Boeing Model 15

{{Short description|American fighter aircraft}}  {{Infobox aircraft |name = PW-9/FB |image = File:Boeing_FB-5(2).jpg |caption = USMC Naval variant, Boeing FB-5 of VM-3M [[VMFA-232]] |type = Pursuit fighter (PW-9)<br/>Carrier Fighter (FB series) |manufacturer = Boeing |designer = |first_flight = 2 June 1923 |introduction = 1923 |retired = |status = |primary_user = [[United States Army Air Service]] |more_users = [[United States Navy]] <br/> [[United States Marine Corps]] |number_built = 158 |unit cost = |developed_from = |variants = [[Boeing XP-4]] }}

The '''Boeing Model 15''' is a [[United States]] single-seat open-cockpit [[biplane]] [[fighter aircraft]] of the 1920s, manufactured by the [[Boeing]] company. The Model 15 saw service with the [[United States Army Air Service]] (as the '''PW-9''' series) and with the [[United States Navy]] as a [[aircraft carrier|carrier-based]] fighter (as the '''FB''' series).

==Design and development== The design of the Model 15 was based on studies of the [[Fokker D.VII]],<ref name="Baugher">{{cite web|last1=Baugher|first1=Joe|title=Boeing PW-9|url=http://www.joebaugher.com/usaf_fighters/pw9.html|website=www.joebaugher.com|access-date=2014-07-01}}</ref> of which 142 were brought back to the U.S. for evaluation as part of the [[Armistice with Germany (Compiègne)|Armistice]] Agreement ending [[World War I]]. Many of the features were similar. The Model 15 had a [[fuselage]] of welded steel tubing braced with piano wire, while the tapered single bay wings were fabric on a wooden frame, with spruce and mahogany wing spars and three-ply wood ribs. Wing struts were changed from the normal wood used in Boeing designs to streamlined steel tubes. The landing gear had a straight axle, streamlined into a small {{cvt|16|in}} [[chord (aircraft)|chord]] wing.<ref name="Bowersp81"/>

The original engine was a {{cvt|300|hp|kW|lk=in}} Wright-Hispano, but when the {{cvt|435|hp}} [[Radiator (engine cooling)|liquid-cooled]] [[Curtiss D-12]] became available the aircraft was redesigned, moving the [[Radiator (engine cooling)|radiator]] from the nose to a "tunnel" under the engine.<ref name="Baugher" /> Along with some other minor design changes to the wings, the design was finalized on January 10, 1922.<ref name="Bowersp81"/>

The Army expressed interest in the new design, and agreed to provide armament, powerplants, and test the aircraft, while leaving Boeing the rights to the aircraft and design. The contract was signed on April 4, 1923<ref name="Baugher" /> and the first prototype, designated ''XPW-9'' for "Experimental Pursuit, Water-cooled engine", flew on June 2, 1923.<ref name="bowersp82"/> The XPW-9 competed with the [[Curtiss P-1 Hawk|Curtiss Model 33]] for contracts for a pursuit aircraft to replace the [[Thomas-Morse MB-3]]A in the [[United States Army Air Service]].<ref name="bowersp82">Bowers 1989, p.82.</ref>

Ultimately, both models were accepted; the Curtiss aircraft was designated '''PW-8''' and the Model 15 '''PW-9'''. The Air Service preferred the PW-9, which outperformed the PW-8 in all performance aspects except speed, and was built on a more rugged and easier to maintain design, ordering 113 aircraft (only 25 PW-8s were procured).<ref name="Baugher" /> A naval version was also developed, designated '''FB''', and 44 aircraft produced.

==Operational history== Deliveries of the first 25 PW-9s began on October 30, 1925.<ref name="bowersp69"/> Boeing delivered a total of 114 PW-9s of all variants including prototypes to the [[United States Army Air Corps]] between 1925 and February 1931. Virtually all PW-9s served with overseas units, in [[Hawaii]] with the 5th Composite Group at [[Ford Island|Luke Field]] and later the 18th Pursuit Group at [[Wheeler Army Airfield|Wheeler Field]],<ref>{{cite journal|journal=AAHS Journal|date=Spring 1985|title=Woolaroc!|author=Ed Phillips}}</ref> and in the [[Philippines]] with the 4th Composite Group at [[Clark Air Base|Clark Field]], [[Luzon]]. PW-9s equipped the 3rd, 6th, and 19th Pursuit Squadrons between 1925 and 1931.

