Not a very significant part of an airplane, but airplanes are made up of a multitude of parts that on their own don't seem very significant.
So why are tabs worthy of our consideration?
Weight and corrosion protection are two reasons.
I grew up with Cubs. Great airplanes, but poorly built. Corrosion is a huge problem with them. I maintained and restored them and became frustrated at having to do major structural repairs due to corrosion. That corrosion was due to poor building and design practice. To be fair, they lasted far longer than the manufacturer ever intended. But we are building custom homebuilts, and we can invest the time to make our airplanes MUCH better than the "factory builts".
Two problem areas are behind framework and holes drilled in tubes for screws. It should be obvious that a tab welded on holding a nutplate is better than a hole in the tube that will allow water in, and internal corrosion.
Often a frame strip is welded to a tube to form a door or window frame, but there is not good enough access behind it to properly clean and paint, so it rusts from the day it leaves the factory. This can be remedied by using tabs instead of a strip or holes in tubes. Then if a frame strip is needed it can be made of lighter aluminum and screwed or riveted to the tab after the frame is painted. In some cases, like a window frame that will have to resist the pull of tight fabric, the welded on frame strip may be required. if it's just an attachment for an aluminum panel, no tension, then tabs probably would do. If a strip has to be welded on, consider spacing it off the tube 3/16" so you can sandblast and paint under it.
Here are some examples. These are just my opinions, I hope they give some ideas.
( Sorry , in the bottom drawing it should say 3 angles not 2.)
So why are tabs worthy of our consideration?
Weight and corrosion protection are two reasons.
I grew up with Cubs. Great airplanes, but poorly built. Corrosion is a huge problem with them. I maintained and restored them and became frustrated at having to do major structural repairs due to corrosion. That corrosion was due to poor building and design practice. To be fair, they lasted far longer than the manufacturer ever intended. But we are building custom homebuilts, and we can invest the time to make our airplanes MUCH better than the "factory builts".
Two problem areas are behind framework and holes drilled in tubes for screws. It should be obvious that a tab welded on holding a nutplate is better than a hole in the tube that will allow water in, and internal corrosion.
Often a frame strip is welded to a tube to form a door or window frame, but there is not good enough access behind it to properly clean and paint, so it rusts from the day it leaves the factory. This can be remedied by using tabs instead of a strip or holes in tubes. Then if a frame strip is needed it can be made of lighter aluminum and screwed or riveted to the tab after the frame is painted. In some cases, like a window frame that will have to resist the pull of tight fabric, the welded on frame strip may be required. if it's just an attachment for an aluminum panel, no tension, then tabs probably would do. If a strip has to be welded on, consider spacing it off the tube 3/16" so you can sandblast and paint under it.
Here are some examples. These are just my opinions, I hope they give some ideas.
( Sorry , in the bottom drawing it should say 3 angles not 2.)
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