P-1 Hawk

Infobox Aircraft
name = P-1 Hawk
type = Fighter plane
manufacturer = Curtiss Aeroplane and Motor Company

---

caption = Curtiss P-1 Hawk
designer =
first flight = January 1923
introduced = 27 April 1923
retired =
status =
primary user = United States Army Air Corps
more users =
produced = 1925-1929
number built = 202 built as PW-8, P-1, P-2, P-3, P-5, AT-4 and AT-5
unit cost =
variants with their own articles = F6C Hawk P-6 Hawk

The Curtiss Model 34 - P-1 Hawk was a 1920s open-cockpit biplane fighter aircraft of the United States Army Air Corps. An earlier variant of the same aircraft had been designated PW-8 prior to 1925"US Military Aircraft Designations & Serials 1909-1979 by J.M. Andrade, (Midland Counties Publications, ISBN 0904597229) 1970, 252pp.] .

Design and development

PW-8

The Curtiss P-1 Hawk was the first US Army Air Service aircraft to be assigned the "P" (Pursuit) designation which replaced seven designations for pursuit aircraft, including "PW" (for "Pursuit, Water-cooled engine"). The P-1 was the production version of the Curtiss XPW-8B, an improved variant of the PW-8, 25 of which were operational with the Air Service's 17th Pursuit Squadron"The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0760734321), 1152 pp.] .

The PW-8 (Curtiss Model 33) had been acquired by the Air Service in 1924 after a competition with the Boeing Model 15, designated the "PW-9", to replace the existing Army fighter, the Boeing MB-3A. Although the PW-8 was faster than the "PW-9", it was otherwise out-performed by the Boeing plane, and its cooling system appeared to be more difficult to maintain and vulnerable in combat. However Assistant Chief of the Air Service Brig. Gen. Billy Mitchell agreed to purchase 25 PW-8s in return for assistance by Curtiss in making the Dawn-to-dusk transcontinental flight across the United States.

P-1

The prototype of the P-1, the XPW-8B, came about when the Air Service, which had selected the Boeing PW-9 over the PW-8 as its main production fighter, asked Curtiss to modify one of its three original XPW-8 prototypes with wings resembling those of the "PW-9". Curtiss designated the modified aircraft its Model 34A and returned it to the Air Service for evaluation, from which the service ordered it into production as the "P-1". The first production "P-1", serial number 25-410, was delivered on August 17, 1925, and was followed in successive years by the "P-1B" and "P-1C" variants with improved engines. The newest "P-1" variants remained in operational service until 1930.

The March 7, 1925 order for the "P-1" also requested five aircraft with the more powerful 500 hp (373 kW) Curtiss V-1400 engine installed. These were completed in January 1926. The first (SN 25-420) was then modified with a supercharger mounted on the right side of the fuselage nose, and whose turbine was driven by engine exhaust; the craft was designated XP-2Lloyd S. Jones, "U.S. Fighters" (Aero Publishers, Inc., 1975) pp. 14-15 ISBN 0-8168-9200-8] .

However, the Curtiss V-1400 engine did not perform up to expectations, with or without the supercharger, and so after a year in service, three of the standard P-2 Hawks had their engines replaced with the Curtiss V-1150 and were consequently redesignated as P-1s. The fifth machine (25-243) received a Curtiss V-1570 Conqueror engine and became the XP-6Lloyd S. Jones, "U.S. Fighters" (Aero Publishers, Inc., 1975) pp. 14-15 ISBN 0-8168-9200-8] .

93 production P-1s were brought into service in the P-1, P-1A, P-1B, and P-1C variants. 52 other P-1s, variants P-1D, P-1E, and P-1F, were made by conversion of other Hawk variants, primarily At-4 and At-5 trainers.

P-3 and P-5 test variants

The P-3 Hawk was similar to the P-1 Hawk but with a radial R-1340-3 Wasp radial engine. The first of the type, designated XP-3A, was the last "P-1A" (serial 26-300). Originally intended to be powered by a 390 hp Curtiss R-1454, the engine was deemed unsatisfactory and the 410 hp Pratt & Whitney R-1340 engine substituted. A second XP-3A (serial 28-189) included a cowling and spinner to reduce the drag due to the radial engine; entered in the National Air Races of 1929, its speed of 186.84 mph gave it second place in the Thompson trophy raceLloyd S. Jones, "U.S. Fighters" (Aero Publishers, Inc., 1975) pp. 14-15 ISBN 0-8168-9200-8] .

The remaining four craft were production P-3As, but primarily used to service test the Pratt & Whitney Wasp engine. In addition to the significant increase in drag, the radial engine also interfered with the pilot's view. Addition of a Townend ring cowling worsened the visibility problem, and had only a limited effect on speedLloyd S. Jones, "U.S. Fighters" (Aero Publishers, Inc., 1975) pp. 14-15 ISBN 0-8168-9200-8] . It was also tested with various types of deep-chord NACA cowls"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .

