More than half of pilots questioned in a new study admit they have fallen asleep in the air.
A survey by the UK pilots' union Balpa also found that of the 56% who have nodded off, 29% say they woke to find the other pilot asleep too.
The results have been published ahead of a European Parliament vote on flying hours.
Former BA pilot Alastair Rosenschein says they are no surprise.
"I don't think I know a pilot who hasn't fallen asleep at the controls at some point or other," he said.
"Pilots are allowed to take short cap naps in this country, most airlines allow that to happen
"The other pilot is watching the shop
"There is a large degree of automation on aircrafts today".