The 10-minute aerial debut of the twin-engine Falcon Eagle represents a huge leap forward for China’s ambitious stealth warplane program.

But more than a month after the Falcon Eagle first appeared in blurry photos apparently shot and posted online by Beijing’s army of sympathetic bloggers, there are still more questions than answers about China’s second stealth fighter model.

Is the Falcon Eagle, apparently designated J-31 and not J-21 as we originally reported, a competitor to the larger J-20 stealth prototype that first flew in January 2011?