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Johnny Ducati's avatar

When I was a young guy, I reconditioned fixtures to finish grind the root of turbine blades (a sort of Christmas tree shape) for General Electric. I had to hold a 0.0005" tolerance on fixtures that were 3-4 feet across. Only three thousandths total runout was allowed in the final assembly.

The blades and vanes themselves are like works of art, and the investment casting process leaves the internal passages incredibly slick. If you look along the trailing edge, you will see a row of 0.012" holes EDM burned to connect to those internal cooling passages.

That's just one component in an extremely complex assembly, and it is amazing all by itself.

Matthew Green's avatar

Ok, this is very interesting. I have some questions:

1. You repeatedly say that China has “failed” but then proceed to say that they’re about a decade behind. You also point out that the iteration cycle for jet engines is much slower than the cycle for other industries, like EVs. So is China’s current status really “failure” or just part of the expected slow catch-up progress you’d expect in a long-cycle industry?

2. You mention that China has other opportunities they’re risking, and give examples that Western capital is investing in. The two you give are supersonic commercial airliners and autonomous planes/drones. But supersonic commercial airliners don’t seem like an obvious winning bet: given fuel requirements (baked into the physics) they’re a very commercially risky bet, and there’s not much technology can do to change that. Drones are different; but from what I understand, China is not underinvesting there. If anything, Anduril exists as a response to China’s dominance in drones, batteries and other parts of the low-cost military tech stack. Maybe these just aren’t the best examples, but it feels like Western capital is not winning in this area, we’re playing catch up because our big defense contractors were less efficient than state planning by a communist country!

3. This is really the big one I’m curious about: what happens when/if China succeeds at building excellent, commercially-viable jet engines that are cost- and feature-competitive with those built in the West? Specifically, what happens to the Western companies that compete in this area? It seems like they will immediately lose a big Chinese market, not to mention maintenance revenue. Then they’re likely to lose big parts of the non-Western world. For an industry that’s already operating on small margins, can those industries continue to exist (absent direct industrial policy interventions by Western governments?) Does the Western jet engine industry become financially unsustainable? Most critically: does this strategy potentially weaken the West’s ability to dominate this market and also (through that) in some ways limit the West’s military capacity? That seems like it would be more relevant than “ideology” as a reason China might want to pursue this strategy.

Thanks for the article.

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