Gnome Omega

{{Short description|1900s French aircraft piston engine}}  {{infobox aero engine |name= Omega |image =File:Gnome Omega Newark Air Museum.jpg |caption = Gnome 7 Omega on display at the [[Newark Air Museum]] |engine_type= [[Rotary engine|Rotary]] [[Aircraft engine|aero engine]] |national_origin = |manufacturer= [[Société des Moteurs Gnome]] |first_run=1908 |major_applications={{ubl | [[Blériot XI]] | [[Bristol Boxkite]] }} |number_built = 4,000 until 1914<ref name = Nahum>{{harvnb|Nahum|1999|pp=12–14}}</ref> |developed_from = |developed_into = |variants_with_their_own_articles = }}

The '''Gnome 7 Omega''' (commonly called the '''Gnome 50 hp''') is a French seven-cylinder, [[air-cooled]] [[Aircraft engine|aero engine]] produced by [[Gnome et Rhône]].<ref name=si>{{harvnb|Smithsonian Institution|2018}}</ref> It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's first<ref name=Nahum/> aviation [[rotary engine]] produced in quantity. Its introduction revolutionized the aviation industry<ref name=Murphy>{{harvnb|Murphy|2005}}</ref> and it was used by many early aircraft. It produced {{cvt|50|hp|disp=flip}} from its {{cvt|8|L|cuin}} engine [[Engine displacement|capacity]].<ref name="Lumsden">{{harvnb|Lumsden|2003|p=152}}</ref> A Gnome Omega engine powers the 1912 [[Blackburn Type D|Blackburn Monoplane]], owned and operated by the [[Shuttleworth Collection]], the oldest known airworthy British-designed aeroplane worldwide.<ref>{{harvnb|Shuttleworth|2018}}</ref> A two-row version of the same engine was also produced, known as the '''Gnome 14 Omega-Omega''' or '''Gnome 100 hp'''. The prototype Omega engine still exists, and is on display at the United States' [[National Air and Space Museum]].<ref name=si/>

Like all early Gnome et Rhône engines the Omega features a single pushrod driven exhaust valve on the cylinder head; the intake valve is located in the piston crown, opening by inertia on the downstroke and feeding the intake charge from the crankcase into the upper part of the cylinder. No throttle is provided, the pilot controls the aircraft's speed by switching off the ignition when necessary. [[File:Gnome-GA section.png|thumb|350px|sectional views of the Gnome Omega]]

==Variants== ;Gnome 7 Omega:Single-row 7-cyl. original version; {{convert|50|hp|kW|abbr=on|0}}. ;Gnome 14 Omega-Omega :Two-row, 14-cylinder version using Omega [[Cylinder (engine)|cylinders]]; {{convert|100|hp|kW|abbr=on|0}}.

