- Design and development
- Specifications (X-113 Am)
- Video
- References
| name=RFB X-113 | image=RFB X.113AM Aerofoilboot D-9568 LBG 02.06.73 edited-2.jpg | caption=The RFB X-113 Aerofoil Boat exhibited at the 1973 Paris Air Show at Le Bourget Airport }}{{Infobox Aircraft Type | type=Ground effect vehicle | national origin=Germany | manufacturer=Rhein Flugzeugbau (RFB) | designer=Alexander Lippisch | first flight=October 1970 | introduced= | retired= | status= | primary user= | more users= | produced= | number built=1 | program cost= | unit cost= | developed from= Collins X-112 | developed into= RFB X-114 | variants with their own articles=
}} |
The RFB X-113 Aerofoil Boat was an experimental ground effect vehicle intended to work over water. It was one of three such aircraft designed by Alexander Lippisch in the 1960s and early 1970s. The X-113 first flew in 1970; only one was built. Design and developmentLippisch's development of his Aerofoil Boat, a ground effect vehicle for use over water, began whilst he was working in the aviation division of the Collins Radio Company in Cedar Rapids, Iowa, US. The first test of concept was the Collins X-112, flown in the mid-1960s. In 1967 development was continued in collaboration with Rhein-Flugzeugbau (RFB) in Germany, funded by the German government. This resulted in the X-113. The X-113 was an inverse delta aircraft; that is, it had a wing which was triangular in plan but with a straight, unswept leading edge.[ Combined with strong anhedral, this layout produces stable flight in ground effect.[3] Specifically, it is claimed that it is stable in pitch and also that it can fly in ground effect at altitudes up to about 50% of its span, allowing it to operate over rough water. This contrasts with the lower aspect ratio square wing of the Ekranoplans which leaves ground effect at only 10% of span, limiting them to the calmer waters of lakes and rivers.[4]] The Aerofoil Boat was built using glassfibre sandwiches with foam or tube cores. Its wing was set high on the fuselage, with swept fins at the tips inclined at about 60°, carrying short ailerons. The tips also carried long, wide planing floats which projected a long way forward of the leading edge to support the fuselage stably above the surface when on water. Forward of the wings the fuselage was flat sided and quite shallow, so the pilot was semi-recumbent under a long canopy. Aft, a long dorsal fin extends to a T tail with rudder and horizontal stabiliser. The Aerofoil Boat was powered by a Nelson flat four engine derated to {{convert|40|hp|kW|abbr=on|0|disp=flip}}, driving a two blade, wooden, tractor propeller. The engine was mounted uncowled over the fuselage near mid-chord on a pylon constructed from three pairs of narrow angle V-struts. The first flight was made in October 1970 on Lake Constance and the initial tests to explore the performance of the Aerofoil Boat were also done there. These were deemed satisfactory and later flights over the North Sea showed that it could be operated over rough water. It also demonstrated its ability to fly out of ground effect, reaching at least {{convert|1500|ft|m|abbr=on|0|disp=flip}}.[7] Flight tests continued at least until 1974 and possibly later. The X-113 was displayed in public at the Paris Salon in May 1973. Specifications (X-113 Am) {{Aircraft specs
|ref=Jane's All the World's Aircraft 1974/5
|prime units?=met
|genhide=
|crew=One
|capacity=
|length m=8.43
|length note=
|span m=5.89
|span note=
|height m=2.07
|height note=
|wing area sqm=
|wing area sqft=
|wing area note=
|aspect ratio=
|airfoil=
|empty weight kg=255
|empty weight note=
|gross weight kg=345
|gross weight note=
|max takeoff weight kg=
|max takeoff weight lb=
|max takeoff weight note=
|fuel capacity=
|more general=
|eng1 number=1
|eng1 name=Nelson H63-CP
|eng1 type=flat four
|eng1 hp=40
|eng1 note=derated from {{convert|48|hp|kW|abbr=on|0|disp=flip}}
|power original=
|more power=
|prop blade number=2
|prop name=
|prop dia m=1.17
|prop dia note=wooden, tractor
|perfhide=
|max speed kmh=
|max speed mph=
|max speed kts=
|max speed note=
|cruise speed kmh=80
|cruise speed note=[10]
|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=
|ceiling ft=1500
|ceiling note=out of ground effect, at least[7]
|g limits=
|roll rate=
|glide ratio=
|climb rate ms=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|sink rate ms=
|sink rate ftmin=
|sink rate note=
|lift to drag=
|wing loading kg/m2
|wing loading lb/sqft=
|wing loading note=
|power/mass=
|more performance=
- Take-off speed: {{convert|40|km/h|mph|abbr=on|0}}[10]
- Efficient cruise height: {{convert|175|mm|in|abbr=on|0}}[13]
- Ground effect limit: {{convert|3|m|in|abbr=on|0}} approximately, 50% of span[4]
|avionics=
}}{{aircontent
|see also=
|related=
|similar aircraft=
|lists=
}}Video"The aerofoil Boat", Lippisch research Corporation (https://www.youtube.com/watch?v=gnflnBF7jWk) References1. ^1 2 {{cite book |title=WIG Craft and Ekranoplan: Ground Effect Craft Technology|last=Yun |first= Liang |author2=Alan Bliault |author3=Johnny Doo |year=1974|publisher=Springer|isbn=1441900411|page=82}}
2. ^1 2 {{cite magazine |date=1 May 1976 |title= West Germany's Aerospace Industry - X-114|magazine= Flight|volume=109 |issue=3502 |page=1168|url= http://www.flightglobal.com/pdfarchive/view/1976/1976%20-%200764.html |accessdate= |quote= }}
3. ^1 {{cite web |url=http://dynlab.mpe.nus.edu.sg/mpelsb/AEG/wigid/LeeQihui.pdf|title=Stability and Control of an Inverted Delta Wing In Ground Effect Aircraft |author=Lee Qihui |date=2006 |work= |publisher= |accessdate=25 September 2013}}
4. ^1 2 {{cite web|url=http://hoverwing.webs.com/ekranoplanvslippisch.htm|title=Ekratoplan Vs. Lippisch|author=|work=|publisher=|accessdate=25 September 2013|deadurl=yes|archiveurl=https://web.archive.org/web/20130904084242/http://hoverwing.webs.com/ekranoplanvslippisch.htm|archivedate=4 September 2013|df=}}
5. ^1 {{cite web|url=http://hoverwing.webs.com/datasheets.htm|title=Hoverwing WIG craft|author=|work=|publisher=|accessdate=25 September 2013|deadurl=yes|archiveurl=https://archive.is/20130927225354/http://hoverwing.webs.com/datasheets.htm|archivedate=27 September 2013|df=}}
}}{{RFB aircraft}}{{Lippisch aircraft}} 6 : Ground effect vehicles|RFB aircraft|German experimental aircraft 1970–1979|Single-engined tractor aircraft|High-wing aircraft|Aircraft first flown in 1970 |