Amazing company really. They not only manufacture their parts, but also invent them and hold patent on them. Their strategy is to sell parts for a new airline at a slight loss, to prevent competitors from entering - this is the first few years. Then for the next couple of decades of the life of the airplane, they are the only source for replacement parts. High margins, no competitor to speak of, religious price increases year after year. Airlines may hate them, but can't get rid of them.
A competitor would have to design their own parts, have them FAA approved, convince airlines to buy it from them instead of a reputed leader like TransDigm and of course they have to be better/cheaper than TransDigm. Really a one-of-a-kind company.
