NEW YORK (TheStreet) -- On his Stop Trading! segment on CNBC Thursday, Jim Cramer said that the Icelandic volcanic ash and debris clouds that have been making their way around Europe and forcing major air transportation hubs to keep planes grounded could hurt major U.S. airline earnings.

As of now, Cramer said, there's no telling how long it will take for the ash to clear from crucial air space.

Airlines that could be affected by this unexpected setback include

Continental Airlines

(CAL) - Get Report

,

UAL Corp's

( UAUA) United Air Lines and

AMR Corp's

(AMR)

American Airlines.

"Those stocks have been red hot. This is going to crimp their earnings," Cramer said, adding that "the airlines have had few instances of sustainable earnings runs."

For Cramer, airline stocks have always been "trading vehicles," rather than "investment vehicles."

On Thursday, Cramer called

Ford

(F) - Get Report

"brilliant." In fact, he said that Ford's next earnings call will be followed by massive credit ratings upgrades.

On Thursday, Cramer also said that he likes infrastructure plays.

-- Reported by Andrea Tse in New York

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