Know It All…Or Not

If I have to repair this in flight, something is beyond horribly wrong.

If I have to repair this in flight, something is beyond horribly wrong.

I punched a fist of joy into the air upon reading Bruce Landsberg’s recent editorial in the February 2014 AOPA Pilot magazine. He addressed the topic of useless knowledge being taught rather than critical overall concepts. I’ve been saying this very same thing for years, but since I don’t have a type rating in the Saturn V, I’m viewed as a dangerous menace to the national airspace system. Thankfully, his article lends credence to my stance that we often focus on useless data in aviation that is of little practical or emergency use. We should be looking at the big picture items with a lot more interest rather than the little details that only impress other pilots or examiners.

While I’d love to claim credit for being a maverick as it relates to the idea of not needing to know everything there is to know about an aircraft, NATOPS was leading the way with this mindset years ago. Anyone who has flown in the US Navy knows that the manuals for aircraft are purposely designed to exclude excess systems information. The only things that are included are things that the pilot either has control over, or any system that can cause a hazard to continued flight (and how that hazard will manifest). The reason is simple: mechanics fix airplanes and pilots fly them. This division of labor is present even in civilian aviation where the FAA makes it a point to tell pilots that save for a few preventative measures; they are not allowed to be a mechanic on their airplane.

I believe this focus on knowing every system in detail is a holdover from the good ole days of aviation (which we simply cannot move on from it seems). Systems were very complex and highly mechanical in nature. All of them were controlled by human beings, hence the plethora of people in the cockpit of vintage airliners. The flight engineer literally made sure all the systems operated the way they were supposed to. The pilots flew and if present, the navigator made sure they didn’t get lost. The crew had to understand their piece of the equation and at least a little bit of the other guy’s in order to pull off the flight.

Fast forward to today where the airplane’s flight engineer is the ECAM that collects and displays information about the status of every system several times per second. You literally don’t need to know much more from an operational standpoint for many systems other than “Is it on?”, “Is it off?”, and “Should it be in that state?” A friend of mine flies a Brazilian-built regional jet and has to memorize the starting and operating temps, abnormal shutdown criteria, and various RPM ranges…for the APU. Meanwhile, the only direct control over this device the pilots have is an Off-On-Start switch, a Stop switch and an emergency fuel shut-off switch (in the event of a fire, overspeed or overtemp, the APU FADEC will automatically command a shutdown). Does it make sense that three switches with a total of five possible selections warrants memorizing the type of compressor, every temperature limit, every RPM limit, and the type of cooling used by the APU?

While it may be interesting information to know, the role of a modern airline pilot is not to play mechanic. It is to fly the aircraft from Point A to Point B. If there is a problem with the aircraft, they write up what isn’t working and if it isn’t on the MEL, continue flying until it can get fixed by the maintenance guys. It’s not about being cavalier, it’s about being efficient with specialized skills. Ask yourself if there is any way for a motivated captain to crawl back to the tailcone in flight (there isn’t since the APU is surrounded by a firewall). Even if they could get back there, what could they do to fix a problem? Last time I checked, airlines don’t hand pilots toolkits with their Jepp revisions. What if more time in review and sim sessions was spent talking about things that are more likely to be encountered in day-to-day operations, rather than the specifics of a component that the pilot will most likely never even see and has limited control over?

Air France 447 is a perfect example of why broad scale knowledge is critical. An aircrew faced with a rare and confusing situation may be spring-loaded to go to a rather complex solution due to the way we train them. Ignoring the control input issues, had the crew been taught to look at the big picture of where is the information coming from, they might have considered the fact that the FMGS was likely showing correct groundspeed based off the GPS signals it automatically updates with. Additionally, the combination of pitch and power for a given flight condition would have led to suspicion that the EFIS PFD was at least partially lying (and thus to look for independent data, such as the FGMS). This is not an indictment of the crew, but a look at how a few seconds to consider the big picture before zeroing in on a smaller picture solution may prevent accidents like this from happening again.

The Air France accident was not the first time a high performance jet was lost at night in the vicinity of thunderstorms due to faulty instruments. A nearly identical situation occurred in a B-58 on February 14th, 1963 when the pitot tube iced up and the pilot began unknowingly following erroneous airspeed data. When the controls felt sloppy and he suspected something was wrong, the pilot cross-referenced with the Machmeter, but this was also giving an incorrect reading. It wasn’t until the pilot asked the navigator (who had an independent pitot system) what the airspeed was that he realized the delta-winged bomber was about to drop out of the sky. The aircraft ended up departing controlled flight and the crew members were forced to eject (see the article “B-58 Hustler” by Jan Tegler in the December 1999 issue of Flight Journal for the entire story). Hopefully with changes in training and multiple-source independent airdata, there won’t be any more accidents like these.

