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Fatigue Risk Management - Eyes Wide Open

As science challenges the traditional rules governing flight time, Charles Tyler examines the implications of proposed new standards in fatigue risk management

Existing crew flight duty and flight time limits are being re-examined in the light of new, more scientific approaches to managing the risk of crew fatigue.
Crew fatigue has typically been controlled by a simple set of prescriptive rules concerning flight time limitations (FTL) and flight duty limitations (FDL). These vary slightly from country to country, but generally limit the total number of hours that flight (and cabin) crew may fly (fly time limits) and be at work (flight duty limits) in a set period.

These rules can sometimes lead to situations in which crew are given rest periods when they are unlikely to be able to sleep. A different system was needed on long-haul flights, where circadian rhythms, which are the body’s natural daily cycles, are interrupted due to time zone changes.

It has been demonstrated that the timing of the break is more important than the duration of the break itself. A prescriptive approach, based only on daily time limits, cannot take into account the complex interaction of factors that are linked to hours of work and rest periods.

In other words, prescriptive rules are not the total solution.  With a well-managed fatigue risk management system, flight duty time and schedule of operation will be optimised, and this enhances efficiency.

Staying safe

Airline safety is the industry’s top priority, and already some states are embracing the wisdom of a more scientific approach to the risk of fatigue. Regulators in these countries are working with their airlines to implement a fatigue risk management system (FRMS), which may either partially or totally replace the traditional prescriptive FTLs and FDLs.

FRMSs generally use biomathematical models that are able to predict the risk of fatigue associated with a specific pattern of working hours. Air New Zealand, which is considered one of the world leaders in this field, started moving in this direction as far back as 1995, when the Civil Aviation Authority (CAA) of New Zealand changed the regulations so that airlines could either comply with the standard prescriptive scheme or apply for an alternative, company-specific scheme, which would have to be approved by the authority.

“The airline industry today is struggling with archaic unilateral limitations that do not reflect its current needs,” says Capt. David Morgan, GM Airline Operations and Safety at Air New Zealand. “We have been operating a comprehensive ‘alertness management’ system for some time now, which appreciates that you become fatigued as a result of many factors. It recognises and mitigates the risks associated with fatigue. We did a lot of work with Qinetiq on this issue, and fatigue mitigation is a key driver in tours of duty from a rostering perspective.”

The carrier has framed its rules in such a way that there are gross flight time limits—1,000 hours per year and 100 per month—but there are none of the traditional limits within a 24-hour period.

“As an operator, we cannot allow our crew members to operate while unduly fatigued,” says Morgan. “We needed to put in place a system that guarantees the well being of our crew, while also addressing our operational requirements. And the scheme also has to ensure that standards are met and sustained on an ongoing basis.” 

Morgan points out that developing an FRMS requires a lot of collaboration between the airline management, the crew and the regulator. As such, a mature approach is required, with subjective feedback from the crew being a vital component.

FRMS systems use many types of monitoring systems, from crew alertness tests to crew rest monitoring, and generally also include some type of crew reporting system. “We trust our crew, and we always react to their observations,” he says. “It has taken us quite a few years to get to today’s level of maturity, and trust in the crew and the system. If we perceive that there is a problem in a tour of duty or over multiple tours of duty, our crew alertness study group may recommend fatigue testing, which objectively measures the alertness of our crew.” An FRMS uses accumulated knowledge to design crew schedules that minimize fatigue, and then continuously monitors the system, making improvements as necessary.

Objective testing during flights is undertaken by using reaction time tests using personal digital assistant devices. Actiographs are wristwatch-like devices that measure when the wearer is asleep and when they are awake. “We also ask pilots to keep diaries of how they feel, and we then take all the information and Qinetiq crunches the numbers for us,” says Morgan. The result is a complex but complete picture of how the crew’s alertness changes through a tour of duty.

Implementing FRMS

IATA is supporting FRMSs. “The bottom line is that safety can be enhanced as we develop the science of fatigue risk management,” says Chris Glaeser, IATA’s Director of Safety.

“We are working to incorporate FRMS into our Safety Management System (SMS), which has been an ICAO standard since last year. This will add yet another layer of safety, and will improve the whole operation.”

As Glaeser points out, the workload on the cockpit of new generation aircraft is different from how it was in the past, with modern avionics and flight management systems. At the same time, the range and capability of ultra-long-haul aircraft means that they are regularly flying 14-16 hour sectors, and even as much as 18-19 hour sectors, which makes a new non-prescriptive approach even more relevant. The new system can provide better-timed rest periods, giving airlines greater flexibility in managing long flights.

Glaeser also points to the current regulations limiting the ability of a single crew to fly a relatively simple return trip on sectors such as London-Moscow or New York-Los Angeles, because they would exceed FTLs. Many states limit scheduled flying time to eight hours a day, even when allowing a 14-hour “duty day”. Using an FRMS to extend the eight-hour flying time limit to nine or 10 hours in a modern, highly automated aircraft would allow pilots to be on duty the same amount of time, allowing them to return home within a normal working day cycle.
IATA is currently producing its first FRMS guide, which will be available this year. This will be part of the IATA Safety Management System series, and it is available for any airline (not just IATA members).

“We are delighted that there was a 17% decrease in global accidents last year, and FRMS is part of our drive to improve the safety of civil aviation,” says Glaeser.


ICAO started to look at crew fatigue seriously in 2003, when the prescriptive rules were revisited and a “best practice” guide was published. ICAO began working with the Flight Safety Foundation, specifically looking at ultra-long-haul operations. In 2006, an ICAO FRM subgroup continued to work on the issue, but realised that the level of expertise required would have to be significantly broadened.

In the summer of 2009 an ICAO FRM taskforce was established, bringing together a team of experts, along with a group of 11 airlines and 13 national regulators at the cutting edge of the field, and various relevant international organisations including IATA.

“It had to be a very multi-disciplinary team,” says Mitch Fox, Chief of Flight Operations with ICAO’s Air Navigation Bureau. “That group has been working diligently. They are totally committed to this, and finalised their proposals for new standards and recommended practice in February 2010. These set out the minimum requirements that operators and regulators would need to operate an FRMS.
“We are now in the process of developing a very detailed global guidance document—a guide for regulators and operators, with detailed illustrations of how the standards can be applied to a wide range of airline operations,” he adds.

Fox acknowledges that an FRMS approach is more difficult and complicated than operating a set of prescriptive rules, but stresses that it can bring great safety benefits. “Standards are conditionally binding and we recognise that some states would want to keep the prescriptive approach,” he says. “So states will have the option of operating either prescriptive rules or an FRMS approach.”
He hopes that a new set of ICAO standards will be adopted by the ICAO Council in spring 2011, and will come into effect that autumn.

Extending the system

At this stage, the FRMS approach is being applied only to flight and cabin crew rosters, but Fox and IATA’s Glaeser believe that it will eventually be appropriate to extend it to all those working in the 24-hour aviation industry, including mechanics, dispatchers and ground crew.

There is no doubt that a scientifically based risk management system can and does reduce fatigue, resulting in improved safety, greater operational efficiency, and better lifestyles for the crew. It is a win-win-win situation for airlines, crew and the flying public.



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