{{Short description|French single engine plane}} <!-- This article is a part of Wikipedia:WikiProject Aircraft. Please see Wikipedia:WikiProject Aircraft/page content for recommended layout. --> {{Infobox aircraft | name = Leduc RL.21 | logo = | logo_size = | image = Leduc RL.21 1967.png | alt = | caption = RL.21 with (from left) Prosper (engineer), R. Leduc (designer) and R. Davy (pilot) | long_caption = | other_names = | aircraft_type = Class speed record setter | aim = | outcome = | related = | national_origin = France | manufacturer = | design_group = | designer = René Leduc | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = 1 | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = August 1960 | initiated = | in_service = | last_flight = | expected = | developed_from = | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}
The '''Leduc RL.21''' was a single engine, single seat light aircraft built in the late 1950s in France. Designed to achieve high speeds from modest engine power, it set seven class records in the early 1960s.
==Design and development== Between 1939 and 1975 the amateur aircraft designer and builder René Leduc (not the ramjet designer of the same name){{citation needed|date=April 2018}} completed and flew five different lightplanes, two of which set records in their class.<ref name=af/><ref name=Flight60/><ref name=Flight67/> The RL.21 was a low wing monoplane with its wings braced to the upper fuselage by a pair of inverted-V struts. It was powered by a {{convert|135|hp|kW|abbr=on|order=flip|0}} SNECMA-Régnier 4L-00 four cylinder inverted air-cooled inline engine driving a two blade propeller. A low, smoothly streamlined canopy covered the single seat cockpit and merged aft into a raised rear fuselage. The empennage was conventional. The RL.21 had a tailwheel undercarriage with spatted main wheels on cantilever legs, mounted on the wings approximately below the ends of the wing struts.<ref name=GaillardI/>
Leduc built the RL.21 over a period of six years with assistance from Sud Aviation and from the Nantes Technical School. It flew for the first time in August 1960.<ref name=GaillardI/> Between late 1960 and early 1967 it set seven records in its C1a and C1b categories,<ref name=Flight67/> respectively for aircraft with maximum take-off weights below {{convert|500|kg|lbs|abbr=on|0}} and between {{convert|500-1000|kg|lbs|abbr=on|0}}.<ref name=Flight60/> The earliest were for speeds of {{convert|313.5|km/h|mph|abbr=on|1|}} and {{convert|316.2|km/h|mph|abbr=on|1|}} for the two classes around a {{convert|100|km|mi|abbr=on|0}} closed circuit <ref name=Flight60/> and the last at {{convert|217|mph|km/h|abbr=on|1|order=flip}} and {{convert|208|mph|km/h|abbr=on|1|order=flip}} over a {{convert|500|km|mi|abbr=on|0}} closed circuit.<ref name=Flight67/> Throughout these flights the pilot was Raymond Davy.<ref name=GaillardI/>
==Specifications== {{Aircraft specs |ref=Gaillard (1990) p.209<ref name=GaillardI/> |prime units?=met <!-- General characteristics --> |genhide=
|capacity=One |length m=6.90 |length note= |span m=5.70 |span note= |height m= |height ft= |height in= |height note= |wing area sqm=6.5 |wing area note= |aspect ratio=<!-- sailplanes --> |airfoil= |empty weight kg=390 |empty weight note= |gross weight kg= |gross weight lb= |gross weight note= |max takeoff weight kg=500 |max takeoff weight note= |fuel capacity= |more general= <!-- Powerplant --> |eng1 number=1 |eng1 name=SNECMA-Régnier 4L-00 |eng1 type=4 cylinder inverted air-cooled inline |eng1 hp=135 |eng1 note= |power original= |more power=
|prop blade number=2 |prop name= |prop dia m=<!-- propeller aircraft --> |prop dia ft=<!-- propeller aircraft --> |prop dia in=<!-- propeller aircraft --> |prop dia note=
<!-- Performance --> |perfhide=
|max speed kmh=360 |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= |minimum control speed kmh= |minimum control speed mph= |minimum control speed kts= |minimum control speed note= |range km= |range miles= |range nmi= |range note= |endurance=<!-- if range unknown --> |ceiling m=8000 |ceiling note= |g limits=<!-- aerobatic --> |roll rate=<!-- aerobatic --> |glide ratio=<!-- sailplanes --> |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |sink rate ms=<!-- sailplanes --> |sink rate ftmin=<!-- sailplanes --> |sink rate note= |lift to drag= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |fuel consumption kg/km= |fuel consumption lb/mi= |power/mass=
|more performance=
}}
==References== <references>
<ref name=GaillardI>{{cite book |title=Les Avions Francais de 1944 à 1964|last=Gaillard|first=Pierre|year=1990|publisher=Éditions EPA|location=Paris|isbn=2 85120 350 9|page=209}}</ref>
<ref name=Flight60>{{cite magazine |date=9 December 1960 |title= Sport and Business|magazine= Flight|volume=78 |issue=2700 |page=700 |url= http://www.flightglobal.com/pdfarchive/view/1960/1960%20-%202894.html}}</ref>
<ref name=Flight67>{{cite magazine |date=12 January 1967|title=Sport and Business|magazine= Flight|volume=91 |issue=3018 |page=52 |url=http://www.flightglobal.com/pdfarchive/view/1967/1967%20-%200054.html}}</ref>
<ref name=af>{{cite web |url=http://www.aviafrance.com/aviafrance1.php?ID=9884&ID_CONSTRUCTEUR=1475&ANNEE=0&ID_MISSION=0&MOTCLEF=|title=Leduc R-21 |accessdate=20 January 2015}}</ref>
</references> <!-- ==Further reading== --> <!-- ==External links== -->
{{Leduc aircraft}}
Category:1960s French sport aircraft RL.21 Category:Single-engined tractor aircraft Category:Low-wing aircraft Category:Aircraft first flown in 1960