I saw an article about one of Amazon's Prime airplane landing with a smoking brake and I got to wondering just how many planes they have. It turns out that they have 50 right now and by 2021 they'll have 70. I also came across this - Amazon's pilots earn only about 1/4th to 1/3d as much as UPS or Fedex pilots. From what I've read about their pay scales, that doesn't surprise me.
