Boeing P-12

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P-12 / F4B
Boeing P-12E at the National Museum of the United States Air Force, in markings of 6th Pursuit Squadron, 18th PG, Wheeler Field, Hawaii
RoleFighter aircraft
ManufacturerBoeing Aircraft Company
First flight25 June 1928
Introduction1930
Retired1949 Brazilian Air Force [1]
Primary usersUnited States Army Air Corps
United States Navy
Philippine Army Air Corps
Royal Thai Air Force
Produced19291932
Number built586[2]
*366 P-12
*187 F4B
*33 demonstrators and exports
 
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P-12 / F4B
Boeing P-12E at the National Museum of the United States Air Force, in markings of 6th Pursuit Squadron, 18th PG, Wheeler Field, Hawaii
RoleFighter aircraft
ManufacturerBoeing Aircraft Company
First flight25 June 1928
Introduction1930
Retired1949 Brazilian Air Force [1]
Primary usersUnited States Army Air Corps
United States Navy
Philippine Army Air Corps
Royal Thai Air Force
Produced19291932
Number built586[2]
*366 P-12
*187 F4B
*33 demonstrators and exports

The Boeing P-12 (P=Pursuit) or F4B was an American pursuit aircraft that was operated by the United States Army Air Corps and United States Navy.

Contents

Design and development

Boeing developed the aircraft as a private venture to replace the Boeing F3B and Boeing F2B with the United States Navy that was the first flight of the P-12 took place on 25 June 1928. The new aircraft was smaller, lighter and more agile than the ones it replaced but still used the Wasp engine of the F3B. This resulted in a higher top speed and overall better performance. As result of Navy evaluation 27 were ordered as the F4B-1, later evaluation by the United States Army Air Corps resulted in orders with the designation P-12. Boeing supplied the USAAC with 366 P-12s between 1929 and 1932. Production of all variants totalled 586.

Operational history

P-12s were flown by the 17th Pursuit Group (34th, 73rd, and 95th Pursuit Squadrons) at March Field, California, and the 20th Pursuit Group (55th, 77th and 79th Pursuit Squadrons) at Barksdale Field, Louisiana. Older P-12s were used by groups overseas: the 4th Composite Group (3rd Pursuit Squadron) in the Philippines, the 16th Pursuit Group (24th, 29th, 74th, and 79th Pursuit Squadrons) in the Canal Zone, and the 18th Pursuit Group (6th and 19th Pursuit Squadrons) in Hawaii.

The P-12 remained in service with first-line pursuit groups until replaced by Boeing P-26s in 1934–1935. Survivors were relegated to training duties until 1941, when most were grounded and assigned to mechanics's schools.

Civil and commercial models

Commencing in 1929 Boeing produced four commercial and export variants of the Model 100 with an affinity to both the Army P-12 and Navy F4B-1. The principal differences were the deletion of standard U.S. military equipment and the installation of the fuel tank in the center section of the upper wing.

Model 100

The first Model 100, the commercial counterpart of the F4B-1/P-12 Model 100 flew on October 8th 1929 and was sold to the Bureau of Air Commerce (now the FAA) with the Government aircraft registration NS-21.

The second, NX872H, was sold to Pratt & Whitney for use as an engine test bed; apart from the original R-1340 "Wasp", this airplane also flew the R-98S "Wasp Junior", the R-1535 "Twin Wasp Junior" and the R-1690 "Hornet" engines. It was then sold to stunt pilot Milo Burcham who used it for display flying between 1933 and 1941 as NC-872H with distinctive modifications. The space between the undercarriage legs was faired in, low pressure tires fitted, and metal paneling replacing the fuselage fabric. At the time of writing (1964) the airplane is currently owned by Paul Mantz of Santa Ana, California.

The third Model 100 has had the most varied career and has carried every possible combination of U.S. civil registration, commencing with the plain 873H and passing through C, AT, NR, NX to N873H. It was used at the factory for several years as a test machine and demonstrator, and was then sent to the Boeing School of Aeronautics at Oakland, California, for use as an advanced trainer. It was acquired about 1936 by Paul Mantz for display and movie flying and is still being used for such. It is now powered by a war surplus Wasp Junior driving a controllable-pitch propeller.

Last of the Model 100s, NX874H, was also used as a company demonstrator and was eventually sold to the Mitsui Company of Japan.

Model 100A

The Model 100A was a special convertible two-seat version of the basic Model 100 built to the special order of Mr. Howard Hughes. Hughes undertook many extensive modifications before the aircraft was sold to Col. Arthur Goebel as a single seater. Registered 247K it was destroyed in 1957.

Model 100E

Two Model 100Es were built for Siam (now Thailand) and were export versions of the P-12E. Owing to a ruling that export of aircraft currently in production for U.S. Forces could not be undertaken, the Boeing Model 234 designation was changed to 100E though general structure and performance was similar to that of the P-12E. Both 100Es were delivered in a dismantled state on 10 November 1931. The last surviving example (taken over by the Japanese during World War II), is currently preserved in the Thai Aeronautical Museum at Bangkok.

Model 100F

The Model 100F was a one-off commercial equivalent of the P-12F delivered to Pratt & Whitney for engine testing. First engine fitted was the 700 hp R-1535 Twin Wasp Junior and with this was flown on 20 June 1932. So great was the diameter of the propeller used that both take-off and landing had to be performed in the "three-point" attitude to maintain ground clearance.

The 100F also flew with the Hornet and Wasp engines. On one occasion it flew with each of the engines during the course of a single day as a demonstration of quick engine-changing techniques. Because of the different engine weights, the balance of the aircraft was corrected during these engine changes by use of a sliding weight in the fuselage between the cockpit and tail. On a test flight the pilot lost consciousness due to a failure in the oxygen supply and the 100F fell into a spin. Not being designed to withstand the loads imposed by these gyrations, the weight broke loose and destroyed the flying controls - preventing recovery from the spin.

