Air Canada\'s 3,800 sales and customer service agents went on strike Tuesday, causing flight delays but no cancellations, after contract talks ended in failure. \"We will keep pushing the employer to get back to the bargaining table, Canadian Auto Workers President Ken Lewenza said. Airline spokesman Peter Fitzpatrick said it was \"unfortunate that the CAW chose to put ideology ahead of their members\' interest,\" the Toronto Star reported. Lines were long for travelers early Tuesday, as Air Canada management staffed passenger check-ins and plane boarding. The airline -- Canada\'s flag carrier and largest airline -- advised travelers on its Web site to check in online up to 24 hours ahead of a flight, arrive at the airport much earlier than usual and, if possible, carry baggage instead of checking it. The two biggest stumbling blocks between the union and the airline, which filed for bankruptcy in 2003 and emerged in 2004, were wages and pensions, including a proposal to move new hires to a defined contribution plan from a defined benefit plan with a guaranteed payout. Lewenza told CTV News his members would not negotiate those pension benefits away.