Five P-5 Superhawks, similar to the "P-1C" but with a turbocharged V-1150-3 engine, were delivered in 1928. They had a top speed of 166 mph (267 km/h) at 25,000 ft (7620 m), considerably higher than the maximum ceiling of the "P-1A", but their low-level performance was inferior ["Weapons and Warfare volume 12" Editor Bernard Fitzsimons, (BPC Publishing Ltd., ISBN 0839361750), 1978, page 1255.]

AT-4 and AT-5 trainers

Two single-seat advanced trainer variants were placed into production, the AT-4 and AT-5A, using Wright-Hispano engines. All were re-engined with Curtiss D-12D engines and reverted to use as fighters, designated "P-1D" and "P-1F" respectively. Five "AT-4/XAT-5" test variants were re-classified as P-1E"The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .

A total of 202 "PW-8", "P-1", "P-2", "P-3", "P-4", "P-5", "AT-4", and "AT-5" airplanes were delivered"U.S. Army Aircraft 1908-1946" by James C. Fahey, 1946, 64pp.] .

Operational history

On June 23, 1924, taking off at 3:58 A.M., Army test pilot 1st Lt. Russell Maughan left Mitchel Field, New York, in PW-8 24-204, modified with additional fuel and oil tanks, made a dawn-to-dusk transcontinental flight across the US ["The Encyclopedia of Military Aircraft" by Robert Jackson, (Parragon Publishing, ISBN 1405424656), 2003, 384 pp.] . Refueling five times, he landed at Crissy Field, San Francisco, California, at 9:46 p.m., one minute before dusk, covering 2,670 miles in 20 hours and 48 minutes. His flight time included four planned 30-minute stops at McCook Field, Ohio; Saint Joseph, Missouri; Cheyenne, Wyoming; and Salduro Siding, Utah; and an unplanned stop in North Platte, Nebraska for additional fuel when a muddy field in Missouri did not permit him to take on a full load. He also lost an hour at McCook to repair a broken fuel valve after an over-eager mechanic had over-torqued the valve, damaging it.

The original fifteen "P-1s" served in the 27th and 94th Pursuit Squadrons, 1st Pursuit Group, Selfridge Field, Michigan. The first Hawk to serve with the Air Corps in quantity was the "P-1A" (17th, 27th, and 94th Pursuit Squadrons) beginning in 1925. In October 1928 the largest order of 33 "P-1s" was made. These were delivered by April 1929 as P-1Cs"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .

The "AT-4" and "AT-5" trainer variants served with the 43rd Pursuit Squadron (School) at Kelly Field, Texas"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .

