Liberty Sport (oz6112)


Liberty Sport (oz6112) by Dick Graham from Sig 1973 - plan thumbnail

About this Plan

Liberty Sport. Radio control scale biplane model for .45 to .60 engines. Kit # RC-33. Wingspan 57in. Note this plan was previously missing sheet 2, so was incomplete. Fixed now.

Quote: "An exact scale R-C that flies like a sport model. A consistent winner in AMA and Sport Scale competition. 1st place at the 1973 National Multi-Wing Championships.

The Liberty Sport is one of the best looking biplanes ever flown. Orval Lloyd, a long-time model builder, with his brother and friends, designed and built the original aircraft in his garage in Mesa, Arizona. First flight was in 1965 and the beautiful aerobatic craft has since been seen at EAA and other fly-ins and air shows. It was exhibited at the 1968 Olathe Nationals, where Dick Graham saw it and decided it was a model that had to be built."

Update 16/11/2014: Added supplement file inc (low res) page 2, thanks to JPM.

Update 19/06/2018: Replaced this planfile with a much clearer, complete plan that includes both sheets, (scanned from fullsize) thanks to Maarten.

Update 23/06/2018: added kit instruction manual, thanks to Jeff Green.

Supplementary file notes

Previous scan version.
Alternate version (low resolution).


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Liberty Sport (oz6112) by Dick Graham from Sig 1973 - model pic


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Liberty Sport (oz6112) by Dick Graham from Sig 1973 - pic 003.jpg
Liberty Sport (oz6112) by Dick Graham from Sig 1973 - pic 004.jpg
Liberty Sport (oz6112) by Dick Graham from Sig 1973 - pic 005.jpg
Liberty Sport (oz6112) by Dick Graham from Sig 1973 - pic 006.jpg

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User comments

It is a pity that original sheet no 2 of plan is missing which covers horizontal tail plane and lower wing to 1:1. I have built Liberty Sport in 1984. It's still in flying condition and looks exactly like the plane in photo by Dick Graham. Sig plans were good and accurate to build. I fitted OS .60 4-stroke which was pretty adequate. The only actual modifications made was to give 1 deg negative incident for flat bottom of Clark Y aerofoiled top wing when fixed, to reduce total of 4 deg decalage of wings created by Clark Y aerofoils when bottoms were on horizontal level. Likewise to datum line to 3 deg and engine inclination down and right 1,5 deg. With original SIG set-up plane tends to jump up every time gas was implemented in the air. Landing of the plane was just a magnificent job to do with modified set-up. She was steady and calm and sit on 3 points. I used CG at point of 7 mm back from leading edge of lower wing which was about 25% point on MAC, calculated based on combined plan view of wings seen from above the wings and indicated by SIG. Lower wing is straight and few cm shorter than top wing and sits as shown on sheet no 1 "side view". It has couple degs of V. Wing N-struts are also angled outwards with some 15 deg. Ailerons only on lower wing. For 4-stroke .60 engine with carburetor behind installation, if I built plane today I would move firewall a bit backwards to give space for carburetor, its control and fuel lines. Top wing is horizontal with no V and swept backwards as shown. Center section which is at 90 deg to centerline of the fuselage is shown correctly in plan and covered by balsa sheets. Both wings have the same size of Clark Y aerofoil. I just wonder should I prepare sheet 2 to show lower wing and horizontal tail based on my plane built from SIG kit? Kind regards from Finland.
EinoRonkanen - 20/11/2017
The supplement file has a low resolution version of page 2. But if you can produce a drawing that has more detail, that would be great, thanks.
SteveWMD - 21/11/2017
Regarding my comment: I did modify aerofoil to be Clark Y. Aerofoils in drawings are modified Clark Y (tail lifted) to give less lift when at 0 deg incident.
EinoRonkanen - 01/12/2017
If someone wants to build Liberty Sport in larger scale than 1:6 it is practical to know wingspan of the top wing of 1:1 protype is 8.7m when scaling the sheets.
EinoRonkanen - 01/12/2017
I had these files in my collection for the Sig Liberty Sport (oz6112) [supp. file & more pics 005, 006]. The instruction manual PDF for this kit is kind of rare, it's not listed or comes up on Google search & such places and to be honest, heaven only knows where I downloaded it from or even when. The photos were pulled off a couple places on the Internet & have been edited for my collection.
JeffGreen_LasVegas - 23/06/2018
Thanks for the files! I am the grandson of the builder of the real Liberty Sport and have wanted to have a model of it. This makes it possibility as the kits are super hard to come by.
Brent - 28/08/2020
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Download File(s):
  • Liberty Sport (oz6112)
  • Plan File Filesize: 3120KB Filename: Liberty_Sport_57in_oz6112.pdf
  • Supplement Filesize: 1141KB Filename: Liberty_Sport_57in_oz6112_alternate_low_res.pdf
  • Supplement Filesize: 4596KB Filename: Liberty_Sport_57in_oz6112_manual.pdf
  • Supplement Filesize: 1542KB Filename: Liberty_Sport_57in_oz6112_previous_sheet_1.pdf
  • help with downloads


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