Flyi Inc., the Dulles-based parent of financially troubled Independence Air, may have to pay a fine of as much as $1.55 million for thousands of flights operated last year by its predecessor in violation of government safety regulations.

The Federal Aviation Administration proposed the civil penalty yesterday for violations that included failing to perform safety-related aircraft tests and inspections at required intervals and failing to replace emergency locator transmitters on several of the 50-seat regional jets it flew.

Rick DeLisi, Flyi's spokesman, said the alleged violations involved Independence Air and United Express flights operated by Atlantic Coast Airlines. Atlantic Coast, which became Flyi last year, ran commuter flights for United Airlines and Delta Air Lines.

Flyi said it reported the violations to the FAA itself last October and said the irregularities occurred because the airline was upgrading its record-keeping system.

Flyi took "corrective actions to address the issues . . . and is in compliance with FAA regulations," the FAA said in a written statement.

Airline industry consultant Michael Boyd of the Colorado-based Boyd Group suggested that the fines should not discourage passengers from flying Independence Air, a low-cost carrier that has been struggling financially since its inception in June 2004.

"The FAA fines everybody," Boyd said last night. "The fact that Flyi self-reported this says to me this is a safe airline. Otherwise, they would have tried to cover it up. I mean, believe me, it's not hard to cover stuff up."

The FAA, in a civil penalty letter, charged Atlantic Coast with 10 counts of violating federal aviation regulations. In the past several years, the FAA has issued few fines as large as the one proposed for Atlantic Coast.

One count alleged that the airline continued to operate a jet on 455 flights after a deadline had passed for a "heavy maintenance" check.

Another count said two jets were operated on a total of 630 flights after the deadline for testing a cockpit voice recorder had passed.

"All flights conducted by the company with the affected aircraft during that time period operated normally," Flyi said in a written statement. "Customers were not directly affected in any way."

Flyi has 30 days to contest the charges. The airline said it plans to seek a lower fine.