These are Americans' least favorite airlines in the U.S.

Airline passenger satisfaction has waned over the past year as higher fares, crowded planes and limited flight availability have made the flying experience less than enjoyable, a new study by data analytics firm J.D. Power shows.

While high demand for air travel, coupled with limited supply, is driving carriers' revenue up, customer satisfaction is down and could mar some major airlines' reputations, the report suggests.

"While these drawbacks have not yet put a dent in leisure travel demand, if this trend continues, travelers will reach a breaking point and some airline brands may be damaged," Michael Taylor, travel intelligence lead at data analytics firm J.D. Power, said in a statement.