American Airlines canceled more than 1,000 flights Wednesday, over one-third of its schedule, as it spent a second straight day inspecting the wiring on some of its jets -- the same issue that caused it to scrub hundreds of flights two weeks ago.

Thursday, 14 of 33 outgoing flights out of Hartsfield-Jackson International Airport have been cancelled, according to the airport's Web site. That includes eight of the 11 flights to Dallas Fort Worth International Airport, three of four to LaGuardia Airport in New York and three of six to O'Hare International Airport in Chicago.

LM Otero/AP (ENLARGE)

A worker looks at the tail section of an American Airlines MD-80 aircraft at Dallas Fort Worth international airport in Grapevine, Texas in March.

DELTA NEWS Latest Headlines: Delta to cut capacity, reduce workforce  Delta to restore Atlanta-Mumbai flights Saturday  How Delta, others fit in at small airports  Delta tries to safeguard U.S. employees in Mumbai  Flight attendants union sues Delta over seniority plan  • More Delta news • More business news • Business photo galleries

Delta Air Lines said it also canceled dozens of flights Wednesday while redoing inspections and modifications performed last week on its similar McDonnell-Douglas MD-88 jets. Delta spokeswoman Chris Kelly said the company decided to re-examine the 117 jets in its fleet after being alerted to the issue involving American's jets.

She said Delta discovered that it needed to make modifications on about 20 percent of the jets and expected to complete the work overnight Wednesday.

"We're seeing virtually no customer impact," she said.

The American cancellations included more than a dozen departures from Atlanta, where the Fort Worth, Texas-based carrier is a relatively minor player, and disruptions could continue Thursday. Those cancellations were not causing any major problems or delays at Hartsfield-Jackson International Airport, said spokesman Herschel Grangent.

American, the nation's biggest airline, had already canceled 460 flights on Tuesday, stranding thousands of travelers. Federal inspectors found problems with wiring work done two weeks ago, although the airline says passenger safety was never jeopardized.

The inspections involve American's fleet of 300 MD-80 jets and arose out of concern that Federal Aviation Administration officials had been too lax in overseeing another Texas-based carrier, Southwest Airlines.

American uses the MD-80s mostly on midrange flights, particularly from hub airports in Dallas and Chicago. Spokesman Tim Wagner said 208 of Wednesday's cancellations would occur at Dallas-Fort Worth International Airport and 138 at Chicago O'Hare.

Bishop Bernard Jordan, a Harlem minister, was in a first-class line trying to catch a flight to Atlanta, where he was scheduled to preach Wednesday night.

"It would have been good to know in advance," said Jordan, who said he has 4 million frequent-flier miles with American and flies to Atlanta every other week. "I would have booked with another airline."

-- Information from The Associated Press and staff writers Russell Grantham and Jim Tharpe was used in this article.