Wibault 12 Sirocco

{{Infobox aircraft | name = Wib 12 Sirocco | logo = | logo_size = | image = VickersW127.jpg | alt = | caption = Wib 122 (Vickers 127) | long_caption = | other_names = | aircraft_type = Two seat fighter aircraft | aim = | outcome = | related = | national_origin = France | manufacturer = Avions Michel Wibault | design_group = | designer = Michel Wibault | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = 3 | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = May 1926 | initiated = | in_service = | last_flight = | expected = | developed_from = Wibault 8 Simoun | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''Wibault 12 Sirocco''' or '''Wib 12 Sirocco''' was a two-seat, parasol wing fighter aircraft designed and built in France in the 1920s. Three fighter prototypes were completed, one for the RAF and two Army co-operation variants. There was no series production.

==Design== The Wib 12 Sirocco, a single engine, two seat, parasol wing fighter was a structurally much revised development of the similarly configured Wib 8 Simoun, following it through the Avions Marcel Wibault works with less than a month between their maiden flights. They were externally very similar but the more refined structure of the Wib 12 made it both stronger and 12% lighter than its predecessor. One major change was the replacement of the Wib 8's box spars with ones of I-section.<ref name=G&S/>

The general design followed that of Wibault's family of single- and two-seat fighters, the Wib 3, Wib 7, Wib 8 and Wib 9 but in external detail was closest to the Wib 8. It was an all-metal aircraft, the structure mostly Duralumin and covered with narrow aluminium strips applied longitudinally. The parasol wing was straight edged and of constant chord, braced to the lower fuselage with a pair of parallel struts on each side which met the wing at about mid-span. The Wib 12 had a new pair of jury struts from the main wing struts to the wing underside for strengthening. There were cabane struts over the fuselage and a trailing edge cut-out in the wing over the pilot's cockpit to enhance his visibility. A pair of synchronised {{Convert|7.7|mm|in|3|abbr=on}} Vickers machine guns fixed to the fuselage fired forwards through the propeller arc; in addition the rear cockpit was fitted with a pair of Lewis guns of the same calibre on a Scarff ring. A braced tailplane was mounted towards the top of the fuselage, together with an angular fin and rudder.<ref name=G&S/>

The Wib 12's engine, the same {{convert|500|hp|kW|abbr=on|0}} water-cooled V-12 Hispano-Suiza 12Hb type as used by the Wib 8, was totally enclosed and drove a two blade propeller. It was cooled by a retractable, half-cylindrical radiator on the fuselage underside at the back of the engine. Behind the engine the fuselage was flat sided. The fighter had a fixed conventional undercarriage with mainwheels on a split axle attached to the fuselage underside, supported by a pair of V-struts; there was a small tailskid.<ref name=G&S/>

The Wib 12 and the '''Wib 121''' (the first and second prototypes) were both flown for the first time in May 1926. The latter was about 8% faster in a climb to 4,000 m (13,125 ft) than the heavier Wib 8.<ref name=G&S/> The third aircraft, the '''Wib 122''' was built for Vickers aircraft, with whom Wibault shared patents and collaborative designs. They fitted it with a {{convert|550|hp|kW|abbr=on|0|disp=flip}} W-12 Napier Lion XI engine and knew it as the '''Vickers Type 127'''. To avoid the central bank of cylinders the Vickers guns were moved from the fuselage top to the sides. Its test programme was interrupted by continual engine overheating problems.<ref name=G&S/><ref name=A&M/>

When the Service Technique de l'Aéronautique (S.T.Aé, Technical Department of Aeronautics) cancelled the two seat fight specification in 1926, further development by Wibault also ended; though the Wib 121 went on a sales demonstration in Turkey in 1928, no orders were gained.<ref name=G&S/> Instead, the company tried to develop the design into a two-seat Army cooperation reconnaissance aircraft. The '''Wib 124''' had its armament modified, having no wing guns and only one fuselage mounted synchronised Vickers machine gun, but with an added ventral Lewis gun.<ref name=AF_124/> The '''Wib 125''' had the same armament but was powered by a Renault 12Jc {{convert|500|hp|kW|abbr=on|0}} water-cooled V-12 engine. Again, no orders resulted.<ref name=AF_125/>

