Rob Schmitt wrote: >> I used one sheet of aluminum, fairly thin gage as I recall (T6061 0.016 gage >> 3’x3’ sheet worked for me). It spans the back and front spar. It does bend >> down over the front of the front spar and I used a “bar” of aluminum >> probably 1/8” thick by 1” to secure it (Screws) to the front spar. Two bars >> in front, one for the pilot, one for the copilot. The sheet is “V - notched” >> for the center stick opening so that it is continuous at the back of the >> seat but not the front. At the back, the aluminum is also bent down over the >> spar and a “bar” of aluminum is used as well screwed to the rear spar.<<
Just to clarify this, I'm sure Rob doesn't mean to simply cut a v-notch with a pair of tin snips....far better to make the vertex by drilling a hole, then cutting into the hole tangentially with the snips so there's not an actual notch or the stress riser that it would create. Aluminum is not so great at fatigue, so giving it a head start with a real notch (which is likely to become the origin of a crack) is not preferable. Deburring those critical areas is also recommended. A deburring tool is pretty cheap from Aircraft Spruce, and you'll use it many times, once you see how well it works, and understand the concept of why you should remove burrs (which comes after the application of a few Band-Aids, or have seen fatigue failures in critical items). I have to admit that the canvas seat in N891JF works pretty well, and it's been in place since 1990. Whether canvas or aluminum, it's worth inspecting the thing for tears or other damage every year during the condition inspection. Failure at a bad time could ruin your whole day.... Mark Langford, Huntsville, AL ML "at" N56ML.com www.N56ML.com _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
