Air travel is taking off, with the Transportation Security Administration screening more passengers in March than at any time in the past year. Now factor in this: The Centers for Disease Control and Prevention announced Friday that fully vaccinated travelers are less likely to get and spread COVID-19, and so, it says, those travelers do not need to get tested before or after travel unless their destination requires it, nor do they need to self-quarantine.

It all adds up to an expected boom in air travel for spring and summer. But will airlines be ready after furloughing tens of thousands of workers and pausing training and hiring programs?

The issue may be especially acute when it comes to hiring pilots because airlines say they’ll have to hire thousands of them. But those pilots may not be in the pipeline. 

There are several reasons. One is that airlines used to recruit a lot of pilots from the military, said travel industry analyst Henry Harteveldt. But after years of airline bankruptcies and mergers, fewer of them are joining commercial fleets.

“The military pilots looked at the airlines and said, ‘You know, the bloom is off that rose. I’m going to stay in the military and complete my career as a pilot here,'” Harteveldt said.

Another reason, according to airline industry analyst Robert Mann, is that many airline pilots who were already close to retirement age just went for it when the pandemic hit.

“Their companies made it either an economic imperative or an economic opportunity to retire early,” Mann said.

In fact, about a thousand pilots retired from United Airlines alone since September. And on Thursday, United told employees it was hiring 300 pilots immediately. 

But filling all open jobs may be tough. It’s not easy or affordable to become a pilot, said Faye Malarkey Black with the Regional Airline Association.

“This career path unfortunately has historically very much been set aside for the elite, families that have either private wealth or access to private capital,” she said.

Aside from education, there is training, logging hours of flight time, paying for insurance. Malarkey Black said most student loans don’t cover those extras, so they’re often out of reach for lower-income students, including those of color. About 3% of commercial pilots in the U.S. are Black. 

She said that it should be a goal to create as much diversity in the staff of the flight deck as you see in the cabins. To help achieve that, she said, the airline industry needs to pick up with training programs that paused in the pandemic.