WASHINGTON (Reuters) - U.S. Transportation Secretary Sean Duffy said on Thursday the Trump administration will take steps to boost air traffic controller hiring after a series of recent safety incidents again raised questions about a persistent staffing shortage.

The Federal Aviation Administration will open its hiring window to become an air traffic controller through March 17, will increase starting salaries by 30% for candidates who go to the FAA training academy and will speed the time-to-hire by cutting more than four months off the old process.

A persistent shortage of controllers has delayed flights. At many facilities, controllers are working mandatory overtime and six-day weeks to cover shifts.

Duffy said he was reconsidering rules that had allowed air traffic control supervisors to reduce staffing at Washington's Reagan National Airport before a fatal Army helicopter-plane collision that killed 67 people in January.

The FAA is about 3,500 fully certified air traffic controllers short of targeted staffing levels and has about 10% fewer controllers than it did in 2012.

The FAA fired 350 probationary workers this month including some with safety-related positions. Duffy insisted that the agency eliminated no jobs critical for safety. USDOT withdrew a retirement offer made to controllers.

This week, a bipartisan group of three U.S. senators called for new funding to boost air traffic control staffing, speed training of new controllers and provide new incentives to retain aviation workers.

Last week, the U.S. aviation sector called for "robust emergency funding" from Congress for air traffic control technology and staffing after a series of crashes.

Airlines for America, which represents American Airlines , Delta Air Lines, Southwest Airlines and other major carriers, praised Duffy's action to address the longstanding shortage of air traffic controllers.

United Airlines CEO Scott Kirby said "addressing the critical shortage of air traffic controllers is the most impactful action the government can take to improve safety, reliability and efficiency for air travelers." American CEO Robert Isom called the plan "a critical initial step to making our aviation system even safer."

In 2024, the FAA cut minimum flight requirements at congested New York City-area airports through October, citing a staffing shortage of air traffic controllers.

In March, former President Joe Biden proposed $8 billion over the next five years to replace or modernize more than 20 aging air traffic control facilities and 377 critical radar systems and to hire 2,000 new controllers. A quarter of all FAA facilities are 50 years old or older.