Canadian regulations haven’t caught up with how much science is learning about the impact of sleep deprivation on performance, reports W5.

For example, a flight departing Toronto for Rome requires two pilots under the new and existing regulations. Under American regulations, a third would need to be on board from New York to Rome in case the captain or co-pilot suffers from fatigue and needs to nap.

What many passengers may not realize is that Canadian pilots are permitted to sleep on the job under a system called “controlled rest.” It’s up to the pilot to self-assess whether they need to nap, and they’re permitted up to 40 minutes on a flight.