View source for Farman HF.20

{{short description|French WW1 reconnaissance aircraft}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{|{{Infobox aircraft begin
 |name=HF.20
 |image=Henry Farman Biplane - Jul 1912.jpg
 |caption=
}}{{Infobox aircraft type
 |type=Reconnaissance aircraft
 |manufacturer=[[Farman Aviation Works|Farman]]
 |designer=[[Henri Farman]]
 |first flight={{avyear|1913}}
 |introduced=
 |retired=
 |status=
 |primary user=
 |more users=
 |produced=
 |number built=
 |variants with their own articles=
}}
|}
[[File:IAN 2332.jpg|thumb|An HF.20 biplane at Nicopolis airfield, near [[Preveza]], in December 1912]]
The '''Farman HF.20''' and its derivatives were a family of reconnaissance aircraft produced in France shortly before and during the [[First World War]]. It was a refined version of the [[Farman MF.11]] "Shorthorn" that did away with the type's distinctive landing skids, and incorporated design features from [[Henri Farman]]'s designs. It entered service with the French, Belgian and Serbian armies in 1913 (two aircraft conducted reconnaissance during the [[Siege of Scutari|Siege of Shkodër]] in the [[First Balkan War]] and one crashed), and with the British [[Royal Flying Corps|RFC]] and [[RNAS]] shortly after the outbreak of war. The type was also licence-built in the UK by [[Airco]] and [[Grahame-White]].

The HF.20 was seriously underpowered, and a variety of engines were trialled in the hope of correcting this, none with much success. The problem was eventually solved only when an engine of twice the power of the original powerplant was fitted to the '''HF.27''' variant, by which time the aircraft was already obsolete. Nevertheless, the performance of the HF.20 made it adequate for use on secondary fronts.
<!-- ==Development== -->
<!-- ==Operational history== -->

==Variants==
;HF.20: original version with [[Gnome Lambda]] engine <!-- what type?? -->
;HF.21: {{cvt|15.5|m}} span and increased wing area version with [[Gnome Lambda]] engine. At least one of the few built, entered service with the [[Fliegertruppe]] of Switzerland.
;HF.22: {{cvt|15.58|m}} span and increased wing area version with Gnome Lambda engine. 
;HF.22 floatplane: (aka '''HF.22bis''' or Savoia-built '''HF.22-H''')
;HF.23: {{cvt|18.08|m}} span version with Gnome Lambda engine
;HF.24: {{cvt|11.5|m}} span aerobatic version with Gnome Lambda engine
;HF.27: {{cvt|155|hp}} [[Canton-Unné R9]] engine or {{cvt|240|hp}} [[Renault]] engine with a revised undercarriage that included nose wheels similar to the [[Voisin III]].

==Operators==
[[File:Ein einsitziger Doppeldecker vor dem Start - CH-BAR - 3240087.tif|thumb|HF-20 of the Swiss Air Force during the First World War]]
;{{ARG}}
*[[Argentine Air Force]]
;{{BEL}}
*[[Belgian Air Force]]
;{{DEN}}
*[[Royal Danish Air Force]]
;{{FRA}}
*[[Aéronautique Militaire]]
:[[Escadrille HF 1]]
:[[Escadrille HF 7]]
:[[Escadrille HF 13]]
:[[Escadrille HF 19]]
:[[Escadrille HF 28]]
:[[Escadrille HF 32]]
;{{flag|Greece|old}}
*[[Royal Hellenic Navy]]
;{{flag|Kingdom of Italy}}
*[[Corpo Aeronautico Militare]]
;{{JPN}}
*[[Imperial Japanese Navy Air Service]]
;{{flag|Netherlands}}
*[[Royal Netherlands Air Force]]
;{{ROM}}
*[[Royal Romanian Air Force]]
;{{RUS}}
*[[Imperial Russian Air Service]]
;{{flag|Serbia}}
*[[Serbian Air Force]]
;{{USSR}}
*[[Soviet Air Force]] - Taken over from the Imperial Russian Air Force.
;{{SWE}}
*[[Swedish Air Force]]
*[[Swedish Navy]]
;{{flag|Switzerland}}
*[[Swiss Air Force]]
;{{UK}}
*[[Royal Flying Corps]]
**[[No. 2 Squadron RAF|No. 2 Squadron RFC]]
**[[No. 5 Squadron RAF|No. 5 Squadron RFC]]
**[[No. 6 Squadron RAF|No. 6 Squadron RFC]]
**[[No. 10 Squadron RAF|No. 10 Squadron RFC]]
**[[No. 24 Squadron RAF|No. 24 Squadron RFC]]
**[[No. 26 Squadron RAF|No. 26 Squadron RFC]]
**[[No. 30 Squadron RAF|No. 30 Squadron RFC]]
**[[No. 31 Squadron RAF|No. 31 Squadron RFC]]
**[[No. 32 Squadron RAF|No. 32 Squadron RFC]]
**[[No. 64 Squadron RAF|No. 64 Squadron RFC]]
*[[Royal Naval Air Service]]
;{{flagicon| South Africa|1910}} '''[[South Africa|Union of South Africa]]'''
*[[South African Air Force|South African Aviation Corps]]
<!-- ==Units using this aircraft/Operators (choose)== -->

