The flight to NY has been cancelled.
The pair are expected to appear at Paisley Sheriff Court on Tuesday.
In February, an American Airlines flight was cancelled after one of its pilots was arrested in Manchester, England.
The legislation covers carrying out pilot duties whereas inebriated or remedy.
A spokesman for Glasgow Airport said: "This morning Police Scotland did attend before the United Airlines flight UA162, going to Newark".
A United Airlines spokesman told The Sun Online: "The safety of our customers and crew is always our top priority". We hold all of our employees to the highest standards and have a strict, no tolerance policy for alcohol.
"These pilots had been straight eliminated from carrier and we are fully cooperating with local authorities. At this time, we are working to get our customers back on their journey as soon as possible".
The limit for alcohol in the breath for pilots specified as 9 microgrammes of alcohol in 100 millilitres - less than half the 22 microgrammes limit for drivers in Scotland. The other, First Officer Paul Grebenc, 35, was jailed for 10 months.
In a similar incident in 2017, two United Airline pilots were jailed for breaching drink-fly limits at Glasgow Airport.
Both had been arrested whereas making ready to retract off from Glasgow on 27 August 2016.