My 91 -4 had a bolt and nut with no notch in the attach bracket between fuel tank and fuselage. I can't find a service bulletin on making the update like the current plans call for which is to notch one of the brackets and use a plate nut. This allows for the wing and fuel tank to separate from the fuselage in a crash so the tank doesn't rupture.
What I am having trouble with is which do you notch and which gets the plate nut? I think you notch the mount on the fuse and put the plate nut on the tank which would be similar to this setup I found a picture for online of an RV-7. However, I also found this picture of an RV-8 tank that shows the tank bracket slotted.
The RV-4 electronic plans aren't much help, or at least not the pages I've found. It seems that both the fuse and tank might share the same part number (T-405). There is one picture on drawing 17A giving dimensions of it and this is the fuel tank drawing but no reference to a plate nut or notch. Then in the fuse section of the plans it talks about referring to drawing 39 which as the same part number referenced (T-405) and shows the slot.
Can someone confirm if I should be putting the notch/slot in the fuse side and plate nut in the tank, or vise versa (or something totally different)? If there was a service bulletin for this update, please reference it here, too.
What I am having trouble with is which do you notch and which gets the plate nut? I think you notch the mount on the fuse and put the plate nut on the tank which would be similar to this setup I found a picture for online of an RV-7. However, I also found this picture of an RV-8 tank that shows the tank bracket slotted.
The RV-4 electronic plans aren't much help, or at least not the pages I've found. It seems that both the fuse and tank might share the same part number (T-405). There is one picture on drawing 17A giving dimensions of it and this is the fuel tank drawing but no reference to a plate nut or notch. Then in the fuse section of the plans it talks about referring to drawing 39 which as the same part number referenced (T-405) and shows the slot.
Can someone confirm if I should be putting the notch/slot in the fuse side and plate nut in the tank, or vise versa (or something totally different)? If there was a service bulletin for this update, please reference it here, too.