Curtiss YP-20

Prototype biplane fighter

YP-20

Parked YP-20
Role	Biplane fighter Type of aircraft
Manufacturer	Curtiss Aeroplane and Motor Company
Primary user	United States Army Air Service
Number built	1

The Curtiss YP-20 was an American biplane fighter project developed by Curtiss for the United States Army Air Service.

Design and development

In 1929, three Curtiss P-11 Hawks were ordered with 600 hp (447 kW) Curtiss H-1640 Chieftain engines. These proved a failure, and before completion, the third was converted to use a 9-cylinder 575 hp (429 kW) Wright Cyclone, being completed as the YP-20. Testing with the R1820 was prolonged, so the Army's intention to promptly switch to a Curtiss V-1570 Conqueror engine and redesignate the aircraft XP-22 was dropped; another P-11 was chosen for that instead.

Except for the engine change and its Townend ring cowling, the YP-20 was not drastically different from the P-6 from which both it and the P-11 derived, though the YP-20 had more fin and less rudder area,^[1] and featured a steerable tailwheel, rather than the original skid.^[2] Later, a crankcase cover, gear strut fairings, and wheel pants were added.

In June 1931, the AAC held a competition to evaluate the P-6, P-12, XP-22, and YP-20. The XP-22 came out the winner, but the YP-20 was given a nose and landing gear graft from the XP-22, becoming the XP-6E (P-6E prototype). With the addition of a supercharger and an enclosed cockpit, it was tested as the XP-6F.

Operators

United States

United States Army Air Service

Specifications (original YP-20)

Data from Curtiss Aircraft 1907–1947^[3]

General characteristics

Crew: 1
Length: 23 ft 0 in (7.01 m)
Wingspan: 31 ft 6 in (9.60 m)
Height: 9 ft 3 in (2.82 m)
Wing area: 252 sq ft (23.4 m²)
Airfoil: 'Clark Y^[4]
Empty weight: 2,523 lb (1,144 kg)
Gross weight: 3,231 lb (1,466 kg)
Powerplant: 1 × Wright R-1820-9 Cyclone 9-cylinder air-cooled radial piston engine, 650 hp (480 kW)
Propellers: 2-bladed fixed-pitch propeller

Performance

Maximum speed: 188.6 mph (303.5 km/h, 163.9 kn)
Cruise speed: 150 mph (240 km/h, 130 kn)
Range: 237 mi (381 km, 206 nmi)
Service ceiling: 27,800 ft (8,500 m)
Rate of climb: 2,600 ft/min (13 m/s)

Armament

Guns: 2 × fixed forward-firing 0.300 in (7.62 mm) M1919 Browning machine guns

References

^ Fitzsimons, Bernard, ed. Illustrated Encyclopedia of Weapons and Warfare (London: Phoebus, 1978), Volume 12, p.1255.
^ Fitzsimons, p.1255.
^ Bowers, Peter M. (1979). Curtiss aircraft, 1907-1947. London: Putnam. pp. 256–266. ISBN 0370100298.
^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.

Fitzsimons, Bernard, ed. Illustrated Encyclopedia of Weapons and Warfare. Volume 12, pp. 1255–6, "Hawk, Curtiss Models 34 and 35 (P-1 to P-6 and F6C". London: Phoebus Publishing, 1978.
Donald, David, ed. Encyclopedia of World Aircraft. Etobicoke, ON: Prospero Books, 1997.
Jones, Lloyd S. U.S. Fighters. Fallbrook, CA: Aero Publishers, 1975.

Curtiss and Curtiss-Wright aircraft

Manufacturer
designations

Early types	Golden Flier Reims Racer Beachey Special
Model letters	C D E F FL GS H HA HS J JN -5 -6H K L MF N NC O R S T
Model numbers	1 B F 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 K/P 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 A B 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 I P S 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
"L" series	L-17 L-18 L-19 L-22 L-41 L-44 L-72 L-79 L-85 L-115 L-117 L-710
"CA" series	CA-1
"CR" series	CR-1 CR-2
"CW" series	CW-1 CW-2 CW-3 CW-4 CW-5 CW-6 CW-8 CW-9 CW-10 CW-11 CW-12 CW-14 CW-15 CW-16 CW-17 CW-18² CW-19 CW-20 CW-21 CW-22 CW-23 CW-24 CW-25 CW-26 CW-27 CW-28 CW-29 CW-32 CW-33 CW-40
"P" series	P-200 P-202 P-212 P-218 P-219 P-222 P-223 P-224 P-225 P-227 P-228 P-229 P-232 P-235 P-238 P-239 P-240 P-241 P-243 P-244 P-245 P-247 P-248 P-249 P-250 P-251 P-252 P-253 P-254 P-255 P-256 P-257 P-259 P-261 P-264 P-268 P-269 P-272 P-273 P-274 P-275 P-276 P-277 P-278 P-279 P-280 P-282 P-283 P-291 P-292 P-293 P-295 P-296 P-297 P-298 P-299 P-302 P-303 P-304 P-305 P-306 P-307 P-509 P-517 P-518 P-538 P-539 P-541 P-545 P-551 P-558 P-565 P-586 P-588 P-592
"X" series	X-100 X-200 X-300 X-410 X-425

