It happens even with the best of intentions- and among highly seasoned pilots and rookies alike – whether they are flying pistons- propjets- or jets. It also happens turning wrenches in a hangar- and in ATC tower cabs and Center positions: the insidious- sometimes deadly impact of fatigue.Back to Articles
First- in a scientific report that sampled corporate pilots promised anonymity- more than one in five said theyâd experienced fatigue issues when flying. A higher number admitted to nodding off in-flight.
Second- the reports revealed examples that didnât make news â but came uncomfortably closed to news-maker status. A real-life example follows (names- dates- locations and aircraft have been expunged):
A FAR 91 IFR flight flew along nicely in VMC- cruising well above a scattered layer of cotton-ball clouds with the flight-control system engaged. With nothing but the crisp blue skies of summer above- smooth air and a tailwind- the two pilots felt relaxed â too relaxed- as they soon discovered. With paperwork done and little else to do- Pilot Left Seat handed off the airplane to the qualified- current and (seemingly) alert Pilot Right Seat.
âIâm going to rest my eyes for a while-â Pilot Right told the now-PIC Pilot Left. âShake me in 20 minutes.â
A week of intense work at a well-regarded Business Aviation convention had preceded this flight. They had used their best judgment in an attempt to avoid the possibility of flying exhausted- and had even opted to spend a relaxed day off before flying home in recognition of their rest deficits.
On that final day they left the show hall at midday- napped- had dinner early with friends- and retired hours earlier than the norm of the prior six days â all of those 14- to 16-hour high-energy days. Both had slept later than usual â catching up on rest- they rationalized. Theyâd grabbed a light- late breakfast before heading to the airport at noon to make their planned 2pm departure that would assure a daylight arrival at their home field. And yet in spite of all of this- they nearly became news fodder!
With the lack of conversation or radio chatter- as the first pilot napped- the second pilot started to nod off; he fought off the unintended sleep a couple of times- awaking when his chin bounced off his chest. Finally he nodded out leaving âGeorgeâ- as they called the autopilot system- alone to control the aircraft.
The recognition of a distant- dreamlike voice repeating the aircraftâs call sign jolted Pilot Right awake; the controllerâs voice belied a sense of concern- even urgency. The controller sternly reminded Pilot Right to pay greater attention. The controller diverted traffic when neither crew acknowledged âseveralâ calls.
âWe should have stayed another day-â Pilot Right intoned as he elbowed awake Pilot Left. The time elapsed for this event: 15 minutes. The most-frightening aspect of this story? The crew opted to continue - talking- joking and still fighting fatigue through touchdown.
AN INSIDIOUS- SILENT THREAT
In recent years weâve seen several examples of fatigue seeping into the cockpit: a pilot over-flying a check point; a crew falling asleep in the cockpit and flying past their destination; a controller who napped in the ATC tower cab- unresponsive even to repeated phone calls from Center.
While falling asleep on duty may stand as the most-visible impact of fatigue- sleeping too little the night before isnât necessary for fatigue to work its devious way on pilots- controllers- mechanics and others. Fatigue accumulates- and rest deficits build up. Period.
No aspect of aviation enjoys an iota of immunity to the insidious- sinister and typically invisible effects of fatigue. Studies- research- real-world evidence all support this point. One research-based estimate put the percentage of fatigue-influenced accidents at 15 to 20 percent.
Within a couple of weeks of one another- two FAA controllers ânappedâ on duty- and one controller deliberately snoozed for five hours while operations at his airport continued without him. That occurred in February and made no ripples until after a tower controller at Washington National Airport nodded off and failed to wake up when Potomac Center rang his tower phone; two airline flights landed safely with clearances from Center.
But that incident made big news and started the FAA looking into whether other instances of on-duty controllers sleeping existed. They did.
Another big news-maker occurred just over three years ago when two pilots commanding an airline flight over-flew their destination by 30 miles. They fell asleep- unintentionally- simultaneously- and they only awoke thanks to alert flight attendants.
