Aircraft and defense giant Boeing (NYSE:BA) reported its annual results with earnings of $1.11 billion dollars. These earnings are just about double last year's results. Investors who consider this particular outcome as being meaningful will be in error, however. From an analytical perspective, this number is the next best thing to worthless, so let's view it, admire it, and move on.

Boeing's earnings per share were $0.86 for the full year. Boeing also received a tax refund from the IRS worth $0.87 per share. Without this tax refund, Boeing would have turned in a loss. If we could count on Boeing receiving a tax refund every year, then this earnings number would be of value. We can't. It isn't. What isn't being reported -- since the "got money from the taxman" angle is so juicy -- is that Boeing also had a one-time adjustment of $1.01 per share to revalue goodwill from an old acquisition. Net out these adjustments alone and you'll already get a much more accurate view of Boeing's results from continuing operations.

Here's my question: Where is the line for the billion dollar plus tax refunds? I mean, I know the answer for this intuitively -- it's just to the right of the line where you overpay your taxes by a billion dollars. This is what happened with Boeing -- the tax refund is the result of a partial settlement of a dispute with the IRS for taxes going back as far as 1992.

This was the first quarterly earnings report for the company since Henry Stonecipher took over last month following Phil Condit's resignation. This has been a horrendous time for the company, having gone through its second high-profile ethical breach in two years, one costing a rocket project that went to rival Lockheed Martin (NYSE:LMT) and losing out on large defense deals from both the Pentagon and the British military. Further, Boeing has lost its status as the largest commercial jet company in the world, as European conglomerate Airbus has surpassed the company.

But Boeing is placing hope for its renaissance in commercial jets with its first new design in more than a decade, the "Dreamliner," or 7E7. Crucial to Boeing's near- to medium-term health will also be the restarting of the Pentagon air tanker deal, valued above $16 billion dollars, in which the company would provide 100 military planes based on the 767 fuselage.

Boeing's commercial airplane unit had sales decreases of 8%, offset by 3% gains in defense. Boeing sees commercial plane deliveries ranging at about 285 for this and next year, nearly matching 2003's results -- 100 fewer than in 2002.

Boeing's results show why it is somewhat dangerous for investors simply to look at price/earnings ratios to determine whether companies are "expensive" or "cheap." The earnings number that will be used for the next 12 months will reflect that massive tax benefit as well as the writeoff. These two events balance each other out to some extent, but someone who doesn't take the time to figure out whether most recent earnings results are based on sustainable or one-time events will be working with a numerator that is quite off kilter.

If you're interested in aerospace and defense, The Motley Fool's Stocks 2004 , our annual investor's guide for the year ahead, offers up some great investment ideas.