Decades-old Part 135 pilot rest and duty regulations may soon give way to a more progressive set of science-based rules. Current regulations, according to experts, are far too prescriptive and fail to recognize the effects of circadian rhythm and cumulative duty time. A new set of rules is soon expected to enter the notice of proposed rulemaking process and would be based on modern fatigue science while accommodating the diversity of operations within the charter and air ambulance industry.
In July 2021, the Part 135 Pilot Rest and Duty Rules Aviation Rulemaking Committee (ARC) submitted its recommendations to the FAA, after nearly three years of collaborative industry work. Established by the FAA Reauthorization Act of 2018, the Pilot Rest and Duty Rules ARC was formed to identify the effectiveness and deficiencies of the current Part 135 regulatory framework and develop recommendations for future rulemaking activities.
The ARC was comprised of a group of individuals that represented a cross-section of the charter industry and fatigue experts including government, industry organizations, operators, academia, and labor. Originally established in 2019, the primary objective of the ARC was to achieve the following as it relates to pilot rest and duty regulations: reduce the potential for excess fatigue across the complexity of Part 135 operations, provide a tiered approach for effective alertness management for a variety of business models, improve the enforcement of regulations, minimize the economic impact, accommodate the unique requirements of air medical services, and provide additional protections for flightcrew members operating during the window of circadian low (WOCL).
According to NBAA director of flight operations and regulations and member of the ARC Brian Koester, “The existing rules are based on preventing acute and cumulative fatigue. While they are based on science, fatigue science has advanced since the rules were written. Our goal was to use the opportunity presented by the ARC to recommend modern, performance-based regulations that reflect the advancements in fatigue science.”
In its report, the ARC identified several deficiencies in the rest and duty regulations and other dangerous practices that are common with some Part 135 operators.
Most apparent was an acknowledgment that the rules, first established in 1978, are applied equally around the clock and do not consider WOCL—a period where fatigue is at its highest level and alertness is low. WOCL is identified as a period between 0200-0600 (local for the pilots’ home base). Thus, the ARC recommended that regulations should account for the safety risks of increased fatigue during this period.
Other dangerous practices, as identified, include “rolling rest” and “Part 91 tail-end ferry flights.” Both practices hold the potential to induce fatigue and decrease safety margins.
Rolling rest is an “illegal and widespread practice of requiring a crew member to be in rest on a rolling (continuing) basis without assigning an end to the rest period.” Prospective rest periods—those with a defined beginning and end—are a better way to manage rest and, with new record-keeping requirements, will be more enforceable.
Part 91 tail-end ferry flights are another dangerous practice where operators require flightcrew to reposition an aircraft at the end of a Part 135 duty period. This practice was commonplace in helicopter air ambulance (HAA) operations until 2014 when regulations (FAR 135.601) were changed to define a Part 135 HAA flight to include those “conducted to reposition the helicopter after completing the patient or donor organ transport.”
Several Part 135 Pilot Rest and Duty Rules ARC members spoke with AIN about the prevalence of fatigue in Part 135 and other non-scheduled flight operations and about the ARC’s recommended new rules.
According to fatigue expert and Coalition of Airline Pilots Association (CAPA) representative Lauri Esposito, “Fatigue is a serious issue in nonscheduled flight operations because a pilot doesn’t always know when they are going to be operating a flight, which makes sleep management difficult. In other words, a pilot may know that he is ‘on call’ for a specific time period, but because he doesn’t know exactly when his flight assignment is during this timeframe, it is difficult to plan when to sleep.” Esposito, a Boeing 757/767 captain, also served on the Part 121 Pilot Rest and Duty ARC—these efforts and recommendations created a new set of regulations (Part 117) that are now applicable to all Part 121 passenger operators—cargo operators were exempt from these rules.
Jessica Naor, president of Grandview Aviation—a large charter operator—added, “Fatigue, particularly with Part 135 operators flying at night [during the WOCL], is a major problem in the industry. Many 135 operators on the ARC agreed that the current rest rules are not being followed, nor enforced because our current rules aren’t clear enough. Prospective rest requires that pilots are assigned specific rest periods and specific duty periods—on-call is not rest, yet many operators are leaving pilots ‘on-call’ or in ‘rolling rest,’ which has a huge impact on the alertness of crews flying in these environments.”
