Transportation Secretary Sean Duffy and Vice President JD Vance joined President Trump on Sunday in blaming diversity hiring practices at the Federal Aviation Administration for the midair collision of a commercial jet and a military helicopter near Washington last week.

“The person at the controls didn’t have enough staffing around him or her because we were turning people away because of D.E.I. reasons,” Mr. Vance said on Fox News, using the abbreviation for diversity, equity and inclusion. “D.E.I. policies have led our air traffic controllers to be short staffed — that is a scandal.”

On Thursday, Mr. Trump, without evidence, linked his long-running complaints about diversity hiring practices to the crash near Ronald Reagan National Airport. The president quoted from the F.A.A. website, which he said had indicated that the agency was looking to hire people with disabilities.

No evidence suggests that diversity hiring programs contributed to the crash on Wednesday night. Those programs — some of which started or continued under Mr. Trump’s first term — followed the same aptitude, medical and security standards used for hiring candidates without disabilities.

In 2019, for example, a pilot program that the F.A.A. began for hiring 20 people with disabilities emphasized that those candidates would “receive the same rigorous consideration” as those considered for “a standard public opening for air traffic controller jobs.”

But on Sunday, Mr. Duffy suggested without offering evidence that efforts to diversify hiring had affected the quality of the work force at air traffic control towers.

“You can’t focus on diversity, equity and inclusion when you try to hire air traffic controllers,” Mr. Duffy said on Fox News. “You focus on the best and the brightest.”

Michael McCormick, a former vice president of the F.A.A. Air Traffic Organization who oversaw hiring of controllers during his tenure from 2011 to 2015, said in an interview that Mr. Trump, Mr. Vance and Mr. Duffy were making “baseless claims.” He characterized diversity programs as a recruitment tool for reaching out to candidates with minority backgrounds and said they did not compromise hiring standards.

When the F.A.A. makes a hiring decision after air traffic controller candidates go through training, he said, the agency “does not take into account gender, age, race, creed, color” but solely considers “the merits and the abilities of the individual.” Mr. McCormick worked for the F.A.A. for more than three decades and now teaches at Embry-Riddle Aeronautical University.

On Sunday, Mr. Duffy also criticized the Biden administration for changing some aviation terms such as cockpit and Notice to Airmen — the system notifying air industry members of potential hazards — to more gender-neutral terms such as flight deck and Notice to Air Mission. He suggested without offering evidence that such changes had shifted focus away from ensuring the highest levels of aviation safety.

“When you don’t focus on safety and you focus on social justice or the environment, bad things happen,” Mr. Duffy said on CNN.

Senator Eric Schmitt, Republican of Missouri, echoed the Trump administration officials in pinning the blame on diversity and inclusion programs for low staffing, and claimed that a focus on such programs hurt recruitment and retention.

“D.E.I. is poison,” Mr. Schmitt said on NBC. “Merit has taken a back seat to quotas.”

But no such quotas exist for hiring air traffic controllers, Mr. McCormick said. Recent staffing shortages around the nation’s air traffic towers have been caused by years of employee turnover, lack of funding and difficulties with in-person training during the coronavirus pandemic, not by diversity hiring practices.