ORIGINAL: Guitarman52
Great Planes Big Stik 60. It says between 3-3/4 to 4-1/2 inches.
Page 18 of the manual specifies 4" from the LE close to the fuse:
http://manuals.hobbico.com/gpm/gpma1220-1221-manual.pdf
Response from Chad Veich above makes perfect sense.