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.

Eight out of ten pilots also believe their flying abilities have been compromised by tiredness in the past six months. And three-quarters of British pilots have said they do not trust the European regulator in its role as the aviation safety body for Europe.

The survey was of 500 commercial pilots and conducted by ComRes on behalf of BALPA.

It found that:

• 56% of pilots admit to having fallen asleep on the flight deck and, even more worryingly, of those who admitted this nearly 1 in 3 (29%) said they woke to find the other pilot asleep
• 43% said they believed their abilities have been compromised at least once a month in the last 6 months by tiredness, with 84% saying it has been compromised during the past 6 months
• 31% don’t believe their airline has a culture that lends itself to reporting tiredness concerns with only a half (51%) saying they believed their airline Chief Executive would back them if they refused to fly because of tiredness

49% said pilot tiredness was the biggest threat to flight safety, three times more than any other threat

BALPA has called on MEPs voting in the EU Transport Committee on Monday to back a motion that would require the European Commission to withdraw its proposals and to subject them "to proper scientific and medical scrutiny".

Jim McAuslan is General-Secretary of BALPA. "Tiredness is already a major challenge for pilots who are deeply concerned that unscientific new EU rules will cut...standards and lead to increased levels of tiredness, which has been shown to be a major contributory factor in air accidents".

Former British Airways pilot Alastair Rosenschein says the findings are no surprise.