Aerodynamics is another place where we overthink things to the point that it might be causing poor decisions in some situations. My favorite horse to flog is the recent bank angle conservatism being taught in the United States. There is no magic law of aerodynamics that says if you bank 31 degrees at 999 feet AGL, your airplane will autorotate into a flat spin. Although the intentions are good, the source of this fear stems from the g-load charts that we all looked at as student pilots. In a 60 degree bank, load factor is doubled and stall speed increases substantially. The only problem is that this is only true if you attempt to maintain altitude. It is not even close to accurate in a descending turn. Nor is it accurate if one is flying an airplane with a lot of excess power/thrust. We have become so obsessed with the book numbers that the bigger picture of how aircraft actually fly in three dimensions is being lost.

Don't freak out if you hit 60 degrees of bank while descending.

Don’t freak out if you hit 60 degrees of bank while descending.

There are student pilots (and an increasing number of certified pilots) who will either fly C-5A sized patterns, or make skidding turns in order to keep the bank angle low. The former negates the engine-out glide advantage of a close pattern while the latter actually is a perfect setup for a spin. To be honest, a bank beyond roughly 30 degrees is not really necessary at speeds under 80 knots if the proper lateral spacing is used. The trap is when the pilot comes in a lot faster or much closer due to ATC request or their own misjudgment. All of a sudden as they notice they’re going wide, the rudder gets kicked in and opposite aileron starts to hold the bank angle constant. The saving grace is that usually this situation is created by having a surplus of airspeed so a spin isn’t likely provided they return to coordinated flight fairly quickly. Rather than worrying about a chart that isn’t applicable to their conditions, they should be taught the confidence to put the airplane where it needs to be to get where they want to go.

Again, before people get riled up, there is a time and a place for sticking to book numbers. Early 727 pilots who tried to eyeball the landings as if it was a DC-3 with jet engines learned about the importance of sticking to the book. But the book isn’t magic. The numbers it contains are the sum of the properties of the atmosphere plus the aircraft’s design plus the systems installed. If it takes the engines 9 seconds to spool from flight idle to “Oh crap” thrust, the obvious solution is to not be low and slow while at idle. You don’t need to know how many stages are in the low pressure compressor (six total, two fan and four compressor) to get the big picture of why you keep the power up on final. Knowing the big picture of how heavily loaded swept wings behave at high angles of attack will also give you a better understanding of why simply lowering the nose won’t immediately get you out of trouble (plus the delay in thrust buildup to further compound your woes). It is true that sticking to the book will ensure that you arrive safely, but it is better to understand both the concept and the details.

Pilots cannot and should not know it all. The FAA regulation to “Familiarize yourself with all available information concerning that flight” is a rule designed so that if a pilot makes any error that “reckless and careless” doesn’t cover, the book can still be thrown at them. Rest assured that if you put one into the ground a half-mile short, you’re getting blamed for not getting a weather briefing despite it being CAVU with calm winds, flying an aircraft with an inoperative ADF and for not knowing the airport manager’s office phone number . This is a poor way to ensure safety but a great way to have instant blame in the event of an incident. Instead of scaring pilots into trying to read everything to fit some liability model, we should be encouraging them to select the appropriate data for what they want to do.

We collectively have to accept that despite what we would like to have everyone believe, 99.2% of pilots will never know every single little detail about their airplane. This should be instilled in student pilots via the way they are taught. Start with the basics and allow them to get used to the 3rd dimension. Instead of filling their heads with regulations from day one, ease off and let them enjoy flying. Let them have a few hours of wrapping their heads around controlling the airplane before revealing that they’re going to have to become a lawyer as well to understand all the regulations. Instructors can easily move from the big picture of “Let’s do our maneuvers up high so if you make a mistake we have plenty of room.” to the verbatim description of FAR 91.303 over the course of their training. The rules will make more sense anyway if a little bit of experience and common sense are applied rather than “you need to know this for the test”.

As usual, I’m sure not many people will read this (especially this far down) and those that do think I’m either full of myself, dangerous, a crusader or a combination of the three. The truth is I love aviation but I’m also willing to point to where we can do a better job making it less daunting for newcomers to get involved, safer for those already flying and more enjoyable for everyone. If we are honest, it’s time to admit that the act of flying is not very difficult in execution. Judgment on the other hand is what kills people. Being able to recite regulations does not stop people from flying into IMC or descending below minimums. Only the proper attitude and respect for the fact that you’re suspended in the air by the laws of physics and aerodynamics will make a person accept their own limits and those of their aircraft. This must be stressed more than any chart, schematic or diagram.

