Last week at the Dubai Air Show, Boeing (NYSE:BA) and Airbus landed some jumbo orders, and both are on their way to record years. This should be good news for their suppliers, but a recent change in manufacturing practices raises some questions about their suppliers' future profitability.

Airbus was the big winner at Dubai, but Boeing's 787 Dreamliner is an obvious winner as well, despite the recently announced delay in deliveries. So top suppliers like Honeywell (NYSE:HON) and Parker Hannifen (NYSE:PH) will likely benefit. Honeywell makes avionics, and Parker makes lots of aircraft guts -- things like "electrohydrostatic actuators" -- as well as cockpit displays, brakes, and landing gear hydraulics. Both are working on Boeing's Dreamliner, and you can see the whole international supplier team here.

But an article in Fortune Small Business raised a question in my mind about aerospace suppliers' future profitability. With the Dreamliner, Boeing is outsourcing more than ever. Although the company has relied on suppliers for decades, it now draws on vendors all over the globe. And large vendors are being asked to handle more and more responsibility. Instead of making a set of instruments or two, they're making whole components like a cockpit or a tail section. Boeing now serves more as an assembler of these components and less as a manufacturer.

Does this remind anybody else of the auto industry? For several years, General Motors (NYSE:GM) spun off Delphi, and Ford (NYSE:F) spun off Visteon (NYSE:VC). Both of these then became their primary suppliers. Over the next several years, GM and Ford repeatedly pushed them to take on more and more responsibility, even R&D, while also continually squeezing them on costs.

Now both companies are basket cases. Delphi declared bankruptcy in 2005 and now trades at less than $1, down from around $17 in April 1999. Likewise, Visteon needed a bailout from Ford a couple of years ago, and it now trades at close to $4 per share, down from around $17 in August 2000.

Like the auto industry, the airliner business is mature. Both Boeing and Airbus discount their prices, and both are feeling some pressures from foreign competition like Bombardier and Embraer (NYSE:ERJ) which make regional jets. So, if Boeing and Airbus are following in the footsteps of the automakers, will Honeywell and their other large suppliers suffer the same fate as Delphi and Visteon?

Probably not. The obvious difference is that Honeywell, Parker, and the big aerospace suppliers are huge, well-diversified companies in their own right. Unlike the two big auto suppliers, they aren't overly dependent on one customer. This should give Honeywell and the others more leverage in pricing.

Still, if Boeing and Airbus are farming out production to suppliers all over the world, the pressure to cut costs on U.S. suppliers like Honeywell will mount. So it's worth keeping an eye on their margins to see if any deterioration occurs.  

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Fool contributor Ron Vlieger doesn't own shares in any of the companies mentioned. He welcomes your questions or comments. The Motley Fool has a disclosure policy.