Used to locate pre-drilled holes in the wing ribs, fuel tank covers, panels, skin. Pre-drill the ribs, screw in the back markers, lay the skin sheet over the top, tap with hammer, turn the sheet over, and drill the holes. This is especially useful for rivetnut installation.Due to the large size of the hole required, small errors in location can lead to the "Oh darn, I missed the rib syndrome". Backmarkers save you hours of frustration. 2 sizes of threaded backmarkers are available. Drilling the wing ribs with a 3/32" drill. Drop in the back markers.
Mark the skin by taping with a soft hammer. Turn the skin over and drill the skin with a 3/32" drill. Cleco the skin into position enlarge the holes with #30 drill & cleco.
*THESE BACKMARKERS ARE RIBBED (THREADED). OTHERS ARE PLAIN.
WARNING: The product may contain and/or expose you to a chemical(s) or substance(s) which are known to the State of California to cause cancer and/or birth defects or other reproductive harm. www.P65Warnings.ca.gov
Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.
Unfortunately that part # 04-00131 is no longer available and cannot be sourced. We have corrected our web page. Thank you for bringing this to our attention.