Personal stories from pilots bear similar characteristics to these events: disrupted sleep cycles for several days- sometimes everyday chronic sleep apnea. Combined with irregular work hours (leading to irregular sleep hours) and the complication issues of time-zone jumps- a pilot can suffer a serious deficit of restful sleep hours. Left unresolved the body-battery eventually drains down to nothing â and thatâs when body and brain start to wind down.
A common misconception is that extra sleep offsets the fatigue. The truth of the matter is that even a couple of days of ânormalâ sleep hours canât always rebalance the rest-time scales unbalanced by multiple long days- irregular hours and restless sleep cycles.
Corporate pilots endure all of the above issues. Even if they donât accumulate flight hours or flight cycles at the same rate- pilots flying business aircraft often put in days as long - or longer - than FAR 121 pilots; throw in the wider variability of airports and the need to tend to all the elements of a flight- and a corporate pilot can easily be preparing for the return of a four-day swing with an entire dayâs worth of lost rest working in the background.
HOW MUCH? HOW OFTEN?
According to safety authorities and investigators- many accidents and incidents involve fatigue as an element- if not as the primary factor. The number- they believe- would be higher if better tools existed to measure a pilotâs rest state before an accident. Often- determining fatigue as an element presents challenges unlike determining an obvious operational error or equipment issue.
Investigators typically work backward several days to reassemble the personâs state of rest at the start of an incident or accident event chain: when was wake-up; when did duty-time begin; how long was the day; when was bedtime; when was wake-up? One difficult aspect to measure involves determining the quality of sleep- or the effectiveness of the rest period. Typically pilots over-estimate their rest and under-estimate their fatigue.
Sometimes a medical factor unrecognized by the person comes into play. For example- one of the airline pilots who overshot their destination was found to suffer from severe- chronic sleep apnea - a major contributor to building a rest deficit.
Fatigue countermeasures expert Dr. Mark Rosekind founded- headed and served as chief scientist at Alertness Solutions. The company specializes in fatigue management in a wide range of safety sensitive- high-performance environments- aviation among them. Last year Dr. Rosekind accepted one of the five positions on the National Transportation Safety Board; many readers already know that fatigue management and methods for identifying fatigue is one the NTSBâs seven âMost Wantedâ safety recommendations to the FAA. To date- the board has rated FAA response as âUnacceptable.â
In presentations at multiple Bombardier Safety Standdowns- Dr. Rosekind noted apnea as a sleep-deficit contributor â along with other factors. Alcohol use- shifts in the rest cycle- age and even heritage are among the contributing factors. Genetics largely determine the amount of rest we typically need and how our bodies regulate their circadian rhythms â a cycle which may not mesh with a pilotâs work cycle.
Widespread as it is- fatigue impacts segments of aviation long subject to rules and regulations created to mitigate the problem. Commercial passenger operations under FAR 121 and 135 remain subject to flight-time/ duty-time rules for crewmembers; reports from the NTSB- strong anecdotal evidence- and the FAAâs current NPRM consider the existing rules insufficient to address the problem- however. While checks in the system tend to mask the imbalances- occasionally the issue resurfaces â as it did in Hawaii in 2008 and- more recently- in D.C. and Tennessee.
The FAAâs ongoing rulemaking process evoked intense criticism by air carriers and pilot groups alike (from the one side for overshoot- and from the other for coming up short). That debate will likely continue- as will interest among business operators using FAR 135.
Creating- applying and self-enforcing flight and rest policies is the norm for operators flying under FAR 91 operators- the rules under which most businesses operate their aircraft. The real-world examples listed above are tip-of-the-spinner examples.
SIGNS OF FATIGUE & COUNTERMEASURES
Youâve been called out for an O-Dark:30 departure; a client broke something and the support team are ready to shine â just as soon as the flight department shines and delivers them ASAP some three hours- and 1-100 miles away. Once there- the crew stands-by in case its needed further.
