By David Millward
Two pilots fell asleep on a flight it has emerged, as a study revealed that one in five has complained of fatigue.
The incident took place on a long haul flight three months ago, although neither the airline nor the route has been disclosed.
According to the pilots union, BALPA, there is a growing problem of fatigue among flight crew.
It has voiced concern that this will worsen under EU proposals to increase flying hours from 900 hours every 12 months to 1,000.
A study commissioned by BALPA and carried out by University College, London, has found that one in five pilots complain of tiredness.
It sent a questionnaire to pilots working for one major airline and received a 47 per cent response.
Of the 492 pilots who participated in the survey, 45 per cent said they suffered from “significant fatigue”.
One in five said that their ability to fly an aircraft was “compromised” more than once a week.
Modern aircraft now rely on an autopilot system, which kicks in within a few minutes of take off and follows a predetermined route.
Nevertheless the flight crew still monitor the flight and be in a position to override the automated system when necessary.
One pilot who did not want to be named, told the BBC that both he and his co-pilot had been asleep during a flight.
After getting very little sleep during their rest period the co-pilot took a scheduled break to take nap on the subsequent flight.
The pilot then fell asleep for about 10 minutes.
"When I woke up, it was a big adrenalin rush. The first thing you do obviously is check your height and your speeds and all of your instrumentation," he told the BBC.
"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."
Currently the rules governing pilots flying hours are stricter than elsewhere in Europe and are under threat by the EU desire to standardise the regime across member states.
It has led to pilots accusing the EU of caving into pressure from airlines who want to cut costs.
In late 2009 pilots’ unions across the EU have also accused the European Aviation Safety Agency of failing to act after a study it commissioned had described the existing 14 hours maximum shift as excessive.
European Cockpit Association, which represents pilots, have insisted that the study strengthened the case for stricter laws on the hours which pilots are expected to work.
According to BALPA pilots on short haul flights within Europe can be asked to do three flights a day.
While the problem with pilots working on long distance destinations is a lack of sleep between flights, caused in part by disruption to their body clocks.
“Fatigue amongst pilots is a real worldwide problem among pilots right now,” said Jim McAuslan, BALPA ’s general secretary.
“Tiredness is now accounting for between 15 and 20 per cent of accidents. Now incredibly the EU wants to increase flying hours.”
Late last year the Daily Telegraph disclosed that dozens of pilots were falling sick in mid-flight every year.
In 2009 were 32 occasions in which a pilot was incapacitated last year, 17 fewer than the previous year. In 2007 there were 39 instances reported to the Civil Aviation Authority.
On the other hand Michael O’Leary, the outspoken chief executive of Ryanair has suggested that co-pilots could be better deployed during flights helping cabin crew serve tea, coffee and snacks to passengers.
