FlyersRights.org said American Airlines, American Eagle, United and Delta routinely denied passengers an opportunity to deplane at a diverted airport from October 2008 to March 2009, according to the advocacy group's analysis of Department of Transportation data.
Other airlines almost always gave passengers the option to wait out the diversion in the comfort of an airport terminal, FlyersRights.org said.
The group analyzed the latest data installment for diverted commercial airline flights. (Diverted flights make unscheduled stops before they reach their final destination because of a weather problem or other in-flight emergency.)
The DOT has been keeping detailed statistics for diverted flights for the past six months.
DOT data shows that American, American Eagle, Delta and United accounted for 735 instances of failing to give passengers the opportunity to deplane at a diverted airport, said the advocacy group.
Meanwhile, the other 15 airlines accounted for only nine instances between them, FlyersRights.org reported.