Hours pass- the support team members come straggling back in- looking to you to get them home to their beds. Itâs just 5 p.m.- but already youâve been up and moving 14 hours (18 by the time you get to home field). Whatâs more- this is the third time in five daysâ¦
Downing another coffee and grabbing a diet cola- you suddenly feel tiredâ¦ THAT should be the biggest signal you get that another crew needs to fly this return trip. Following is a rundown of the signs of impending fatigue:
â¢ Despite copious quantities of caffeine you just canât seem to get started.
â¢ Muscles feel sluggish and heavy.
â¢ You need a second to process the words of people talking to you (or re-read documents to comprehend them).
â¢ You keep hitting the replay button on the recorded weather briefing- writing down a little more each timeâ¦until done- when you look at your notes and canât decipher what they say.
â¢ You find yourself ravenous â until the food comes; then youâre not hungry.
â¢ You look back with pride when you realize youâve managed to get the equivalent of three days of good restful sleep â but then it hits you that it took you a whole five days to get that much sleep.
It shouldnât take a NASA scientist to tell you what NASA scientists already said. Listen to your body when it screams that itâs tired. Before the next trip- think about what you can do for yourself. Whether youâre a pilot- mechanic- controller or any other âroad warriorâ who regularly faces the struggles of fatigue- the following applies.
Limit caffeine use: If itâs good for a wake-up and short-term boost- use it. But itâs not a reliable all-day crutch. Limit use to before the mid-point of the day- or risk sleep disruption.
Limit alcohol use: A shot or a pint may prove refreshing to cap a long day- but alcohol is not a reliable- or safe sleep aid and can contribute to a less-than-restful sleep.
Develop a routine: What would pass for a routine in a business with few known routine days? Food control (some foods may make you sleepy- others perky) becomes part of that routine. Avoid the âkeeps-me-awakeâ meals or snacks- and try to avoid wide swings in your calorie intake. Hunger can be a significant sleep disrupter.
Move around: This doesnât need to be a trip to the gym- but do something other than sitting in the pilot lounge watching The Weather Channel or ESPN. Walk the ramp; walk the hangar rows; or climb the stairs a couple of timesâ¦youâll sleep better for starters.
Take a Nap (if possible): Take this at about the same time each day - even when out of the cockpit a couple of time-zones away.
Stretch en route: Walk around the cabin- hydrate and breathe pure O2 for a few minutes- which will prove a real booster. You can do all but the O2 anytime en route- but leave the O2 until about 15 minutes from starting the approach; itâs like a little elixir that boosts the brain and is particularly helpful at night- boosting your eyesâ color sensitivity.
Never climb into the cockpit (or let a crew member do so) when you know youâre already into a sleep-deficit situation. Getting an extra hour last night does not zero-out rest deprivation it took you days to build; so donât even think about it.
CORPORATE FLYING AND THE RESTED PILOT
In a survey conducted for NASA by Alertness Solutions- about two-thirds of corporate flight departments reported enforcing daily duty-time limits averaging just under 15 hours per day. Almost 99 percent - according to the survey - enforced no monthly or yearly limits.
Just over half had a policy limiting flight time to an average approaching 10 hours â and- again- no monthly or annual limits. Minimum rest cycle proscribed by the participating flight departments who had them (about 60 percent) came in at under 9.4 hours.
One in eight pilots responding said that past fatigue caused them to not fly a planned trip. A massive 71 percent admitted to nodding-off in the cockpit; 39 percent said they had arranged for the second pilot to be PIC while they napped.
Barely one in five said their flight departments offer training for recognizing- and dealing with fatigue. A large majority considered fatigue a problem unresolved. NASA published that survey in 2000. Awareness is much better today (in part- due to NASA- NTSB- FAA and the foibles of pilots and controllers).
Whether aviation (corporate- private or commercial) has a full handle on how to cope with- and combat fatigue remains an open question. Countermeasure programs exist. Pick one that matches your operations and work it as if your life depends on it. Fatigue clearly remains something to lose sleep over.