Naor expressed concern that the current rules are difficult to enforce; this creates a disadvantage for those operators that perform at a higher level of safety. “Operators following the rules can’t compete today either,” she said. “I have had charter brokers tell me personally they can’t use us because we have assigned rest periods for pilots—that was the day I realized how bad and how widespread this issue is. The industry can, and should, do better for our pilots and our passengers.”
Naor believes that taking a “safety first” approach to fatigue risk management was not only the right thing to do but may have some other intangible benefits such as pilot retention. “I feel strongly that when you make the right calls you will always be successful in the end. Beyond the safety aspect of this, we have better retention of pilots because they know we value them and we’re setting them up for success, not pushing them beyond their physical limits that could endanger them,” she said.
Quantifying the issue of fatigue in non-scheduled operations is difficult and the problem is more than likely under-reported, according to NetJets Association of Shared Aircraft Pilots (NJASAP) Industry Research Committee member Mike Hanson.
“Fatigue has long been an issue in Part 135 [and 91/91K] operations but quantifying that fatigue has always been a challenging task,” Hanson said. “Our Part 121 counterparts have benefited from mandatory safety reporting systems to help identify and mitigate safety-related issues [such as fatigue] for many years. However, Part 135 and Part 91/91K operators lag behind in the implementation of formal safety reporting systems, let alone the sharing of that data with other potential aviation stakeholders.”
A lack of a mandatory reporting system masks the true nature of the fatigue threat facing the industry, he continued. “Less than a quarter of Part 135 operators have a formal ASAP [reporting] program, and less than 10 percent of operators share quantifiable information with an organization such as ASIAS so that all aviation stakeholders can benefit.” Hanson has held various leadership positions at NJASAP and is a Cessna Citation XLS captain.
Hanson believes that fatigue is a major challenge for pilots flying for nonscheduled operators. “As a Part 135 pilot for a large operator, there are many issues that we face daily that can lead to acute and cumulative fatigue,” he said.
These issues include operating during the overnight hours, schedule flips (an early duty show time followed by a late duty show time, or vice versa), inconsistent duty start times, consecutive long duty days (up to 14 hours per duty day, no matter what time of day), an excessive number of consecutive duty days (with no current limit, outside of 13 days off per quarter), multiple changes to duty assignments during a duty day, no limit to the number of segments flown, long-range international operations, Part 91 ferry legs at the end of a Part 135 duty day, and hotel and transportation issues.
“Other operators and pilots may face additional challenges, depending on the type and schedule of their operations. Pilots that work for Part 135 scheduled operators face similar obstacles and challenges that pilots of Part 121 passenger carrying operators face, but without the fatigue protections of Part 121 or Part 117 rules.” Hanson added, “Additionally, some Part 135 operators incorrectly still use ‘rolling rest’ scheduling practices, and pilots may fear retribution if they were to call in ‘fatigued’ when they are too tired to safely operate an aircraft.”
Likewise, fatigue creates specific operational challenges ranging from routine business trips to complex aeromedical transport flights. “One of the key challenges we discussed on the ARC was organ transplant missions because this is one of the most fatiguing mission types in Part 135 today,” Grandview Aviation’s Naor said. “Grandview Aviation has been flying these missions since 2007 so we have a lot of experience and have felt the challenges of the existing rule set in this environment. Organ transplant flights happen with a couple hours’ notice during WOCL periods and the average mission lasts 10 hours. That’s very difficult to fit into a 14-hour pre-assigned shift without having many overlapping crew shifts to accommodate it, which most operators don’t have.”
Naor noted the ARC also identified the typical business meeting trip as being tough as well. “Pilots waking up in early morning hours to take off at 7 a.m. and fly back many hours later in the evening is grueling on crews but having a hotel room to grab a nap in would make a positive impact. Every table in the report is tied to some common circumstance that pilots in 135 fly and attempts to mitigate the fatigue risk associated with the timing and duration of the trips in cumulative hours, days, or time of day.”
FAA Has Fallen Behind
Hanson believes the FAA has fallen behind in implementing science-based rest and duty rules for charter operators, saying, “EASA, CASA, and the [Canada] ‘air charter’ Part 135 equivalents have all updated their rest and duty rules in recent years to reflect current scientific understanding of human physiology as it relates to fatigue. The U.S. regulations lag despite numerous attempts to bring our segment of the industry up to date.”
