This quote from one of our earliest interviews with a Former VP at TransDigm has stuck with us:

The supply chain in aerospace is actually an inverted pyramid. I recall this from early on in my career, when I was working with one of our legal partners. She said, really, aerospace contracts are an enigma to me. The way they’re written, basically, the supplier seems to be an indentured servant to the OEM. But yet, the supplier is the one that holds all the cards in the agreement so you almost want to be that indentured servant, because the OEM can’t get rid of you. -  Former VP at TransDigm 

This analysis shares a brief history of the commercial aerospace value chain as context to why OEM suppliers like TransDigm continue to enjoy pricing power in the aftermarket.