BMI Tests For Pilots: Avoiding The Issue

(This article was originally published on my fitness site www.liftlazy.com but due to its inherent focus on aviation, I’ve posted it here as well)

 

The proposed addition of neck circumference and BMI testing to the airman’s medical exam is inaccurate, misguided and of limited usefulness. The impetus behind this screening is the recent spate of tired pilots making mistakes and even falling asleep while on duty. In one such incident it was later revealed that the captain had sleep apnea which was viewed as a probable cause for his falling asleep enroute (since sleep apnea is not contagious, the reason for the first officer also falling asleep at the same time was chalked up to fatigue). While this change to the medical exam affects all pilots, including those who fly privately, this piece will focus on air carrier pilots.

Aviation is under a constant media microscope and these incidents while statistically miniscule, nevertheless raise the suspicion of the public. Falling asleep at a job as hazardous as those that exist in aviation should not be tolerated, but using a questionable screening process should not be accepted in an attempt to create a solution to a condition that may or may not exist and most likely is not the primary cause of exhausted pilots. For the record, each year there are over 100,000 motor vehicle accidents that are attributed to drowsy driving. Despite the loss of 1,500 lives, so far no public safety department has mandated obesity or sleep apnea tests for motor vehicle drivers, even commercial operators.

Body Mass Index Accuracy

It has been proven that people with extremely high body fat percentages are susceptible to obstructive sleep apnea. It has also been proven that sleep apnea causes both hypersomnia and insomnia, impairs cognitive function and can lead to cardiac arrest in extreme cases. These facts are also not in question. What is troubling is the method being used to determine this risk factor in pilots, namely, the BMI rating.

BMI, or body mass index is a handy method for calculating a person’s mass to height ratio. As such, it is useful as a quick evaluation concerning obesity. The problem with BMI is that it is a very “dumb” equation; it does not know what it is measuring. A “smart” doctor, trainer, or clinician has to interpret the number and take into account other physiological factors (even the CDC states that BMI is not a diagnostic tool). Unfortunately, because BMI requires no specialized equipment or tactile measurements on the patient, it is widely used by people who have limited knowledge about the human body, obesity, bone density or muscle mass. This results in gross misinterpretations and misdiagnosis for people of various body types.

Another problem with BMI is that it leaves out critical factors such as age, gender, and body fat percentage. As people age, they naturally lose muscle mass unless steps are taken to preserve it (such as lifting weights). The loss of muscle mass, while detrimental, will show up as a reduction in BMI, leading the patient to think that they are getting healthier. Women on average have less muscle mass than men, resulting in more women being classified as healthy and more men as obese, even if the opposite is true. And most tellingly, if a person is 5’8” and 190lbs with 8% body fat, they will score the same BMI as someone who is 5’8”, 190lbs and 30% body fat (it is the same logic as saying that a Ford F-150 and a Ford Mustang will perform exactly the same since they have the same horsepower). One would think that scenarios such as these would be easily noticed and accounted for, however that does not appear to be the case in several well publicized instances.

In recent months, stories have come out where middle schools with good intentions unwittingly labeled some student athletes as “at risk” or obese based on a BMI calculation. The fact that nobody in charge of the program even understood how to deal with off-scale errors caused by a student having more muscle mass than their peers is distressing. Part of this rampant misinterpretation stems from our nation’s obsession with weight as the be-all-end-all indicator of a person’s health. Weight alone is a useless metric. It merely tells us how much of an effect gravity has on a given person. It does not tell us the distribution of body fat or muscle mass, which are the critical values that directly affect a person’s well-being. And as previously mentioned, simply possessing the stats of being 5’8” and 190 lbs only means that you are 5’8” tall and 190 lbs. Any other inferences must be determined by checking body composition.

As angry as the students and parents were at this mislabeling, imagine if your job relied on BMI numbers that may not have any basis in reality. It has been shown that it is very easy to make sweeping generalizations based on spurious data and then pass off any errors as anomalies. Will an airline ignore high BMI numbers in a visibly fit pilot, or will they tell them to atrophy away some muscle mass in order to lose weight? Alarms should be going off in the head of every pilot in America. If it can happen to children in school, it can and is about to happen to them as well.

Flight Fatigue

The cockpit of a modern jetliner can be a very sleepy place physiologically speaking. Noise fatigue from the slipstream roaring past the windows (a very effective white noise generator), reduced oxygen levels even with a pressurized cabin, and the inability to simply stand up and walk around are just some of the fatigue inducing factors present. Any one of these factors by themselves are hazardous enough to have volumes written about their attendant risks. Somehow, they are not even mentioned as a possible factor in pilot fatigue in this new screening process.

