United Airlines is setting an earlier cut-off time when pilots must stop drinking alcohol before flights.
The airline is telling pilots they must abstain from alcohol for 12 hours before flights, up from a previous ban lasting eight hours.
The change in the so-called bottle-to-throttle rule comes after two United pilots were arrested in Scotland and charged with suspicion of being under the influence before a flight to the U.S.
The old 8-hour limit complied with Federal Aviation Administration rules, which also prohibit pilots from flying with a blood-alcohol content at or above 0.04%.
A United Airlines spokesman says the new policy was sent to pilots a week ago and took effect last Saturday.