Why, oh, why, can't I listen to my own advice? In February, I wondered whether Boeing's (NYSE:BA) improving balance sheet would make the stock worthy of my portfolio, but I never took action. Look what's happened since. Sigh.

Bolder investors were probably captivated by the success of Boeing's commercial aircraft group. It's been flying at full throttle all year long. In November, for example, it booked an order from Emirates Airlines for 42 new 777 aircraft and secured purchase rights for up to 20 more of the jumbos. That deal alone could be worth $9.7 billion.

More impressive, though, has been the uptake for the 787 Dreamliner, a twin-engine craft that claims to be at least 20% more fuel-efficient than earlier models. According to The Wall Street Journal, more than 300 of the jets have been sold, creating a revenue backlog that could exceed $46 billion at list prices. (Last year, all of Boeing booked $52 billion in sales.)

Of course, this revenue will be recognized over several years. But that won't matter much if the deals keep coming, which they are. Yesterday brought news of another big order, this time from Australia's Qantas Airways. The Journal reports that the carrier landed an order for 45 Dreamliners and commitments for 20 more. Qantas also acquired the purchase rights to 50 additional 787s. All told, the deal could be worth more than $15 billion at list prices.

So is now the time to get on board with Boeing's stock? There's certainly a case to be made for doing so. For one, the shares trade for 13.7 times trailing 12-month free cash flow. And second, the company posts a 24% return on equity over the same period. Which, in plain English, means there could still be value in the stock. But that's also a thumbnail metric. The shares could just as easily begin a steep descent the minute you find your seat. Foolish investors -- and, yes, I mean you -- had better research well before strapping themselves in.

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Fool contributor Tim Beyers remembers getting a tour of a prototype 777 when the plane debuted. Tim didn't own shares in any of the companies mentioned in this story at the time of publication. You can find out what's in his portfolio by checking Tim's Fool profile. The Motley Fool has an ironclad disclosure policy.