==Variants== thumb|Wibault 12 photo from L'Aéronautique October,1927 C=Chasseur (fighter); A=Army; 2=two-seater. One of each only. ;Wib 12 Sirocco C.2: First prototype, fuselage and rear seat guns only.<ref name=G&S/> ;Wib 121 Sirocco C.2: Second prototype, wing guns added. ;Wib 122 Sirocco C.2: One aircraft built as the '''Vickers Type 127'''. ;Wib 124 A.2: Army co-operation version. No wing guns and only one synchronised Vickers gun in upper fuselage but a ventral Lewis gun added.<ref name=AF_124/> ;Wib 125 A.2: Army co-operation version. Renault 12Jc {{convert|500|hp|kW|abbr=on|0}} water-cooled V-12 engine, same armament as Wib 124.<ref name=AF_125/> ;Vickers Type 127 :\the single Wib 122 Sirocco C.2 built for Vickers, who replaced the Hispano engine with a {{convert|550|hp|kW|abbr=on|0|disp=flip}} W-12 Napier Lion XI. Vickers referred to it as the '''Vickers Type 127'''; its RAF serial was ''J9029''.<ref name=G&S/><ref name=A&M/>

==Specifications (Wib 121 C.2)== {{Aircraft specs |ref=The Complete Book of Fighters,<ref name=G&S/> Jane's all the World's Aircraft 1928<ref name=JAWA1928/> |prime units?=met  |crew=One |capacity= |length m=9.44 |length note= ('''122 C.2''' {{cvt|9.09|m}}) |span m=12.66 |span note= |height m=3.15 |height note= |wing area sqm=29.63 |wing area note= |aspect ratio= |airfoil= |empty weight kg=1212 |empty weight note= ('''122 C.2''' {{cvt|1234|kg}}) |gross weight kg=2050 |gross weight note=('''122 C.2''' {{cvt|2085|m}}) |max takeoff weight kg= |max takeoff weight lb= |max takeoff weight note= |fuel capacity= |more general=  |eng1 number=1 |eng1 name=Hispano-Suiza 12Hb |eng1 type=water-cooled upright V-12 |eng1 hp=500 |eng1 note=('''122 C.2''' {{cvt|550|hp|order=flip}} Napier Lion XI W-12) |more power=

|max speed kmh=242 |max speed note=at 3,000 m (9,840 ft) |cruise speed kmh= |cruise speed mph= |cruise speed kts= |cruise speed note= |stall speed kmh= |stall speed mph= |stall speed kts= |stall speed note= |never exceed speed kmh= |never exceed speed mph= |never exceed speed kts= |never exceed speed note= |range km= |range note= |combat range km= |combat range miles= |combat range nmi= |combat range note= |ferry range km= |ferry range miles= |ferry range nmi= |ferry range note= |endurance= |ceiling m=6200 |ceiling note= |g limits= |roll rate= |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude=14.15 min 33 s to 4,000 m (13,125 ft) |wing loading kg/m2=70.5 |wing loading note=('''122 C.2''' {{cvt|70.5|kg/m2}}) |power/mass= '''122 C.2''' {{cvt|0.119|hp/lb|kW/kg|order=flip}} with {{cvt|550|hp|order=flip}} Napier Lion XI  |armament= *'''Wing guns:''' 2×{{Convert|7.7|mm|in|3|abbr=on}} unsynchronised Darne machine guns firing outside the propeller arc. *'''Fuselage guns''' 2×{{Convert|7.7|mm|in|3|abbr=on}} synchronised Vickers machine guns firing through the propeller arc. *'''Rear cockpit:''' 2×{{Convert|7.7|mm|in|3|abbr=on}} Lewis machine guns on a Scarff ring. }}

==References== {{commons category|Wibault 12 Sirocco}} <references> *<ref name=JAWA1928>{{cite book |title=Jane's all the World's Aircraft 1928 |editor1-last=Grey |editor1-first=C.G. |year=1928 |publisher=Sampson Low, Marston & company, ltd |location=London |pages=124c-125c}}</ref> *<ref name=G&S>{{cite book |last=Green |first=William |first2= Gordon|last2= Swanborough |title=The Complete Book of Fighters |year=1994|publisher=Salamander Books|location=Godalming, UK|isbn=1-85833-777-1|pages=596–7}}</ref> *<ref name=A&M>{{cite book |title= Vickers Aircraft since 1908 |last= Andrews |first= CF |last2=Morgan|first2=E.B. |edition= 2nd |year= 1988|publisher= Putnam|location= London|isbn= 0 85177 815 1|pages=209, 515}}</ref> *<ref name=AF_124>{{cite web |url=http://www.aviafrance.com/wibault-124-aviation-france-9391.htm |title=Wibault 124|access-date=1 May 2013}}</ref>

*<ref name=AF_125>{{cite web |url=http://www.aviafrance.com/wibault-125-aviation-france-2339.htm |title=Wibault 125|access-date=1 May 2013}}</ref> </references>   {{Wibault aircraft}}

Category:Parasol-wing aircraft Category:1920s French fighter aircraft Wib 12 Category:Single-engined tractor aircraft