KR2S AS504x Template Application

The following information is provided only as an aid to positioning templates of your own creation (perhaps from the coordinates provided by the UUIAC) onto the KR spars. No claim or recommendation of suitability for any application is implied. Use this information only if you have determined through your own research that you believe this airfoil to be suitable for your purposes. Use them at your own risk.

The AS5046 profile is a best fit for stock KR2S spars. If your spars are already built, you would want to use the AS5046 airfoil. It uses a stock aft spar and a slightly taller main spar, which could be heightened by laminating an extra .125" thick strip of Spruce to the spar cap. The aft spar would also need to be moved up about an inch with relation to the fuselage due to differences in the RAF48 wing shape and the lower incidence that is optimal for the wing. Each airplane varies, and correct incidence will only be achieved using the level lines on the templates, rather than measuring up from the longerons. Several people have cut their aft spars out and raised them, and I'm told it's about a 3 hour job.

The AS5048/15 is 18% at the root and 15% at the tip, hence the name. This would allow a taller spar (but using the same materials as shipped in the spruce kit) and would leave more room for wing tanks and aileron bellcrank. Dimensions for the spars for this setup would be something like 8.19 inches tall for the main spar (caps still 2" thick) at the root, tapering to 5.07" tall at the tip. The aft spar would be 4.77" tall at the root tapering to 2.76 inches tall at the tip, again using stock cap dimensions but with longer and tapered  vertical spacers. Perform your own analysis to ensure that spars of these dimensions are suitable for your use, but generally speaking, taller spars with identical spar caps will be stronger than the original.

Coordinates for all of these airfoils are available if you'd like to plot and print them yourself. Keep in mind that these coordinates are public domain and are provided merely as a convenience, IF you have determined through your own analysis that they are suitable for your use.

If you are interested in these airfoils, please read all of the design information,  including the design criteria and performance curves, to make sure that this is something YOU want to do.

There are were different versions of the templates available for FREE download, for use at your own risk. These airfoil template drawings are public domain, and may be emailed to a printing establishment for printing purposes, or merely point them to this web page. All templates below include the tail templates mentioned above. If you don't understand these templates, just back away from the table and say to yourself "this is not for me". If you have ANY questions whatsoever regarding how to implement them, you need to forget about them and go back to the plans. The files below are intended as a convenience for those who have done their own research and have decided that they want these airfoils for their intended application. If you don't have it installed already, you will need to install the Acrobat Reader for your PC first. After the template is displayed on your screen, you can save it to disk by clicking on the "floppy" icon at the lower left corner of the tool banner.

USE AT YOUR OWN RISK, and do not assume that any engineering, testing, or other groundwork has been done for you.

AS5048/45 pdf file AS5048 at the root tapering to the AS5045 at the tip.  The spar for this set is different from what the plans call for, in that the spruce spacers between the caps must be tapered. It has not been "engineered" nor tested.

AS5046-75 pdf file for those whose tails have not yet been glued in place (probably the most optimal of the two AS5046's, due to improved main wing/tail decalage).

AS5046-00 pdf file for those whose horizontal stabilizers were already fixed at zero degrees of incidence (like the plans call for).

You will need to find a print shop with a roll feed printer/plotter that uses 36" wide paper. These plots are 97 inches long. I have no idea how much they'll charge you. The files are 600 dpi, which is plenty. There are two lines .030" appart defining each airfoil. The inner line is provided in case you accidentally sand the outer one off. It leaves you with some clue as to what the original airfoil was supposed to look like.

The template sets also included REAL airfoil templates for horizontal stabilizer/elevator and vertical stabilizer/rudder. This version of the horizontal stabilizer required a taller spar due to the thicker chord. They are NACA symmetrical series airfoils of the appropriate thickness to match the stock KR (in the case of the vertical) and were thickened to 9% for the horizontal to make them more effective and to strengthen the spars.

Suggestions for template use are located at as504xinst.html and the history of this new KR2S airfoil is located at

If you are stuck with a KR2 wing planform, you'll want a 36" template, so there is a 36" AS5046 outline template, if you don't mind figuring out where the spars are supposed to go, and drawing in an incidence/level line (check the other drawings, but you would probably want something like -1 or -2 degrees).

There is also a AutoCAD14 file and a V14 dxf file that you could scale to make other versions of the AS5046 tip airfoil if you wanted to. Again, you'll have to draw in the spars and incidence/level line (check the other drawings, but you would probably want something like -1 or -2 degrees).