Variants

Boeing P-12
Boeing P-12 with Captain Ira Eaker
Boeing F4B of VF-5 squadron (Navy version of P-12)
Model 83
One prototype with spreader bar landing gear and 425 hp Pratt & Whitney R-1340-8 engine, later designated XF4B-1 for Navy evaluation.
Model 89
One prototype with split-axle undercarriage and provision for a 500 lb bomb on ventral rack, later designated XF4B-1 for Navy evaluation.
P-12
Model 102, Army version of the F4B-1 with a 450 hp R-1340-7 engine, nine built.
XP-12A
10th built P-12 with NACA cowl a 525 hp R-1340-9 engine and shorter undercarriage, one built.
P-12B
Model 102B, as P-12 with larger mainwheels and improvements tested on XP-12A, 90 built.
P-12C
Model 222, as P-12B with ring cowl and spread-bar undercarriage, 96 built.
P-12D
Model 234, as P-12C with a 525 hp R-1340-17 engine, 35 built.
P-12E
Model 234, as P-12D with semi-monocoque metal fuselage, redesigned vertical tail surfaces, some were later fitted with tailwheels instead of skids, 110 built.
P-12F
Model 251, as P-12E with a 600 hp R-1340-19 engine, 25 built.
XP-12G
P-12B modified with a R-1340-15 engine with side-type supercharger, one converted.
XP-12H
P-12D modified with a GISR-1340E experimental engine, one converted.
P-12J
P-12E modified with a 575 hp R-1340-23 engine, and special bomb sight, one conversion.
YP-12K
P-12E and P-12J re-engined with a fuel injected SR-1340E engine, seven temporary conversions.
XP-12L
YP-12K temporary fitted with a F-2 supercharger, one converted.
A-5
designation for proposed use of P-12 as a radio-controlled target drone (cancelled)
XF4B-1
Designation given to two prototypes for Navy evaluation, the former Model 83 and the former Model 89.[3]
F4B-1
Boeing Model 99 for the United States Navy, split axle landing gear and ventral bomb rack, 27 built.[4]
F4B-1A
One F4B-1 converted to unarmed executive transport for the Assistant Secretary of the Navy, fuel tank moved to upper wing centre section.[5]
F4B-2
Boeing Model 223, spreader bar landing gear, frise ailerons, tailwheel replacing skid, 46 built.[6]
F4B-3
Boeing Model 235, as F4B-2 but with semi-monocoque metal fuselage and equipment changes, 21 built.[7]
F4B-4
Boeing Model 235, as F4B-3 but with redesigned vertical tail surfaces, 550 hp R-1340-16 engine, underwing racks for two 116 lb bombs, last 45 built had an enlarged headrest housing a life raft, 92 built and one built from spares.[8]
F4B-4A
23 assorted P-12 aircraft transferred from USAAC for use as a radio-controlled target aircraft.[9]
Model 100
Civil version of the F4B-1, four built.[10]
Model 100A
Two-seat civil version for Howard Hughes, later converted to a single-seater, one built.[11]
Model 100D
One Model 100 temporary used as a P-12 demonstrator.[12]
Model 100E
Export version of the P-12E for the Siamese Air Force, two built, one later transferred to the Japanese Navy under the designation AXB.[13]
Model 100F
One civil variant of the P-12F sold to Pratt & Whitney as an engine test bed.[14]
Model 218
Prototype of the P-12E/F4B-3 variant, after evaluation sold to the Chinese Air Force.[15]
Model 256
Export version of the F4B-4 for Brazilian Navy, 14 built.[16]
Model 267
Export version for Brazil with an F4B-3 fuselage and P-12E wings, nine built.[17]

Operators

Boeing 100Eat the Royal Thai Air Force Museum
 Brazil
 China
 Philippines
 Spain
 Thailand
 United States

Aircraft on display

Specifications (P-12E)

Data from Bowers 1989

General characteristics

Performance

Armament

See also

Related lists

References

Notes
  1. ^ "Historical Listings: Brazil, (BRZ)."] World Air Forces. Retrieved: 19 May 2011.
  2. ^ "F4B." VF31.com. Retrieved: 10 June 2011.
  3. ^ Bowers 1989, p. 166.
  4. ^ Bowers 1989, p. 168.
  5. ^ Bowers 1989, p. 170.
  6. ^ Bowers 1989, p. 181.
  7. ^ Bowers 1989, pp. 187–188.
  8. ^ Bowers 1989, pp. 188–189.
  9. ^ Bowers 1989, pp. 189–190.
  10. ^ Bowers 1989, pp. 171–172.
  11. ^ Bowers 1989, pp. 173–174.
  12. ^ Bowers 1989, p. 175.
  13. ^ Bowers 1989, pp. 175–176.
  14. ^ Bowers 1989, p. 176.
  15. ^ Bowers, 1989. pp. 179–180.
  16. ^ Bowers 1989, pp. 192–193.
  17. ^ Bowers 1989, p. 193.
  18. ^ Angelucci 1983, p. 120.
Bibliography
  • Angelucci, Enzo. The Rand McNally Encyclopedia of Military Aircraft, 1914–1980. San Diego, California: The Military Press, 1983. ISBN 0-517-41021-4.
  • Baugher, Joe. "Boeing P-12." American Military Aircraft, 6 June 1998. Retrieved: 10 June 2011.</ref>
  • Bowers, Peter M. Boeing aircraft since 1916. London: Putnam Aeronautical Books, 1989. ISBN 0-85177-804-6.

External links