This is going to sound like more bad news for Boeing (NYSE: BA), but bear with me, it gets better. On Monday, China debuted its C919 passenger aircraft at the Zhuhai Airshow. Rivaling the Airbus A320, and Boeing's 737, the C919 threatens to steal market share from a market worth $480 billion in sales over the next 20 years.

Manufactured by Commercial Aircraft Corp. ("Comac," to its friends), the C919 is the same plane we told you about a year ago in Boeing's Chinese Challenge. It's a 160-to-190-seater that China says will cost 10% less to operate than even Boeing's uber-successful redesigned 737, featuring parts supplied by A-list American manufacturers like General Electric (NYSE: GE) and Eaton Corp. (NYSE: ETN).

According to Comac, it could collect hundreds of orders for the C919 over the next six days. Prime targets include China Eastern Airlines (NYSE: CEA), China Southern Airlines, and Air China (natch). But Comac's also hoping to entice partner GE to buy a few dozen planes for its aircraft leasing arm.

In conjunction with China's Aviation Industry Corp. (AVIC) ARJ-21, the C919 forms a two-pronged attack on the West's airplane powers. While Comac tackles the big-plane market, AVIC is hitting 'em low, aiming the ARJ-21 at smaller business-jet makers like General Dynamics (NYSE: GD), Textron (NYSE: TXT), and Embraer (NYSE: ERJ).

Somebody pass the epoxy
"Great!," you grumble. "First melting electrical panels. Now this!" But not so fast.

For all the sound, fury, and sales hoopla, it turns out the C919 isn't really an "airplane" at all. Why, it's not even a complete model airplane. According to those who've seen the "plane," all Comac was able to cobble together in time for the airshow was a full-scale model of "the front half of the fuselage, with a cockpit simulator."

Which I have to say, doesn't sound quite as scary for Boeing investors. Experts today believe the C919 won't make its first test flight before 2014 at the earliest, with actual deliveries not slated to begin before 2016. Plus, seeing as AVIC's ARJ-21 is two years overdue, and Boeing's 787 might be three years tardy before its first delivery, it's clear that these things can take longer than you expect.

Don't discount the threat, but don't make a mountain out of a model airplane, either.

General Dynamics is a Motley Fool Inside Value pick and Embraer is a Motley Fool Stock Advisor recommendation, but Fool contributor Rich Smith does not own shares of any company named above. The Motley Fool has a disclosure policy.

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