Not overly so. If it was clear a bubble happened, we would have time to adjust production rates [by canceling planned increases]. If the world changes, we will change. But remember, roughly two-thirds of demand is for replacements. And part of the shorter cycle you're talking about is highly capable airplanes replacing less capable ones. In an era of high oil prices, the payback is very quick.

The economic lives of used jets are expiring much sooner than expected due of oil prices and technological advances in new aircraft. Given that shift, might Boeing bring an all-new successor to the MAX to market sooner than conventional wisdom would suggest?

It depends on the premium the new airplane can provide, and that gets into engine technology, technical evolution and other improvements—how much performance we can get out of a composite airframe and wing. I think the absolute earliest would be the mid to late 2020s. But the real answer is that I don't know.

What about the widebody market? You've had some 777 cancellations this year.

You need to look at Boeing's market share over the last 2-3 years and the potential based on orders and production ramp-ups. There's a significant opportunity to be the market-share leader and winner for a long period of time in widebodies. You can see the beginning of that over the last couple of years.

Speaking of widebodies, can you give us a sense of timing on the 787-10X and the 777 response to the A350?

We're still sorting through the technical costs and timing of both of those, and we are watching the competition and trying to assess what they're going to come up with [on the A350-1000]. Supply chain is a bigger issue on the 777, especially if we go in the direction of a composite wing and other [enhancements]. I would characterize the 777 as a medium-risk proposition and the 787-10 as low-risk. So it gets down to cost, risk, competitive timing and customer demand. The one we don't fully understand yet is competitive timing.

You've put out a request for proposals for a next-generation 777 engine. Do Rolls-Royce or Pratt & Whitney have something interesting to offer that could unseat incumbent General Electric?

We're very happy with GE on the current 777. They have deep knowledge of the application, an engine we like and the evolution of the engine gives them a strong case. But we're going to listen to what the other guys have to say, because they've also been evolving technology. If one of them has a significantly better or more reliable engine, we'd have to think about our customers. A number of new large engines have been developed since the GE90 family.