Variants

While a total of 202 Hawks were built in the basic variants PW-8, P-1, P-2, P-3, P-5, AT-4 and AT-5, conversions resulted in 148 having a P-1 designation.;XPW-8:3 manufactured, one modified to "XPW-8A" and later "XPW-8B" standard, one converted to "CO-X" two-seat observation aircraft"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .;PW-8:25 produced and flown by 17th Pursuit Squadron;XPW-8A:An "XPW-8" converted with a new cooling system and modified wings for trials"The Complete Book of Fighters" [http://ec1.images-amazon.com/images/I/21RSY79BDHL.jpgcover] Editors: William Green & Gordon Swanborough (Barnes & Noble Books New York, 1998, ISBN 0760709041), 608 pp.] .;XPW-8B:Model 34 - The "XPW-8A" fitted with single-bay tapered wing as prototype for the "P-1" series"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .;P-1:Model 34A - Production version of the "XPW-8B" with modified rudder and additional wing center strut, and Clark Y aerofoil, powered by 435hp Curtis V-1150-1 (D12), 10 built"United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.] .;P-1A:Model 34G - "P-1" with 3-inch fuselage stretch, larger wheels and revised fuel system, 25 built with D-12C engine and three conversions from "P-2". Final two converted to XAT-4 Trainer and XP-3 racer prototypes. Delivered in 1926"The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .;XP-1A:One "P-1A" used for development trials.;P-1B:Model 34I - 25 produced with Curtis V-1150-3 (D-12D) engine. Increased weight reduced performance. Delivered 1927.;P-1C:Model 34O - 33 built with Curtis V-1150-5 (D-12E) engine. Increased weight further decreased performance. delivered 1927-28.;XP-1C:One "P-1C" fitted with a revised radiator.;P-1D:24 conversions from AT-4 trainers, re-engined with Curtis V-1150-3 (D-12D) engines.;P-1E:4 conversion from "AT-5" trainers re-engined with 440hp V-1150-3 built as "AT-4s" and converted to XAT-5 prototype. All re-engined and converted to P-1E.;P-1F:24 conversions from "AT-5A" trainers, one conversion from XP-21A, all re-engined with a 440hp Curtis V-1150-3 in 1929.;P-2:Model 34B - "P-1" with a 500hp Curtiss V-1400, five built. 3 later converted to P-1A and one re-engined with the Curtiss V-1570-1 as the XP-6"The Complete Book of Fighters" [http://ec1.images-amazon.com/images/I/21RSY79BDHL.jpgcover] Editors: William Green & Gordon Swanborough (Barnes & Noble Books New York, 1998, ISBN 0760709041), 608 pp.] .;XP-3:Radial engined version, one converted from a "P-1A" with 390hp Curtiss R-1454 engine, later converted to XP-3A.;XP-3A:XP-3 re-engined with a 410hp Pratt & Whitney R-1340-1;P-3A:Model 34N - five production aircraft to the "AT-5A" design with a 410hp Pratt & Whitney R-1340-7.;XP-4:"P-1A" modified with a supercharged 510 hp Packard 1A-1530 engine"U.S. Army Aircraft 1908-1946" by James C. Fahey, 1946, 64pp.] .;XP-5:"P-1A" version with a 435hp Curtiss V-1150-3 engine"U.S. Army Aircraft 1908-1946" by James C. Fahey, 1946, 64pp.] .;P-5:Model 34L - four built, same as XP-5 later modified with the Curtiss D-12F engine"U.S. Army Aircraft 1908-1946" by James C. Fahey, 1946, 64pp.] .;XAT-4:Model 34J - "P-1A" re-engined with a 180hp Wright-Hispano E as an advanced trainer"The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .;AT-4:Production version of the "XAT-4", 40 ordered, first 35 were converted in 1929 to "P-1Ds" with the Curtiss D-12 engine, and the remainder completed as "AT-5s""The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .;AT-5:Model 34J - five aircraft originally to "AT-4s" re-engined with a 220hp Wright J-5, later converted to "P-1Es""The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .;AT-5A:Model 34M - 31 aircraft based on the "P-1B" with a lengthened fuselage, later converted to "P-1Fs""The Complete Encyclopedia of World Aircraft" [http://images.barnesandnoble.com/images/5490000/5496066.gifcover] Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.] .

All variants increased in weight with each succeeding model, resulting in slight reductions in performance with each.

Operators

;BOL
* Four P-1s were supplied to Bolivia"The Complete Book of Fighters" [http://ec1.images-amazon.com/images/I/21RSY79BDHL.jpgcover] Editors: William Green & Gordon Swanborough (Barnes & Noble Books New York, 1998, ISBN 0760709041), 608 pp.] .;CHL
* Eight P-1As and eight P-1Bs went to Chile"The Complete Book of Fighters" [http://ec1.images-amazon.com/images/I/21RSY79BDHL.jpgcover] Editors: William Green & Gordon Swanborough (Barnes & Noble Books New York, 1998, ISBN 0760709041), 608 pp.] .;JPN
*One P-1A went to Japan"The Complete Book of Fighters" [http://ec1.images-amazon.com/images/I/21RSY79BDHL.jpgcover] Editors: William Green & Gordon Swanborough (Barnes & Noble Books New York, 1998, ISBN 0760709041), 608 pp.] .;USA
*United States Army Air Corps

pecifications (P-1C)

aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref="The Complete Encyclopedia of World Aircraft" Editors: Paul Eden & Soph Moeng, 2002, ISBN 0760734321, page 506.
crew= one, pilot
capacity=
length main= 23.0 ft
length alt= 7.01 m
span main= 31.5 ft
span alt= 9.6 m
height main= 8.75 ft
height alt= 2.67 m
area main= 252 ft²
area alt= 23.41 m²
airfoil= Clark Y
empty weight main= 2,195 lb
empty weight alt= 996 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 2,937 lb
max takeoff weight alt= 1,349 kg
more general=
engine (prop)= Curtiss V-1150-3
type of prop= liquid-cooled V12 engine
number of props= 1
power main= 435 hp
power alt= 324.5 kW
power original=
max speed main= 155 mph
max speed alt= 249 km/h
cruise speed main= 123 mph
cruise speed alt= 198 km/h
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 300 mi
range alt= 483 km
ceiling main= 20,800 ft
ceiling alt= 6,340 m
climb rate main= 1,460 ft/min
climb rate alt= 7.42 m/s
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
* two .30 cal (7.62 mm) fixed forward-firing Browning machine guns
avionics=

References

External links

* [http://home.att.net/~jbaugher1/p1.html Joseph Baugher "P-1" page with sources]

ee also

aircontent
related=
similar aircraft=
lists=
* List of military aircraft of the United States
* List of fighter aircraft