Pilots on more than one in 20 Cathay Pacific flights suffer from at least a moderate degree of fatigue when they begin their descents to airports, a groundbreaking survey has found.

The survey - conducted between November and December last year and analyzing 372 Cathay Pacific flights in detail - found that pilots on 21, or 5.6 percent of, flights were fatigued when at the top of their descents.

Pilots filled out forms volunteering information about how tired they felt at the top of descent in the survey, believed to be the most detailed conducted by any airline into the issue of cockpit fatigue.

The survey measured fatigue on the Samn-Perelli scale of one to seven which ranks one a fully alert, two as very lively but not at peak. Three as okay, four as a little tired, five as moderately tired, six as extremely tired and seven as completely exhausted.

Pilots on 5.6 per cent of flights returned a Samn-Perelli score of five or greater, which in a circular to crew, General Manager Flying Henry Craig described as "very encouraging".

An analysis of the results, seen by the China Daily, found that the passenger flights which were most "problematic" in terms of pilot fatigue were overnights from Delhi and Mumbai to Hong Kong, including ones going via Bangkok.

The pattern for another problem flight going from Colombo in Sri Lanka to Hong Kong via Hong Kong has been altered already because of fatigue problems and continues to be monitored, the analysis said.

The survey was part of a comprehensive fatigue study initiatedby the airline in response to concerns over the difficulties faced by crews flying across multiple time zones, as reported by the China Daily last December.

Responding to the survey, a senior source within the Hong Kong Airline Pilots Association (HKALPA) pointed out that the scores of 5 or above on the Samn-Perelli scale were "a long way off falling asleep on the flight deck".

"We are much further down the track in understanding our fatigue issues and are currently trialing advanced software to assist us in 'proactively' reducing our fatigue profile even further," the source said. "In this respect, Cathay Pacific remains an industry leader in tackling fatigue head on."

China Daily

(HK Edition 10/04/2011 page4)