I cut a second access hole in the wooden work floor that fits into the aft fuselage. This will allow me to install the strobe package in its new location, one bay forward of where it was originally going to be located. (This move was required by the magnetometer's requirement for 18" of space between it and any ferrous material or power supply.)
I measured between the longerons and cut up some scrap 1" angle. I'll rivet an angle on each longeron, and the existing mounting plate will be re-used.
