing Gr		488
Tail/Nose Aux LG		44
Tail Hook
Booms
Nacelles
Total Propulsion Weight		2004	1985	2170
Engine w/ Accessories		1458
Engine(s) as Installed		1352
Accessories		106
Turbocharger(s)
Controls		7
Propeller(s)		318
2-Blade
3-Blade		318
4-Blade
Starting System		40
Water Injection System
Tanks
Piping Etc
Cooling System
Lube System		27
Tanks
Piping Etc
Fuel System		154
Tanks
Piping Etc
Total Sys. & Eqpmt.		431	457	481
Instruments		59
Surface Controls		90
Hydraulics
Electrical Equip		124
Electronics (Purple means incl in Furn/Gray in Useful Ld)		66
Arm Prov/Equipment & Armor
Furnishings		92
Anti-Ice (If not in Furn)
Other /Misc
Hoisting Gear
Floatation Gear
Armor Plate

Empty Wt		4358	4483	4713
Basic Mission Useful Load		1173	1206	1206
Crew		200	200	200
Equipment
Oil		68	75	75
Fuel		630	630	630
Fuel & Oil Trapped in Systems
Water Solution for Engine Injection
Bombs/Torp Etc
Radio (if Not Included in Empty Wt)			112	112
Nav Equipment
Oxygen System			15	15
Armament		189	174	174
Guns & Ammo		189
Guns		96
Ammo		93			Source References [3] & [16] In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available.In the above images, dimensions in Black come from the source material while dimesions in Red have been approximated from the data available
Pyrotechnics			3	3
Camera
Other
Other Useful Load		86
Basic Mission GW		5531	5689	5919

Notes: This website has been developed with a number of low cost or free programs including Hot Metal Pro, KompoZer, MicroSoft Designer and Da Button Factory.com

Rev 4-12-26

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