Experts Share Tips on Mitigating Flight Crew Fatigue

Managing crew rest and mitigating risk from fatigue are some of the most challenging tasks for any business aviation flight department. Those tasks can be even more difficult for Part 91 operations that aren’t bound by the regulations governing on-demand, Part 135 commercial charter operators.

“Part 91 has the advantage and disadvantage of being very spartan with respect to fatigue and hours of service regulations,” said Dr. Daniel Mollicone, chief scientist and CEO of Pulsar Informatics. “That provides an opportunity for an operator to develop a fatigue risk management program that exactly meets the needs of their organization.

“The downside is that there’s no standard,” he continued, “so you can have one operator who prioritizes safety [but] another that may not be as well organized.”

“A small flight department can set its own policy,” added Dylan Miller, co-chair of NBAA’s Small Flight Department Subcommittee. “You can set specific limitations that fit your operation, versus being tied to specific numbers. But it certainly takes strong leadership to make it effective.”

That effectiveness, he continued, stems from two important attributes: professionalism and effectively communicating with your principal.

“These are things you don’t learn in flight school,” Miller said. “That’s sometimes a challenge for pilots because every principal is a little bit different. You must figure out how to have conversations with them to establish realistic expectations. Your principal needs to trust you to always approach every flight with safety in mind and make the right decision,” Miller explained.

“I’ve heard some folks tell their principals, ‘There are two people you pay to tell you like it is: your lawyer and your pilot,'” he said. “You’re paying me for my experience and ability to tell you if what you want to do is not safe. A lot of high-net-worth individuals are used to people saying yes, so approaching it from that mindset is important.”

Shifting Schedules

Recognizing how the flexibility provided by business aviation can wreak havoc with flight crews’ rest schedules, NBAA worked with Flight Safety Foundation to develop Duty/Rest Guidelines for Business Aviation, to offer useful tools for flight departments, and especially smaller operations.

“Pilots have a natural mentality to complete the mission,” Miller said. “It often isn’t pressure from the passengers, but pressure they’re putting on themselves to be the person who can complete the job.”

Dr. Steven Hursh, president of the Institutes for Behavior Resources and adjunct professor of Behavioral Biology at Johns Hopkins University School of Medicine, participated on the FAA’s Part 135 Pilot Rest and Duty Aviation Rulemaking Committee (ARC). Their work offers valuable guidance for Part 91 operations as well.

“We are naturally less alert in the middle of the night, which creates a real threat in and of itself,” Hursh said. “When you assign nighttime duty, you are at the same time depriving that person of a prime opportunity for sleep, because our sleep is best at night and less beneficial during the day. It’s a double whammy.

“The more times you do that in a row, the more times you have interrupted their ability to get good sleep,” he added. “The next time they operate at night, they’re going to be even more fatigued because they’ve had insufficient opportunities to get good rest to be prepared for that duty.”

When switching from daytime to nighttime work, “how quickly you adapt is highly dependent on some behavioral choices,” Mollicone said. “The rule of thumb is one hour of adaptation per day. If you’re transitioning from daytime to nighttime shift and you’re now going to sleep eight hours later than before, that’s what we call a phase delay. It may take a full week to fully adjust.”

Hursh noted the ARC also addressed performance in the window of circadian low, which typically occurs between 2 a.m. and 5:59 a.m. “We tried to figure out ways in which those effects can be mitigated so that they can be performed safely,” he said, “but people are simply not as good at operating at night as they are during the day.”

It is critically important, Hursh said, for flight operations to distinguish between rest requirements and the ability to use that time for meaningful, productive and recuperative sleep, without interruption.

“The irony here is that, if you just look at a pilot’s schedule, you’ll see these breaks between duty and you’ll assume that they had plenty of opportunities for rest,” he said. “That presents a distorted view, because the pilot probably is not taking those opportunities to lay down and rest if they weren’t planned in advance.”

Similarly, the ability to rest prior to duty time is more beneficial than rest time afterward. “The rule provides for compensatory rest, but that doesn’t really help when it comes after they were performing their duty,” Hursh said. “Compensatory rest may help to improve the safety of the next operation, but that person was still fatigued during that initial operation.”

Mitigating Risk and Communicating

To combat that risk, Hursh recommended Part 91 operations develop a fatigue risk management plan or alertness management plan that can be tailored to the flight department’s specific flight and duty limits and prescriptive rest requirements to mitigate cumulative fatigue.

“Operators might also incorporate potential fatigue scenarios into their operational risk management procedures addressing other specific risks, such as terrain and weather, which may compromise a crewmember’s ability to handle those risks,” Hursh added.

Mollicone noted such programs can be incorporated into the department’s existing safety management system (SMS). “You must manage fatigue,” he said, “but that can be done within your SMS structure. Why reinvent the wheel?”

“There’s really no one looking over your shoulder at a lot of Part 91 operations,” said Miller. “Even if you have written company procedures about maximum duty time and maximum flight time, those are words in a book on a shelf. You must use your professionalism and judgment to say, ‘This is unsafe, we can’t do this.’”

That said, Mollicone stressed that reliance upon “hours of service regulations is a proxy to fatigue management. They’re a very blunt instrument. Often, you end up with a set of rules that don’t fully address the fatigue risk and constrain your operation with, sometimes, no beneficial impact on safety.”

Striking the right balance is imperative, and pilots must honestly assess their own fatigue level before every flight. “Most pilots – being good, mission-oriented employees – will often go ahead and take a duty,” Hursh said. “The diabolical thing is that, nine times out of 10, it’ll be OK. They get away with it.

“But the next time they do it, when things don’t go as planned, their fatigue undermines their ability to handle the situation quickly and correctly,” he continued. “That’s what we see many times in NTSB reports, too.”

Miller related a flight early in his career with an experienced captain, during which weather and other factors led to multiple delays and running up against their duty time. “Everyone was kind of panicking over when we could finally take off,” he recalled, “but I noticed the captain was very cool and wasn’t getting upset. I appreciated that, but I also wondered why he wasn’t concerned.

“He replied, ‘Never get upset over an argument you’ve already won. At the end of the day, it’s up to us if we’re going to take off – and if we don’t, end of discussion,'” Miller concluded. “The buck stops with you.”