The nation’s largest airline has now canceled a total of more than 2,400 flights since Tuesday, after FAA regulators implied that nearly half its airplane fleet could violate a safety regulations.

Shares of AMR stock fell more than 11% on Wednesday, recovering over 6% in morning trading on Thursday.

The fallout of the outages for AMR’s second-quarter financials should be even greater. In times of high fuel cost, airlines must cram each plane as full with passengers as they can, scrapping under-booked flights. Assuming just 100 passengers on each of the 2,400 canceled flights, over 240,000 people, each spending just $100 per flight, gross revenues would take a hit of a minimum $24 million — not counting vouchers for meals and accommodations.

With a price-earninge ration of just 5.47, AMR would now qualify as a “value stock” to those cherishing arbitrary numbers fetishes as salutary indicators of a stock’s inherent value. Indeed, given today’s impressing rebound in the face of more bad news (and medium-term fall-out), there seem to be plenty of traders who consider the recent low of $8.10 a bargain for a company that hit $34 just a year ago.

But given the outlook for U.S. consumer spending (especially on travel) and soaring gas prices, I believe the airline industry as a whole will dive-bomb into a sea of red ink by summer. (I said this much in the upcoming TFN 60-Second Buzz… which I taped before the AMR troubles hit.)

Unless you’re shorting the stock awaiting further bad news, I’d not put a dime into airline stocks just yet. No matter how cheap, you can always lose another 90% of principal…