by Robert Matchette

"I had an 11.6 hour duty day with 8 legs. That night I had a reduced rest scheduled to exactly 8 hours. On the second day we were scheduled for 6.3 hours of duty with 5 legs. Both my F/O and myself awoke the next morning still feeling very fatigued and sleepy. On the last leg of the day, my F/O was flying as we were descending into the airport area for the approach. I fell asleep for about one minute and woke up so disoriented that for 500 feet I watched the altimeter unwind and wondered why we were climbing. This is not the first such incident. I have had altitude busts, missed checklist items, etc., following reduced rests." (ACN 203509)

• "Common in commuter flying are long duty days, multiple legs and low level IFR in very congested airspace...By the fourteenth hour and tenth leg of 200 [foot ceiling] and 1/2 [mile visibility] all day, with reduced rest ahead of you, neither pilot really gives a damn. Safe? Of course not. Everyday reality? Unfortunately, yes." (ACN 168469)

ASRS receives many reports from pilots of commuter aircraft alleging that fatigue induced by long duty schedules, compounded by inadequate rest, is often a primary factor in aviation safety incidents.[Endnote 1]

Major Carrier or Commuter?

Major air carriers and commuter operators tend to serve different segments of the air transport market. Major carriers usually operate larger aircraft over greater distances, while commuter carriers operate smaller aircraft over short, regional route structures with greater frequency of service. Each are governed by different provisions of the Federal Aviation Regulations (FARs). Part 121 of the FARs applies to aircraft of more than 30 seats operated in scheduled commercial air service, while in this review we examine FAR Part 135 as it applies to aircraft of 30 seats or less operated in scheduled commercial air service with two pilots.

Duty Time Requirements

Many of the rules and flight duty requirements differ between major air carriers (Part 121) and commuters (Part 135). Table 1 summarizes differences in the duty time requirements of these respective carriers.

Fatigue

Dr. R. Curtis Graeber [Endnote 2] summarized his findings on fatigue in air transport operations in the Proceedings of the Flight Safety Foundation 38th International Air Safety Seminar in 1985 as follows:

"An initial analysis of NASA's Aviation Safety Reporting System (ASRS) in 1980 revealed that 3.8 percent (77) of the 2006 air transport crew member error reports received since 1976 were directly associated with fatigue (Lyman and Orlady, 1980). This may seem like a rather small proportion, but as the authors emphasize, fatigue is frequently a personal experience. Thus, while one crew member may attribute an error to fatigue, another may attribute it to a more directly perceived cause such as inattention or a miscommunication. When all reports which mentioned factors directly or indirectly related to fatigue are included, the percentage increases to 21.1 percent (426). These incidents tended to occur more often between 00:00 and 06:00 [local time] and during the descent, approach or landing phases of flight. Furthermore, a large majority of the reports could be classified as substantive, potentially unsafe errors and not just minor events."

The Situation for Commuters

Why should there be any difference in the rules for major carriers and commuters? When Part 135 regulations were drafted, the equipment used in commuter operations was relatively slow and unsophisticated. Some of the equipment used in commuter operations is becoming more advanced, with commuters utilizing Electronic Flight Instrument Systems (EFIS), Traffic Alert and Collision Avoidance System (TCAS II) and autoflight equipment previously installed on larger turbojets. However, much of the equipment used by these commuter carriers is older-style technology, having primary navigation and instrumentation as compared to more advanced air carrier counterparts, and this often translates to a higher workload. In addition, aircraft having 19 or fewer passenger seats do not require flight attendants, further increasing the duties and workload of the crews operating them.