Efforts to change Part 135 rest and duty regulations began nearly 20 years ago; the first ARC was formed in 2003 with no action taken and additional efforts began in 2009. The 2009 Duty and Rest ARC was the basis for Part 117 rules, which were applied only to Part 121 passenger operations and ignored Part 121 cargo operations and Part 135 operations.
Hanson pointed out the irony because the FAA in its 2009 Rest and Duty ARC charter stated: “The FAA recognizes that the effects of fatigue are universal, and the profiles of operations occurring under parts 121 and 135 are similar enough that the same fatigue mitigations should be applied across operations for flightcrew members. To carry out the Administrator’s goal, the FAA is chartering an ARC that will develop recommendations regarding rulemaking on flight time limitations, duty period limits, and rest requirements for pilots in operations under Parts 121 and 135.”
Alertness Management Program
Recommendations from the Part 135 Pilot Rest and Duty ARC attempted to limit the overall economic impact while providing provisions for improved recordkeeping and rest scheduling. The report introduces the concept of an Alertness Management Program (AMP) and outlines a tiered solution that can accommodate operators ranging from a small charter operator with low-fatigue related risk to a more comprehensive set of rules for certificate holders more likely to be exposed to fatigue-inducing circumstances, including air medical and organ transport operators.
The purpose of an AMP is to promote flightcrew member alertness by providing fatigue monitoring and fatigue mitigations. The complexity of an AMP and the mitigations will depend on the type of operation. The ARC has recommended that the FAA publish an advisory circular on AMP.
Smaller operators that do not routinely operate during WOCL may opt not to employ an AMP. Rest and duty limits, in this case, are more restrictive to avoid the potential for unmitigated fatigue.
A Level 1 AMP, in general, has more prescriptive limits based on the number of pilots, and whether the duty period infringes on WOCL. As envisioned, the Level 1 AMP would allow additional flexibility and would be approved by the operator’s principal operations inspector.
A Level 2 AMP includes a customized set of flight, duty, and rest limits accompanied by an expanded AMP that defines the mitigations necessary for that operation. The requirements, as recommended, for a Level 2 AMP are much greater than a Level 1 AMP and would require approval from FAA headquarters.
The Part 135 Pilot Rest and Duty Rules ARC came to a consensus supporting the recommendations contained in the report submitted to the FAA. The proposed changes account for WOCL and other scientific principles to establish a more progressive set of rest and duty rules.
Transforming these recommendations into law is a long process, when asked if the industry is prepared for this change, the responses varied.
CAPA’s Esposito, who has personally witnessed major changes to rest and duty rules, maintained, “Yes, the industry is ready for these changes. FAR Part 117 was implemented in 2012. These scientifically based flight/duty regulations replaced FAR Part 121 for passenger carriers only. Initially, there was resistance from the airline industry, however, after more than a decade of operating under Part 117 none of the predicted detrimental impacts have come to fruition. The same thing will happen with Part 135. Both operators and pilots will adapt and adjust to the new rules.”
NJASAP’s Hanson added, “I think the industry is averse to change in general, but this is a known issue that needs to be addressed by all stakeholders involved: the regulator, the operators, and the pilots. The ARC membership discussed this at length, and while there will be an adjustment period, the recommendations will lead to a safer operation for the entire U.S. aviation system.”
Throughout the process, members of the ARC have remained focused on the primary issue of fatigue and its impact on safety, Hanson stated, adding: “And so it remains, fatigue has been common in our segment of the industry and continues to be to this day. Part 135 operations have greatly evolved over the decades, with aircraft that can cover all corners of the globe. Unfortunately, the only things that haven’t changed in that time is the human physiology that requires sleep to allow pilots to safely perform our duties, and the antiquated rest and duty rules that govern our operations. We are hopeful that the ARC recommendation document will be the basis for a long overdue NPRM that will finally update these rules.”
Grandview Aviation’s Naor further summed up why these efforts matter by saying, “Fatigue doesn’t typically get recorded as the primary cause of an accident, but we know that human factors is the biggest contributor to aviation accidents. Fatigue induces poor decision-making, mistakes, loss of concentration, and slowed reaction times, everything we know that causes accidents. The NTSB may not always name fatigue as the cause of an accident, but we can all understand intuitively that it plays a role in most accidents and incidents, particularly in cases where pilots are highly skilled.”