The FB-1, of which the Navy ordered 16 but received only ten between December 1 and 22, 1924,<ref name="bowersp84">Bowers 1989, p. 84.</ref> was not modified for naval operations (for instance, no [[arresting hook]]), and was assigned to Marine Corps squadrons [[VF-1M]], [[VF-2M]], and [[VF-3M]], being deployed to [[China]] in support of the Marine Expeditionary Force.<ref name="Swan&bowersp55">Swanborough and Bowers 1976, p.55.</ref> Two additional planes—designated FB-2—were altered to operate on the carrier {{USS|Langley|CV-1|2}} with the addition of arresting gear and a straight-across axle for the landing gear. These went into service with [[VF-2 (1927–1942)|VF-2]] in December 1925. Generally satisfactory results led to an order for 27 FB-5s, which became the Navy's first fighters intended specifically for carrier operation. They were upgraded to {{cvt|525|hp}} [[Packard 2A-1500]] engines, and sported a row of hooks on the bottom of the axle, used to guide the plane via cables on the deck. The FB-5 first flew October 7, 1926 and was delivered to the Navy beginning in the following January, carried on barges in [[Puget Sound]] from Boeing's factory to ''Langley'' anchored in Seattle's harbor. Hoisted aboard, their first official flights were from the carrier's deck.<ref name="Swan&Bowersp56">Swanborough and Bowers 1976, p.56</ref>

==Production history== Of the 158 aircraft built, 147 were standard production aircraft and the remaining were aircraft developed for specific interests.{{cn|date=March 2024}}

The production runs are shown below with the PW designations for Army aircraft and the FB designations being for the Navy. {| class="wikitable" |- ! Number Built !! Model !! Years Built !! Engine |- | 30 || PW-9 || 1925-1926 || [[Curtiss D-12]] |- | 24 || PW-9A || 1926-1927 || Curtiss D-12C |- | 40 || PW-9C || 1927-1928 || Curtiss D-12D |- | 16 || PW-9D || 1928-1934 || Curtiss D-12D |- | 10 || FB-1 || 1924 || Curtiss D-12 |- | 27 || FB-5 || 1927- || Packard 2A-1500 |}

==Variants== ;XPW-9 :Three prototypes built for Air Service evaluation. First aircraft scrapped at McCook Field on February 21, 1925, second static tested in October 1928 and the third was still flying in December 1928.<ref name="bowersp69">Bowers 1966, p.69.</ref>

;PW-9 :30 produced 1925-26, first production variant, D-12 engine.<ref name="Baugher" />

;PW-9A :24 produced 1926-27, D-12C engine.<ref name="Baugher" />

;PW-9B :One modified PW-9A, delivered as PW-9B in 1927.<ref name="Baugher" />

;PW-9C :40 produced 1927-28, D-12D engine.<ref name="Baugher" />

;PW-9D :16 produced 1928-34, final production variant.<ref name="Baugher" />

;[[Boeing XP-4|XP-4]] :Designation of one PW-9 (ser no. 25-324) re-engined with a {{cvt|510|hp}} Packard 1A-1500 engine. Boeing Model 58.

;AT-3 :Designation of one PW-9A (ser no. 26-374) converted to single-seat trainer with a Wright-Hispano engine.<ref name="Baugher" /> [[File:Boeing FB-1.jpg|thumb|right|FB-1]] ;FB-1 :Ten built as FB-1s from initial order of 16, remaining six modified to other sub-types (FB-2, FB-3, FB-4). Powered by a {{cvt|435|hp}} Curtiss D-12. Initial Navy delivery, shore-based only.

;FB-2 (Model 53) :Two FB-1s modified for carrier operation, {{cvt|510|hp}} Packard 1A-1500 engine. Later converted to FB-1 standard. [[File:Boeing FB-5.jpg|right|thumbnail|A Boeing FB-5 preserved at the [[Steven F. Udvar-Hazy Center]].]]

;FB-3 (Model 55) :Three built to evaluate the {{cvt|510|hp}} Packard 1A-1500 engine. Like the FB-4, the FB-3 was fitted with floatplanes. Following a crash in December 1925, the remaining two were converted to conventional landing gear.

;FB-4 (Model 54) :One built, experimental model with a {{cvt|450|hp}} [[Wright P-1]] radial engine and fitted with floatplanes. Later converted to FB-6 standard.

;FB-5 (Model 67) :27 built, production version. Powered by a {{cvt|520|hp}} Packard 2A-1500 engine.

;FB-6 :FB-4 re-engined with a {{cvt|450|hp}} [[Pratt & Whitney R-1340]]-B Wasp engine.

