WASHINGTON (CNN) -- America West airlines says federal regulators are increasing inspections of its planes -- a practice the airline said is routine when a carrier is engaged in protracted negotiations with its workforce.

In a June 9 memo, the Federal Aviation Administration said it was placing America West under "temporary heightened surveillance," airline spokeswoman Patty Nowack said. Inspections thus far have turned up no significant safety problems and have not resulted in flight delays, she said.

America West is the nation's ninth largest airline. It is currently engaged in contract negotiations with its mechanics and its flight superintendents.

The union representing America West's mechanics says airplane maintenance has suffered since late 1995, when the airline laid off 378 mechanics and began contracting the work to outside shops. The airline quietly ended its contract with one shop because of the quality of work, said Patrick Lacefield of the International Brotherhood of Teamsters, which represents America West's remaining 350 mechanics.

But Nowack spurned the implication that the airline was jeopardizing safety.

"America West has an exemplary safety record and we're proud of that," Nowack said. "We do not compromise safety."

Nowack declined comment on a Wall Street Journal report saying the FAA is seeking to fine the airline at least $1 million for failing to properly oversee the work of outside maintenance contractors. "I know that we have not been imposed any fines," Nowack said.