United Airlines and Northwest Airlines also have recently complained of job actions by workers involved in contract negotiations forcing flight delays or cancellations. Unions for both airlines have denied the allegations. On Monday, a judge in Minneapolis was expected to continue a hearing into Northwest's allegations that a slowdown by mechanics was escalating as the nation's fourth-largest airline enters the Christmas travel season. Most airlines rely on overtime by piloty Last week, United, the country's largest carrier, canceled more than 100 flights for two days in a row. Airline officials say United mechanics are defying a November 17 federal court order forbidding an organized work slowdown.
Most airlines rely on pilots to fly overtime hours to staff some regularly scheduled flights.
If Delta's pilots continue to refuse to work overtime, it could cause problems during the upcoming Christmas holiday period, Pate said. The Associated Press . All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. Pages will open in a new browser window External sites are not endorsed by CNN Interactive.