==Specifications (HF.20)==
{{Aircraft specs
|ref=French aircraft of the First World War<ref name="Davilla">{{cite book |last1=Davilla |first1=Dr. James J. |last2=Soltan |first2=Arthur M. |title=French aircraft of the First World War |date=January 2002 |publisher=Flying Machines Press |isbn=1891268090 |pages=207–212}}</ref>
|prime units?=met
<!--
        General characteristics
-->
|crew=2 (pilot and observer)
|length m=8.06
|span m=13.65
|height m=3.15
|wing area sqm=35
|aspect ratio=<!-- sailplanes -->
|airfoil=
|empty weight kg=360
|gross weight kg=660
|max takeoff weight kg=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name=[[Gnome Lambda]]
|eng1 type=7-cylinder air-cooled rotary piston engine
|eng1 hp=80

|prop blade number=2
|prop name=fixed-pitch wooden pusher propeller
|prop dia m=<!-- propeller aircraft -->
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed kmh=165
|max speed mph=
|max speed kts=
|max speed note=
|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=315
|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=3 hours
|ceiling m=1050
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ms=
|climb rate ftmin=
|climb rate note=
|time to altitude={{cvt|2000|m}} in 22 minutes
|wing loading kg/m2=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption kg/km=
|fuel consumption lb/mi=
|power/mass=
|more performance=
<!--
        Armament
-->

|guns= 1 × machine gun on flexible mount for observer
|bombs= small load of {{cvt|75|mm}} bombs
}}

==References==
{{commons category|Farman HF.20}}
{{reflist}}

==Bibliography==
*{{cite journal |last1=Klaauw|first1=Bart van der|title=Unexpected Windfalls: Accidentally or Deliberately, More than 100 Aircraft 'arrived' in Dutch Territory During the Great War |journal=Air Enthusiast |date=March–April 1999 |issue=80 |pages=54–59 |issn=0143-5450}}
*{{cite book |last1=Liron |first1=Jean |title=Les avions Farman |year=1984 |publisher=Éditions Larivière |location=Paris |oclc=37146471|series=Collection Docavia|volume=21}}
* Thomas, Andrew. "In the Footsteps of Daedulus: Early Greek Naval Aviation". ''Air Enthusiast'', No. 94, July–August 2001, pp.&nbsp;8–9. {{ISSN|0143-5450}}

==Further reading==
* {{cite book |last= Taylor |first= Michael J. H. |title=Jane's Encyclopedia of Aviation |year=1989 |publisher=Studio Editions |location=London |pages=380–381 }}
* {{cite book |title=World Aircraft Information Files |publisher=Bright Star Publishing|location=London |pages=File 894 Sheet 14–15 }}
<!-- ==External links== -->

{{Farman aircraft}}
{{Dux aircraft}}

[[Category:1910s French military reconnaissance aircraft]]
[[Category:Farman aircraft|HF.20]]
[[Category:Single-engined pusher aircraft]]
[[Category:1910s French military trainer aircraft]]
[[Category:Sesquiplanes]]
[[Category:Aircraft first flown in 1913]]
[[Category:Rotary-engined aircraft]]