Presidential candidate Alexander M. Haig Jr., violating the GOP's 11th commandment against criticizing a fellow Republican, last night charged that Vice President Bush has failed every task he has been assigned by President Reagan.

Haig cited Bush's assigned responsibilities of dealing with regulatory relief, crisis management for Lebanon, control of drug trafficking and fighting terrorism.

Noting that Bush, the front-runner for the 1988 GOP presidential nomination, has described himself as the Reagan administration's "copilot" who knows how "to land in a storm," Haig said in remarks prepared for delivery to a fund-raising audience in New York City that, in the missions he was assigned, Bush either "wasn't in the cockpit," flew in the "wrong direction" or "crashed."

Haig, national security adviser and chief of staff for President Richard M. Nixon and Reagan's first secretary of state, questioned whether Bush is "tough enough to deal with the economy . . . tough enough to deal with {Soviet Leader Mikhail} Gorbachev . . . tough enough to beat the Democratic candidate."

Announcing that he was violating the "so-called 11th commandment, not to speak ill of other Republican candidates," Haig noted that Senate Minority Leader Robert J. Dole (R-Kan.), another GOP presidential contender, had complained that Bush "has a resume but no record."

"Bob's wrong on that one," Haig contended. "George Bush does have a record, and that's the trouble."

Haig said that in Bush's first assignment, head of the administration's Task Force on Regulatory Relief -- which was supposed to shrink government and get it "off the people's backs" -- Bush spent 2 1/2 years producing a 126-page report.

"It's a big, thick report," Haig said. "But it's not as big or thick as the regulations that remain on the books, untouched to this day."

He quoted critics who described Bush's effort to reduce the size and scope of governmental regulations as an "aspirin when we needed major surgery." And he charged that the administration "had a great opportunity and missed it."

As chairman of crisis management throughout the Lebanon crisis, Haig charged, Bush was giving "mixed signals, the policy-a-day syndrome" and of making the nation "connoisseurs of confusion."

"The policies snatched defeat from the jaws of victory, letting the Syrians run us out of Lebanon after the slaughter of our brave, young Marines -- providing a victory for terrorism and a disaster that has hurt our standing in the Middle East to this very day," Haig said. "Clearly, the copilot was in the cockpit on that one and the plane crashed."

Haig accused Bush of advocating the wrong strategy for drug control as chairman of the South Florida Task Force on Drugs.

"George is proud that we've been cracking down on drug dealers," he said. "Busts are up. But so is usage, especially of cocaine. And prices are down."

Haig argued that the solution was to go to the source, "the countries of origin. We did that 24 years ago in Turkey and in Southeast Asia and it made an important difference."

Haig reminded his audience that in the recent NBC candidate debate, he asked Bush, who was chairman of the Task Force on Combatting Terrorism, how he had advised Reagan on the controversial deal to sell arms to Iran in exchange for freeing Americans held hostage in Lebanon.

"I asked the vice president, 'What did you advise the president on the Iran deal and if you did not, why not?' George Bush did not answer my question, but he must. He's running for president now . . . . Where was George Bush during the storm? Was the copilot in the cockpit? Or was he sitting back in economy class?"

Haig also accused Bush of dismissing the Republican Party principle of "linkage" of Soviet aggression and repression with arms control and asked whether Bush has been "charmed by the smiling Mr. Gorbachev? . . . . Is he the man to deal with Soviet aggression, to sit across the table from Gorbachev?"