Commuter flight crews, unlike their Part 121 counterparts, often spend more of their flight time operating below 10,000 feet in busy terminal environments where there can be many changes to speed, altitude and heading assignments, such as New York, Los Angeles, San Francisco, Atlanta, Chicago, and Washington/Baltimore. To make matters more difficult, commuter aircraft may spend a greater percentage of flight time in instrument meteorological conditions (IMC) than turbojet equipment due to their lower cruising altitudes. These factors certainly aggravate the effects of acute and chronic fatigue. Consider the following pilot report:

• "...The entire day is scheduled for 7 hours and 20 minutes of flight time, which is a very unrealistic estimate when flying in and out of a New York hub, especially on an IFR day. Also, I believe someone should look into revising the maximum duty and flight time limits to include the amount of flight segments. Doing 10 ILS approaches to minimums and flying 7 hours is not the same as 1 round trip, New York to Denver, and doing 1, maybe 2 approaches and flying seven hours..." (ACN 176041)

A Sample Schedule

Below is a de-identified copy of an actual daily series of scheduled flights flown by a commuter carrier. To preserve anonymity, flight numbers and destinations have been removed (see Note 1). This trip was constructed in accordance with FAR 135.265. In this example, note that CITY B is one of the busy terminal environments discussed above, and the crew flies into AND out of this hub five times. (See Note 2.)

The crew flying this trip was to report for duty one hour prior to the first departure, and would remain on duty for fifteen minutes after arrival at CITY D at the completion of the last leg. It is important to note that delays during the day may become cumulative, so that completion of the trip may be much later than scheduled. The following graphic (Figure 1) summarizes the day's activities.

If this trip is flown as scheduled, 8 hours and 45 minutes is available for: 1) traveling to and from lodging, 2) eating evening and morning meals, and, 3) preparing for and arising from sleep. If transportation to and from lodging takes 30 minutes, and evening and morning meals can be consumed in one hour, and one hour is devoted to preparing for and arising from sleep, then only 6 hours and 15 minutes remain for sleep (assuming one can immediately drop off to sleep). Any delays in ground transportation or eating of meals will of course reduce the time available for sleep.

Changing Schedules

Unlike most 9-to-5 jobs, commuter airline schedules can change monthly, and within a given month, report for duty and off-duty times change as well. Such changes can reduce the amount of useful rest regardless of the length of layover, as this reporter notes:

• "Somehow we are supposed to shift from a morning to late schedule in 11 hours layover time...I never get more than 4 hours sleep, usually less...I hate to think how many accidents have occurred due to this type of scheduling." (ACN 92578)

Nightmares

The rest time between scheduled duty segments is of paramount concern to many commuter pilots. Writes one tired Captain:

• "I completed a minimum crew rest, and the next day my duty was 13:45 hours. Both my First Officer and myself are showing signs of fatigue. I am unable to concentrate, cannot repeat clearances back if they contain more than 2 bits of information, and I cannot even remember my flight number. I have fixation on simple tasks. I am going to take some time off without pay because these effects seem to be cumulative and intensifying each stressful day. Commonly, I have had to go 18 to 24 hours without eating. Attempts to ensure sleep needs and eating patterns is met with counseling and disciplinary action." (ACN 123033)

Standup Overnights

Another scheduling procedure used at regional carriers is known as the continuous duty or "stand-up" overnight. These schedules typically begin in the late evening hours and involve a one or two-leg flight from a hub city to an outlying destination where the crew remains on duty continuously throughout the night until returning to the hub city, sometimes at first light. While the crew is often supplied lodging, there is little time for sleep. As many as three of these stand-up overnights may be scheduled in consecutive days resulting in what some reporters describe as chronic fatigue. One reporter notes:

• "We were inbound to Atlanta on the MACY 1 Arrival at 11,000 feet about 60 miles out. ATC told us to cross 40 miles out at 9000 feet. The Captain was flying. I was the First Officer, working the radios. I read back the crossing restriction. The Captain dialed in 9000 feet in the altitude alerter. Both the Captain and myself simply forgot to descend. At about 38 DME, ATC asked us our assigned altitude. We then realized [that] we failed to descend. I read back our altitude and we descended immediately...A possible contributing factor could be the lack of adequate rest. We were finishing a continuous duty overnight and had 4 1/2 to 5 hours sleep the night before. This was my second continuous duty in a row." (ACN 200478)

The Captain of the same flight adds:

• "Was not able to sleep after going to bed. Got about 4 hours of sleep. Mentally, I was brain dead." (ACN 200735)

Another reporter describing an incident while on a continuous duty overnight claims:

