One in five pilots suffer from fatigue in the cockpit at least once a week, a study seen by the BBC suggests.

The study, commissioned by the British pilots' union, Balpa, and carried out by University College London (UCL), is due to be released on Thursday.

Balpa is worried the situation will get worse if European proposals regarding flying hours come into force.

But European authorities claim the proposed changes will not lead to a reduction in safety.

The study by UCL sent questionnaires to pilots working for a major British airline.

A total of 492 replied, which marked a 47% response.

Some 45% of those said they were suffering from significant fatigue. One in five reported their abilities were compromised in flight more than once a week.

'I fell asleep'
One pilot who works for another large UK airline, but who did not want to be named, told the BBC that, about three months ago, both he and his co-pilot had very little sleep during their rest period.

On the subsequent flight, his co-pilot asked if he could take a nap, which the pilot approved. But then the pilot fell asleep too - for about 10 minutes.


The problem with fatigue is that it slows your reactions down”

Dave Smith
Balpa
"When I woke up, it was a big adrenaline rush. The first thing you do obviously is check your height and your speeds and all of your instrumentation," he said.

"The worst scenario is that the autopilot would disconnect itself and then the aircraft would lose or gain height and that would be extremely dangerous as you'd go into the path of oncoming aircraft.

"Now there are warning systems that tell you you are deviating from the correct altitude but they are not excessively loud - it would be easy enough to sleep through that, and I probably don't need to tell you what the consequences of that are."