Delta Air Lines (NYSE:DAL) will likely not add much to its schedule for the remainder of the year beyond the 1,000 new flights in late summer it has already announced, a reminder of the prolonged impact COVID-19 will have on the industry.

In recent weeks, airlines have been slowly rebuilding their schedules as travel demand begins to climb off of April lows, but Delta CEO Ed Bastian told employees on Thursday that he believes the airline is "at least two years away from a return to normal."

A Delta jet parked on the tarmac.

Image source: Delta Air Lines.

Airlines are taking steps to restore consumer confidence in flying, including limiting plane capacity and requiring the use of masks. But with cases spiking in a number of key tourism-focused states, it remains possible that traffic levels will not recover as quickly as some investors have hoped.

Bastian said that the plan to add up to 1,000 flights by August is still on, but Delta does not expect to add significant additional capacity beyond those flights for the remainder of 2020.

A slow recovery would likely be bad news for both employees and investors. Delta said last week it believes it can cut its cash burn to zero by early 2021 either by increasing revenue or by cutting expenses. If revenue does not return heading into the fall, the chances rise that Delta and other airlines will look to do significant headcount reductions before year's end.