Operator and role

Civil

Experimental	No. 1 Model C SX-5-1 Tanager
Racers and record	No. 2 Cox Racer CW-B-14R
Airliners	Eagle Condor 18 Condor II Kingbird Thrush Commando
Utility	Model D Model E Model F Carrier Pigeon Falcon Robin Lark 6B CW-12 CW-14 Sportsman CW-15 Sedan CW-16 CW-19W

Army

Ground attack	A-3 A-4 A-5 A-6 A-8 YA-10 A-12 YA-14 A-18 A-25 A-40 XA-43
Bombers	NBS-1 B-2 XNBS-4
Transports	XC-10 C-30 Condor C-46 Commando C-55 Commando C-76 C-113 Commando
Fighters	S 18 PN-1 PW-8 P-1 to P-5 P-6 XP-10 P-11 P-14² P-17 XP-18² XP-19² YP-20 XP-21 XP-22 XP-23 XP-31 P-36 YP-37 P-40 XP-42 XP-46 XP-53 XP-55 YP-60 XP-62 XP-71 XP-87
Observation	O-1 O-11 O-12 O-13 O-16 O-18 O-24² O-26 XO-30² O-39 O-40 O-52
Racers	R-6 R-8
Trainers	J L JN Fledgling AT-4 Hawk AT-5 Hawk BT-4 AT-9 Jeep
Experimental	X-19
Licensed	USAO-1 NBS-1/Model 30

Navy

Bombers	CT BFC BF2C SBC SB2C XSB3C² XBTC XBT2C
Fighters	HA GS TS-1 FC F2C F3C F4C F5C¹ F6C F7C F8C F9C F10C F11C XF12C F13C XF14C XF15C
Observation/scout	CS/SC S2C XS3C S4C SC OC O2C O3C SOC SO2C SO3C
Trainers	N-9 N2C SNC
Transports	RC R4C R5C
Maritime patrol	H-16 F5L HS-1L & HS-2L
Racers and record	NC CR R2C R3C

Export

Bombers	Canada CW-14 Osprey
Maritime patrol	H-2, H-4, H-8 and H-16 F5L HS-2L
Fighters	CW-17 Pursuit Osprey² CW-21 Demon
Trainers	Canuck CW-14 Osprey CW-16 CW-18² CW-22

¹ Designation skipped ² Not built

USAAS/USAAC/USAAF/USAF fighter designations 1924–1962, and Tri-Service post-1962 systems

1924 sequences
(1924–1962)

Pursuit (1924–1948)	P-1 P-2 P-3 P-4³ Curtiss P-4 Boeing P-4 P-5 P-6 P-7 P-8 P-9 P-10 P-11 P-12 P-13 P-14 P-15 P-16 P-17 P-18 P-19 P-20 P-21 P-22 P-23 P-24 P-25 P-26 P-27 P-28 P-29 P-30 P-31 P-32 P-33 P-34 P-35 P-36 P-37 P-38 P-39 P-39E P-40 P-41 P-42 P-43 P-44 P-45 P-46 P-47 P-48 P-49 P-50 P-51 P-52 P-53 P-54 P-55 P-56 P-57 P-58 P-59³ XP-59 P-59 P-60 P-61 P-62 P-63 P-64 P-65 P-66 P-67 P-68 P-69 P-70 P-71 P-72 P-73² P-74¹ P-75 P-76 P-77 P-78 P-79 P-80 P-81 P-82 P-83 P-84 P-85 P-86 P-87 P-88 P-89 P-90 P-91 P-92
Fighter (1948–1962)	F-38 F-39 F-40 F-47 F-51 F-59 F-61 RF-61C F-63 F-80 F-81 F-82 F-83 F-84 F-84F/J F-84H F-85 F-86 F-86C F-86D/G/K/L F-87 F-88 F-89 F-90 F-91 F-92 F-93 F-94 F-95 F-96 F-97 F-98 F-99 F-100 F-100B F-101 F-102 F-102B F-103 F-104 XF-104 F-104S NF-104A F-105 F-106³ XF-106 F-106 F-107 F-108 F-109² F-110 F-111 F-111B F-111C F-111K AFTI/F-111A EF-111A
Pursuit, Biplace	PB-1 PB-2 PB-3
Fighter, Multiplace	FM-1 FM-2
Non-sequential	F-24 P-322 P-400

Tri-service sequence
(1962–present)

Main sequence	F-1 F-1C/D F-1E/F F-2 F-3 F-4 F-4K/M F-5 G F-6 F-7 F-8 F-9 F-9F–J F-10 F-11 F-12 F-12C² F-13¹ F-14 F-15 F-15E F-15EX F-15J F-15 STOL/MTD F-16 F-16XL NF-16D F-17 F/A-18 F/A-18E/F EA-18G F-19¹ F-20 F-21 F-22 YF-22 FB-22 F-23
Non-sequential	F-35 F-35I X-35 F-117