While the new proposal does respect a few scientific principles, it plays fast and loose with many others. HAC has argued that there are a few anchor points in the fatigue-related science that should be respected. ICAO’s Document 9966 Manual for the Oversight of Fatigue Management Approaches (admittedly, drafted for use by fixed-wing operators – the equivalent helicopters-specific document is under development), at page 8, sets out their foundational principles for the management of fatigue: “1) the need for sleep; 2) sleep loss and recovery; 3) circadian effects on sleep and performance; and 4) the influence of workload.”
Let’s take a closer look at these points:
- Periods of wake need to be limited. Getting enough sleep (both quantity and quality) on a regular basis is essential for restoring the brain and body.
- Reducing the amount or the quality of sleep, even for one night, decreases the ability to function and increases sleepiness the next day.
- The circadian body clock affects the timing and quality of sleep and produces daily highs and lows in performance on various tasks.
- Workload can contribute to an individual’s level of fatigue. Low workload may unmask physiological sleepiness while high workload may exceed the capacity of a fatigued individual.
In some cases they have abandoned the science. Without any discussion, they arbitrarily removed the zeroing provisions in the current regulations. The zeroing provisions recognized the recuperative value of extended days off – to the benefit of flight crews and operators. They provided a natural incentive for operators to provide extended days off between tours. TC is proposing to implement cumulative duty hours, on top of reduced cumulative flight hours.
In the context of most helicopter operations, cumulative duty hours (as opposed to duty day limits) do little to mitigate fatigue where eight hours of regular sleep is protected, each night. But lets look at a few of the specific changes, and some examples, in an operational context for helicopter flight crews:
- Most helicopter operators will opt for “time free from duty option 3” – 192 duty hours in 28 days (or roughly 6.8 hours/day, average) for deployed operations.
- Under the current proposal, flight crews would be limited to 112 flight hours in 28 days, down from 142 in 28 days, currently. However, time free from duty option 3 only allows for 23-day tours (down from a maximum of 42, currently), for an average of 4.8 hours flying time each day on a 23-day tour.
TC’s current proposal for changes to the fatigue management regulations spell disaster for the helicopter industry – and for the customers and communities that we serve. TC should reconsider the option of developing a solution that respects the risk of fatigue, but is better suited to the different segments of the commercial aviation community – and respects scientific principles in an operational context.
Fred Jones is the president/CEO of the Helicopter Association of Canada and a regular contributor to Helicopters magazine.