WOODBURY - ? Three more Southwest Airlines jetliners havesmall, subsurface cracks that are similar to the ones suspected inthe fuselage tear on another of its planes. Federal aviationofficials are considering an order for other airlines to inspecttheir aircraft.

The 5-foot-long hole tore open Friday in the passenger cabinroof shortly after the Southwest plane carrying 118 people leftPhoenix for Sacramento, Calif. It made a rapid descent, landing ata military base in Yuma, 150 miles southwest of Phoenix. No one washurt.

Since then, Southwest grounded 79 other Boeing 737-300s andbegan inspecting them. The grounding caused about 600 flightcancellations over the weekend and another 70 on Monday. Nineteeninspected aircraft showed no problems and will be returned toservice.

Checks on the remaining jets are expected to be completed bylate Tuesday, the airline said.

The incident raises new questions about the vulnerability of thenation's air fleet to fatigue cracks, more than two decades aftercracks caused part of the roof of an Aloha Airlines Boeing 737 topeel open. A flight attendant was sucked out and plunged to herdeath.

AP wire services contributed to this report