The United States’ airline industry is not suffering from the 4.3-cents-per-gallon federal tax on jet fuel.

It’s suffering because many of the largest companies have failed business plans that have not been adapted to the realities of the marketplace since deregulation.

The industry early this month asked Congress and the White House to give it a tax gift estimated at $600 million. But the financial turmoil of the airlines won’t be resolved by another raid on the federal treasury.

Rising fuel costs have no doubt hurt the industry, just as they have almost every other sector of the global economy. There is real concern that spikes in gasoline and oil prices could spark significant inflation, leave the poor without means to heat their homes and throw the brakes on an already uneven economy.

But the airlines’ fuel pains are no greater. The bankruptcies of Delta and Northwest are the result of mismanagement and a failure to adapt.

Between 2001 and 2004, the industry has lost $33 billion, even though the U.S. government provided billions in grants and loans after the terror attacks of Sept. 11. Further, because the industry has been negligent in funding its pension obligations, the Federal Pension Benefit Guarantee Corp. is already picking up the tab for United Airlines, for example.

Taxpayers are already on the hook for the poor business practices of several major airlines. Given the cost of the war in Iraq, the recovery in the Gulf Coast and a growing national debt, the government shouldn’t go willy-nilly throwing another $600 million away in corporate windfalls. Tax cuts can’t solve every problem, and they won’t fix the airline industry.