The Air Line Pilots Association said Monday's deal will let United spread a reduced amount of flying across the airline's 13,000 pilots to save jobs at least until next June.
"Our members understood that in order to protect pilot jobs, we needed to approve this agreement,” said Todd Insler, chairman of the union's United Airlines council.
The agreement was ratified by about 58% of the pilots who voted on it.
It comes as United, American and some smaller airlines prepare to shed thousands of workers on Thursday, when $25 billion in federal pandemic-relief aid and a related prohibition on furloughs expires. The airlines and unions are lobbying for $25 billion more to delay furloughs for another six months, through next March, but the fate of their campaign is uncertain and time is running out.
U.S. air travel remains about two-thirds lower than it was a year ago, and United executives do not expect travel to even approach pre-pandemic levels until a COVID-19 vaccine is widely available.
Chicago-based United is still poised to furlough nearly 12,000 flight attendants, mechanics and other union employees starting later this week. Company officials said 7,000 workers took buyouts and others are taking long-term leave.
Pilots have special training requirements that make it more difficult and time-consuming to bring them back, which gave the pilots' union more leverage to negotiate a jobs-saving deal.
The agreement, which union negotiators reached earlier this month, includes another chance for pilots over 50 to take early retirement. About 94% of United pilots took part in the ratification vote.