• "...only 3 hours rest...the crew was very fatigued yet legal according to the FARs. I feel this kind of scheduling of stand-up overnight duty is an attack on safety. No one can maintain a high level of safety with only 3 to 5 hours rest at third shift. We [pilots] and the airlines should stop taking chances with people's lives." (ACN 175515)

A reporter admitting to falling asleep at the controls, adds:

• "I feel falling asleep at the controls or on duty has become almost commonplace, this is especially true on 8 leg days with 12 hours of duty or more. I also find this problem with so-called stand-up overnights. I believe these scheduling practices of 8 [or more] legs and stand-ups have made it almost impossible to be rested for maximum efficiency, safety and coherency. I feel this situation could be solved by outlawing stand-up overnights and increasing the required rest period. I also feel there should be a maximum number of takeoffs and landings, legs and trips that could be scheduled per month." (ACN 172229)

Quick Review

Let's review the problems many commuter pilot reported to the ASRS:

1. Commuter flight crews may experience greater workload because their aircraft are often less sophisticated than their Part 121 counterparts.
   
   
2. Flight schedules may have many legs, with pilots often returning again and again to high-density, high-workload airports.
   
   
3. Due to shorter trip segments and aircraft of lower performance, commuter flights are often required to operate IN the weather, not above it.
   
   
4. Commuter pilots often encounter duty schedules with minimum rest between duty periods.
   
   
5. Standup overnights and oft-changed schedules can lead to chronic fatigue due to sleep disruption and deprivation.

In spite of these operating conditions, commuter (FAR Part 135) flight crews have less restrictive duty schedule regulations than pilots for major air carriers. One reporter states:

• "The [FAR] 135 regulations do not protect the pilots flying at the commuter level in terms of rest and maximum hours flown per day. Pilots' decision making skills deteriorate at a much faster rate when flying the typical commuter environment (TCAs, high density traffic areas, approach and landing phase a majority of the time). If the regulations had a special clause for those operators who spend a majority of their time flying the approach/landing phase, then fatigue would be reduced considerably and the flying obviously safer..." (ACN 180664)

Looking for Solutions

One possible solution to the potential problems associated with fatigue in the commuter carriers could be to simply "cut and paste" the duty and rest requirements of part 121 into Part 135. Indeed, one senior FAA official has been quoted in Aviation Week & Space Technology [Endnote 3] as predicting "...a leveling, and it would be in an upward direction..." to improve duty schedule standards for FAR Part 135 carriers and pilots.

Recommendations

Notwithstanding possible changes to FAR Part 135 duty regulations, there are a few suggestions that can help reduce the impact of stress and fatigue-related problems faced by commuter pilots faced with demanding flight and duty schedules. In fact, these recommendations are good ones for all pilots.

Planning: For most of us, encountering the unexpected translates to increased stress, and increased stress results in increased fatigue. Many veteran pilots "mentally fly" their flights before showing up for duty, attempting to identify potential problems and possible solutions -- this can help reduce the stress of the unexpected.

CRM: Effective sharing of cockpit workload can also reduce stress and fatigue. Flight crews should review Crew Resource Management techniques before flight, and critique their performance afterwards to identify those areas where change or improvement is possible.

Rest: Getting adequate rest is difficult if a duty schedule calls for periods of reduced rest or stand-up overnights. It is recommended that pilots limit their activities and get adequate rest before reporting for difficult duty schedules. This can help reduce the impact of chronic (accumulated) fatigue.

Physical Fitness: Being physically fit will also reduce the impact of arduous duty schedules. It is recognized that moderate exercise reduces the effect of stress; taking a brisk walk (or some other form of exercise) after a long day, or between flight segments if time permits, means feeling better and sleeping better.

Nourishment: The benefits of proper and regular diet are well known, but many reporters to the ASRS note the difficulty in obtaining adequate nourishment during extended duty periods or following late arrivals. (Adequate nourishment doesn't mean a hamburger and coffee, either.) Millions of workers take lunch to work, so pilots with schedules that may preclude a good restaurant meal should do the same. Take a sandwich, and pack fruit and vegetables.