;FB-7 (Model 67A) :Development of FB-5, powered by a Pratt & Whitney R-1340-A Wasp engine, not built.

;XFB-5 (Model 97) :Designation for one FB-5 (''A-7101'') used for development tests in 1927.

==Operators== ;{{flag|United States|1912}} *[[United States Army Air Corps]] *[[United States Navy]] *[[United States Marine Corps]]

==Aircraft on Display==

'''FB-5'''

[[File:Boeing FB-5 ‘A-7126 - 6-F-11’ (really A-7104) (26552419862).jpg|thumb|right|FB-5 on display at Planes of Fame Air Museum]]

- A-7114 on display at the [[Steven F. Udvar-Hazy Center]], [[Dulles International Airport]], [[Chantilly, Virginia]].

- A-7123 in storage at the [[National Museum of the Marine Corps]], [[Quantico, Virginia]].

- A-7126 on display at [[Planes of Fame Air Museum]], [[Chino, California]].

- Reproduction on display at [[San Diego Air and Space Museum]] Gillespie Field Annex, [[El Cajon, California]].

==Specifications (PW-9)== {{Aircraft specs |prime units?=imp

|ref=Boeing Aircraft since 1916 <ref name="Bowersp84-85">Bowers 1989, pp. 84–85.</ref> |crew=one |length ft=23 |length in=5 |length m= |span ft=32 |span m= |height ft=8 |height in=2 |height m= |wing area sqft=260 |wing area sqm= |airfoil=Göttingen 436 <ref name="Bowersp81">Bowers 1989, p. 81.</ref> |empty weight lb=1,936 |empty weight kg= |gross weight lb=3,120 |gross weight kg= |eng1 name=[[Curtiss D-12]] |eng1 type= water-cooled V-12 |eng1 number=1 |eng1 hp=435 |eng1 kw= |max speed mph=159 |max speed kts= |max speed kmh= |cruise speed mph=142 |cruise speed kts= |cruise speed kmh= |range miles=390 |range nmi= |range km= |ceiling ft=18,925 |ceiling m= |climb rate ftmin=1,630 |climb rate ms= |wing loading lb/sqft=12.0 |wing loading kg/m2=58.7 |power/mass=0.14 hp/lb (0.22 kW/kg) |guns=2 × fixed {{cvt|.30|in|2}} [[machine gun]]s |bombs=1 × {{cvt|244|lb}} bomb }}

==See also== {{Aircontent |related= *[[Boeing XP-8]] *[[Boeing F2B]] |similar aircraft= *[[P-1 Hawk|Curtiss P-1]] *[[Fokker D.XI|Fokker PW-7]] }}

==References==

===Notes=== {{Reflist}}

===Bibliography=== {{Refbegin}} *{{cite book|last=Bowers|first=Peter M.|title=Boeing aircraft since 1916|location=London|publisher=Putnam Aeronautical Books|edition=First|year=1966|ref=Bowers, Boeing aircraft, 1966}} *{{cite book|last=Bowers|first=Peter M.|title=Boeing aircraft since 1916|location=London|publisher=Putnam Aeronautical Books|edition=Second|year=1989|isbn=0-85177-804-6|ref=Bowers, Boeing aircraft, 1989}} *{{cite book|first=Lloyd S.|last=Jones|title=U.S. Naval Fighters|location=Fallbrook, CA|publisher=Aero Publishers|year=1977|pages=35–38|isbn=0-8168-9254-7}} *{{cite book|last1=Swanborough|first1=Gordon|last2=Bowers|first2=Peter M.|title=United States Navy Aircraft since 1911|location=London|publisher=Putnam|edition=Second|year=1976|isbn=0-370-10054-9}} {{Refend}}

==External links== {{commons category|Boeing PW-9/FB}} * {{cite web|first=Joe |last= Baugher |url= http://www.joebaugher.com/usaf_fighters/pw9.html|title=Boeing PW-9|work=Joe Baugher's U.S. Military Aircraft page}} * [https://digitalcollections.museumofflight.org/nodes/view/2804 Instructions for the Assembly and Maintenance of the Boeing Single Seat Pursuit and Fighter Airplanes] – manual for the PW-9 and FB-1/FB-5

{{DEFAULTSORT:Boeing Model 15}} [[Category:1920s United States fighter aircraft]] [[Category:Boeing aircraft|015]] [[Category:Single-engined tractor aircraft]] [[Category:Biplanes]] [[Category:Aircraft first flown in 1923]] [[Category:Aircraft with fixed conventional landing gear]]