A long flight can be grueling, especially if you’re stuck in an uncomfortable seat. However, with some strategic planning, you can increase your chances of getting a good night’s sleep and arrive feeling refreshed.
To start, show up at the airport slightly tired. This might seem counterintuitive, but research suggests that being mildly sleep-deprived before boarding can help you fall asleep more easily on the plane. One approach is to stay up later than usual the night before your flight and then wake up early the next morning.
By doing so, you’ll be in a state of mild fatigue, making it easier to drift off to sleep at the unusual hours dictated by your flight schedule. This tactic may offset any discomfort caused by sitting in an upright seat for an extended period. By incorporating this strategy into your pre-flight routine, you can improve your chances of getting a restful night’s sleep during long flights.
Source: https://www.seattletimes.com/life/travel/how-to-actually-sleep-on-an-airplane