Curtiss_P-40.htm

Curtiss P-40 Warhawk

The Curtiss P-40 Warhawk was an all-metal monoplane Pursuit aircraft with an inline engine and retractable landing gear operated by the USAAC. It was derived from the Curtiss H-75/P-36 by replacing the R-1830 Pratt & Whitney radial engine with an inline Allison V-1710 engine. Per reference [8] it took its first flight on 14 October 1938, and entered operational service in 1939. The P-40 was built in many variants, most fitted with an Allison V-1710 engine, but some variants were fitted with a V-1650 Packard Merlin engine. The primary variants analyzed at this website include:

the Allison engined P-40E
the Merlin engined P-40F
the Allison engined P-40K
the Merlin engined P-40L
the Allison engined P-40M
the Allsion engined P-40N-25

In addition to the USAAC variants were procured by numerous air forces around the world including the UK, Canada, Australia, New Zealand, South Africa, the Dutch East Indies, Indonesia, China, Poland, France, Egypt, Turkey, the Soviet Union, and Brazil. In UK and Commonwealth service this aircraft was also called the Tomahawk I-II or the Kittyhawk I, IA, II, IIA, III, or IV, depending on variant. Per reference [8] a total of 13,738 P-40 aircraft of all variants were procured.

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

an inline engine
a chin mounted radiator and oil cooler air inlet
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

In the P-40N variant, although it had a similar profile as the other variants, the structure immediately aft of the cockpit behind the pilot's head was modified in an attempt to improve visibility aft for the pilot.

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

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

P-40X_3-view

[Source: Ref [8] - 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.

P40 Short

Source References [1] [2] & [16]
(Short Tailed P-40E & P-40K are believed to have similar dimensions)

P-40 Long

Source References [1] & [16]
(Long Tailed P-40K & P-40M are believed to have similar dimensions)

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


		Curtiss	Curtiss	Curtiss	Curtiss	Curtiss	Curtiss	Curtiss	Secondary Source	Notes
		P-40E	P-40E	P-40F	P-40K	P-40L	P-40M	P-40N-25
Primary Source		1	2	1	1	1	1	1
No of Crew		1	1	1	1	1	1	1
Engine:
Qty		1	1	1	1	1	1	1
Model		V-1710-39	V-1710-39	V-1650-1	V-1710-73 (F4R)	V-1650-1	V-1710-81	V-1710-99	5
Displacement	(cu in)	1710	1710	1650	1710	1650	1710	1710	5
Power
Military	(HP)	1150	1150	1240	1150			1125	5
War Emergency	(HP)	1490	1490		1580	1435		1360	5
Normal	(HP)
Take Off	(HP)	1150	1150	1390	1325	1385	1360	1200	5
Eng Dims
Length	(ft)
Width/Dia	(ft)
Height	(ft)
Base Engine Wt	(lb)	1310	1310		1345	1510		1355	5
Propeller
# Blades		3	3	3	3	3	3	3
Dia	(ft)	11	11	11	11	11	11	11
Manufacturer		Curtiss (Elec)	Curtiss (Elec)	Curtiss (Elec)	Curtiss (Elec)	Curtiss (Elec)	Curtiss (Elec)	Curtiss (Elec)
Type		Const Speed	Const Speed	Const Speed	Const Speed	Const Speed	Const Speed	Const Speed
Wing
Span	(ft)	37.3	37.3	37.3	37.3		37.3	37.3
Root Thickness	(%)	15.0%	15.0%
	(in)	16.2	16.2
Total Area	(sq ft)	236	236	236	236	236	236	236
Wing (less Ailerons & Flaps)	(sq ft)			182.8				182.9
Ailerons	(sq ft)			18.4				18.3
Flaps	(sq ft)			34.8				34.8
Tail Area	(sq ft)	69.04	69.04	69.04	71.22	69.74	69.74	69.04	3
V Tail Area	(sq ft)	20.74	20.74	20.74	22.92	21.74	21.74	20.74	3
Fin	(sq ft)			7	9.18			7
Rudder	(sq ft)			13.74	13.74			13.74
H Tail Area	(sq ft)	48.3	48.3	48.3	48.3	48	48	48.3	3
Stabilizer	(sq ft)			30.86	30.86			30.86
Elevator	(sq ft)			17.44	17.44			17.44
Total Control Surf Area	(sq ft)			84.38				84.28
Length
Overall	(ft)	31.7	31.7	31.6	33.31	33.31	33.31	33.31
Fuselage	(ft)	27	27					27.96
Body	(ft)	31.6	31.6	31.6	33.31	33.31	33.31	33.31
Body Depth	(ft)	5.48	5.48	4.8	5.81	5.81	5.81	4.82
Body Width	(ft)	3.3	3.3	3.08	3.21	3.21	3.21	3.19
Fuel Tank Volume	(gal)	143	144	145	146	147	148	154
Wing Tanks	(gal)	85.5	85.5	85.5	85.5	85.5	85.5	88.0
FuselageTanks	(gal)	57.5	58.5	59.5	60.5	61.5	62.5	66.0
Oil Tank Volume	(gal)	13.3	13.3	13.3	13.3		13.3	10.0
Water Injection Fluid Tank Volume	(gal)
Wetted Area (sqf)	(sq ft)
Pwr Ldng	(lb/HP)		7.33
Wing Ldng	(lb/sq ft)		35.71
Struct. Des. GW	(lb)	7400	7400
Ultimate Load Factor	(G's)	12	12
Design Speed	(mph)		496
Not to Exceed Speed	(mph)