==Applications==

===Gnome 7 Omega=== [[File:Blackburn Type D image0.JPG|thumb|right|Gnome Omega-powered airworthy [[Blackburn Type D|Blackburn Monoplane]] of the [[Shuttleworth Collection]]]] {{columns-list|colwidth=24em| *[[A Vlaicu I]] *[[A Vlaicu II]] *[[ASL Valkyrie]] *[[Avro Type 500]] *[[Avro-Burga Monoplane]] *[[Blackburn Mercury]] *[[Blackburn Type D Monoplane]] *[[Blériot XI]] *[[Breguet Type III]] *[[Breguet Type IV]] *[[Bristol Boxkite]] *[[Bristol Racing Biplane]] *[[Bristol Monoplane]] *[[Bristol-Prier P.1]] *[[Bristol-Coanda School Monoplane]] *[[Bristol-Coanda T.B.8]] *[[Castaibert III]]<ref>{{harvnb|Schiere|1969|pp=15–16}}</ref> *[[Caudron Type B]] *[[Deperdussin 1910 monoplane]] *[[François Denhaut]]'s flying boat *[[Fabre Hydravion]] *[[Farman HF.6 Militaire]] *[[Farman III]] *[[FBA Type A]] *[[Grahame-White Type VII]] *[[Grahame-White Type XV]] *[[Howard Wright 1910 Biplane]] *[[Koolhoven Heidevogel]] *[[Lakes Waterbird]] *[[London and Provincial Fuselage Biplane]] *[[Morane-Borel monoplane]] *[[Nieuport II]] *[[Paalson Type 1]] *[[Paulhan-Tatin Aéro-Torpille No.1]] *[[Paulhan biplane]] *[[Pemberton-Billing P.B.9]] *[[Porter Gyropachute]] *[[Radley-England waterplanes]] *[[Royal Aircraft Factory B.E.3]] *[[Royal Aircraft Factory B.E.4]] *[[Royal Aircraft Factory F.E.2]] *[[Sommer 1910 biplane]] *[[Short S.27]] *[[Short Tandem Twin]] *[[Short Triple Twin]] *[[Short S.47 Triple Tractor]] *[[Short S.62]] *[[Sopwith Bee]] *[[Sopwith Sparrow]] *[[Van Meel Brikken]] *[[Vickers No.6 Monoplane]] *[[Vickers No.7 Monoplane]] *[[Vickers Boxkite School Biplane]] *[[Voisin 1907 biplane]] *[[Voisin Type de Course]] *[[Voisin L]] }}

[[File:Gnome Omega-Omega - Moteurs Gnome October 1913.png|thumb|Gnome 14 Omega-Omega, as shown in a 1913 Gnome catalog.]]

===Gnome 14 Omega-Omega=== *[[Avro 501]] *[[Blériot XIII]] *[[Bleriot XXIII]] *[[Bristol-Gordon England G.E.2]] *[[Coventry Ordnance Works Biplane 10]] *[[Deperdussin 1912 Racing Monoplane]] *[[Nieuport IV|Nieuport IV.H]] floatplane *[[Short S.41 Tractor Biplane]] *[[Short S.57|Short S.57 Seaplane]] *[[Short S.64|Short S.64 Folder Seaplane]] *[[Short Admiralty Type 74]]

==Engines on display== *The very first Gnome rotary engine ever built, Gnôme Omega No. 1, is on display at the [[National Air and Space Museum]], [[Washington, D.C.]]<ref name=si/> *A preserved production Gnome 7 Omega engine is on public display at the [[Royal Air Force Museum London]]. *A restored Omega is on display at the [[New England Air Museum]], Windsor Locks, CT.<ref>{{harvnb|Hurley|2018}}</ref>

==Specifications (7 Omega)== [[File:Gnome Omega OW.jpg|thumb|right|Brown staining of the Shuttleworth example caused by burnt [[castor oil]]]] {{pistonspecs|   |ref=''Lumsden''.<ref name="Lumsden"/> |type=7-cylinder, single-row, [[rotary engine]] |bore= {{convert|110|mm|in|abbr=on}} |stroke= {{convert|120|mm|in|abbr=on}} |displacement= {{convert|8|L|cuin|1|abbr=on}} |length= {{convert|79|cm|in|abbr=on}} |diameter= {{convert|84|cm|in|abbr=on}} |width= |height= |weight= {{convert|75|kg|lb|abbr=on}} |valvetrain=pressure-driven inlet valves are located on the pistons<ref name=Nahum/> |supercharger= |turbocharger= |fuelsystem= |fueltype= |oilsystem=[[Total-loss oiling system|Total loss]], [[castor oil]] |coolingsystem=Air-cooled |power= {{convert|37|kW|hp|abbr=on}} at 1,200 rpm |specpower= |compression= |fuelcon= |specfuelcon= |oilcon= |power/weight= |reduction_gear=Direct drive, right-hand tractor, left-hand pusher }}

==See also== {{aircontent  |see also=

|related=

|similar aircraft=

|lists= *[[List of aircraft engines]]

|similar engines= *[[Clerget 7Z]] *[[Le Rhône Type 7A]] *[[Le Rhône Type 7B]] *[[Le Rhône Type 7B2]]  }}

==Footnotes==

===References=== * {{cite web | url = https://www.neam.org/engine-collection-detail.php?name=gnome7omega | title = Gnome 7 Omega | access-date = Aug 17, 2018 | last = Hurley | first = Nick | year = 2018 | website = New England Air Museum | archive-url = https://web.archive.org/web/20180818052459/https://www.neam.org/engine-collection-detail.php?name=gnome7omega | url-status = dead | archive-date = August 18, 2018 }} * {{cite book | last1 = Lumsden | first1 = Alec | title = British Piston Engines and their Aircraft | year = 2003 | publisher = Airlife Publishing | location = Marlborough, Wiltshire, UK | isbn = 1853102946 }} * {{cite book|last=Murphy|first=Justin D.|title=Military aircraft, origins to 1918: an illustrated history of their impact|year=2005|publisher=ABC-CLIO|location=Santa Barbara, Calif. [u.a.]|isbn=1-85109-488-1|pages=32–33|url=https://books.google.com/books?id=7pS1QpH8FRgC&q=first%20rotary%20engine%201908%20Omega&pg=PA32}} * {{cite book|last=Nahum|first=Andrew|title=The rotary aero engine|year=1999|publisher=Science Museum|location=London, UK|isbn=1-900747-12-X|pages=12–14|url=https://books.google.com/books?id=gRzsTSKAlDAC&q=first%20rotary%20engine%201908&pg=PA13}} * {{cite book | last1 = Schiere | first1 = J | editor1-first = Fred T. | editor1-last = Jane | editor1-link = Fred T. Jane | title = Jane's All the World's Aircraft | url = https://www.gutenberg.org/files/34815/34815-h/34815-h.htm#Page_15 | access-date = Aug 17, 2018 | volume = 1913 | year = 1969 | orig-year = 1913 | publisher = Arco Publishing Company Inc. | location = New York, NY | chapter = Aeroplanes & Dirigibles: Argentine | lccn = 69-14964 }} * {{cite web| url=https://airandspace.si.edu/collection-objects/gnome-omega-no-1-rotary-engine| title=Gnome Omega No. 1 Rotary Engine | access-date= Aug 17, 2018 | author=Smithsonian Institution | year= 2018| work=National Air and Space Museum | publisher=Smithsonian Institution | location= Washington, DC| archive-url=https://web.archive.org/web/20180710071227/https://airandspace.si.edu/collection-objects/gnome-omega-no-1-rotary-engine | url-status=dead| archive-date = July 10, 2018 }} * {{cite web| url= http://www.shuttleworth.org/collection/blackburnmonoplane/ | title = Blackburn Monoplane | access-date = Aug 17, 2018 | author= Shuttleworth | year = 2018 | website = Shuttleworth Collection | archive-url = https://web.archive.org/web/20180819104123/http://www.shuttleworth.org/collection/blackburnmonoplane/ | url-status= dead | archive-date = August 19, 2018 }}

==Further reading== *{{cite book|title=Moteurs d'Aviation Gnome|date=1910|publisher=Société Des Moteurs Gnome|location=Paris|url=https://www.museesafran.com/sites/musee/files/journaux/17-livres_espace_patrimoine_moteurs_aviation_gnome.pdf|access-date=19 June 2018|language=fr}}

==External links== {{Commons category multi|Gnome Omega|Gnome Omega-Omega}} * [https://airandspace.si.edu/collection-objects/gnome-omega-no-1-rotary-engine/nasm_A19990069000 NASM's page on Gnome Omega No.1] * [https://www.youtube.com/watch?v=RaWwgQDrGMw Video of April 2009 ground runup of a restored Gnome Omega in the USA]

[[Category:Gnome-Rhône aircraft engines|Omega]] [[Category:Air-cooled aircraft piston engines]] [[Category:1900s aircraft piston engines]] [[Category:Rotary aircraft piston engines]] [[Category:Seven-cylinder engines]]