Total Struct Weight		2744	2550	2605	2578	2614	2580	2863
Total Wing		1126	1105	1132	1120	1126	1122	1131
Wing
Ailerons
Flaps
Fuselage Carry-Through
Tail		129	129	154	129	152	131	150
H Tail			91
Stabilizer
Elevator
V Tail			38
Fin
Rudder
Body + Eng Section + LG
Body + LG		1489	1316	1319	1329	1336	1327	1247
Body		794	792	767	784	787	779	759
Fuselage		449		418	435	437	434	424
Engine Section		345		349	349	350	345	335
Landing Gear		695	524	552	545	549	548	488
Mn Landing Gr			476
Tail/Nose Aux LG			48
Tail Hook
Booms
Nacelles
Total Propulsion Weight		2645	2641	2867	2731	2786	2756	1923
Engine w/ Accessories		1413	1416	1632	1397	1583	1418	1432
Engine(s) as Installed		1307	1311	1518	1324	1523	1337	1340
Accessories		106	105	114	73	60	81	92
Turbocharger(s)
Controls		26	23	8	36	34	35	29
Propeller(s)		383	384	386	418	418	418	417
2-Blade
3-Blade		383	384	386	418	418	418	417
4-Blade
Starting System		43	46	34	45	8	46	45
Water Injection System
Tanks
Piping Etc
Cooling System		294	292	306	294	305	294
Lube System		61	62	64	116	116	117
Tanks
Piping Etc
Fuel System		425	418	437	425	322	428
Tanks
Piping Etc
Total Sys. & Eqpmt.		680	936	1094	1058	1085	1050
Instruments		41	40	40	41	41	40
Surface Controls		101	103	98	97	100	98
Hydraulics		-	156	200	162	169	164
Electrical Equip		229	244	240	241	237	236
Electronics (Purple means incl in Furn/Gray in Useful Ld)		74	74	134	130	157	134
Arm Prov/Equipment & Armor			267	328	313	321	320
Furnishings		235	52	54	74	60	58
Anti-Ice (If not in Furn)
Other /Misc
Hoisting Gear
Floatation Gear
Armor Plate

Empty Wt		6069	6127	6566	6367	6485	6386	6206
Basic Mission Useful Load			2300
Crew			200
Equipment
Oil			135
Fuel			888
Fuel & Oil Trapped in Systems
Water Solution for Engine Injection
Bombs/Torp Etc
Radio (if Not Included in Empty Wt)
Nav Equipment
Oxygen System
Armament			956
Guns & Ammo			956
Guns			450
Ammo			506
Pyrotechnics
Camera
Other
Other Useful Load			121
Basic Mission GW			8427

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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