In fact it is entirely possible that it is an attempt to divert attention away from the fact that the new rest rules enacted by the Federal Aviation Administration have not fully accomplished their goal of eliminating pilot fatigue. This is only because airlines are not required to fully implement these rules until the end of 2013. Federal regulations now allow air carrier pilots a maximum of 9 hours of flight time and at least 10 hours of rest per each 24 hour period. To those who don’t fly for a living, a 9 hour workday does not sound that difficult and 10 hours of rest seems like it should be adequate. In reality flight time only accounts for loggable time in the aircraft (in airliners, the parking brake serves as the aviation equivalent of a time clock).

The new rules do a much better job of eliminating fatigue due to deadhead commuting and excessive duty times. Preflighting, checking weather, waiting for ground stops to expire, briefing, and all other tasks directly associated with preparing to fly an aircraft are limited to no more than 14 hours per day. Unfortunately, traveling to the airport, leaving the airport and checking into hotels all accounts for time that is not yet definable by the FAA.

Confusion abounds in the general public as to how a pilot halfway through a 3 hour flight can fall asleep. While that one flight is only three hours, it may be the second flight that day on the third day of a four day trip away from home. Anyone who works 9 to 14 hours is going to be tired. Anyone who works 9 to 14 hours going back and forth between time zones, sleeping in unfamiliar beds, unable to establish a consistent exercise regimen and not having access to healthy, agreeable foods is going to be even more tired. Now ask that person to stay alert in an environment that is almost custom built to induce sleep for four days in a row. This is the real reason why pilots are tired, make mistakes and fall asleep. When two pilots fall asleep and overfly their destination, or when critical mistakes are made due to fatigue induced cognitive impairment, the last thing that should be looked at is sleep apnea. Is sleep apnea a risk? Absolutely, but in the long list of causal factors it is not anywhere near the top.

The combination of desire to generate profit, maintain public confidence in aviation and ensure pilots are not forced into unhealthy patterns is a difficult river to navigate. The FAA has tried to close a massive loophole in their prior regulations via their current definition of Flight Duty Period. Airlines have historically exploited this oversight and were against changes to the Flight Duty Period limits (see page 112). Currently the issue is that duty time ends once the aircraft is parked, not when the pilot arrives at the hotel (we are assuming the pilot is in the middle of a multiple-day trip and cannot simply go home). It can easily take an hour to go from the cockpit to a hotel room, sometimes more. Assuming the pilot eats immediately, that leaves roughly 30 minutes before they are supposed to be sound asleep in order to take advantage of the “8 hour uninterrupted sleep opportunity”. In the morning, the reverse is in effect as it takes a similar amount of time to get to the airport and check in at the crew room. It is easy to see how the 8 hours of sleep can quickly erode to 6 or less. As a good friend who flies for a major air carrier said, “The new rest rules need to address the fact that we can’t go to sleep while making the first turnoff, nor can we wake up at V1.”

Instead of neck circumference and BMI tests,  there should be demands for better scheduling practices for all air carriers. Require that pilots get up and walk around the cabin for a couple minutes every hour (security rules be damned). Mandate that pilots take a few breaths from their O2 masks whenever they feel tired. Implore the FAA to close the final loophole in the definition of Flight Duty Period. Consolidate preflight tasks or delegate them to a dedicated ground crew much like military does with its crew chiefs. Install better soundproofing insulation in cockpits to reduce noise fatigue and hearing loss. Encourage airlines to create dedicated “pilot apartments” at their bases to eliminate travel time for the crews. Any one of these potential solutions solves multiple major issues facing pilot workplace health, which is the most effective way of mitigating the fatigue issue.

Conclusion

Should obesity screening be conducted? Considering that airline pilots must possess a 1st class medical certificate which can only be obtained after a battery of tests including an EKG, it seems odd that severely obese pilots are just walking around by the thousands. Many aircraft are tough to fit into even for an average sized person, so there’s yet another barrier to the truly obese sitting in the cockpit. But for the sake of argument, let’s say that there is a sizable population of obese pilots. There are far more accurate methods of determining levels of adipose tissue distribution than a distorted height to weight ratio. Aerospace Medical Examiners are certainly intelligent enough to use methods such as caliper skinfold or bioelectric impedance to make the necessary measurements. Then that physician can make recommendations on what the pilot can do to reduce their body fat percentage. Focusing on body fat, not weight, will have a far more effective result on the pilot’s overall health than zeroing in on one potential condition.

Flying aircraft is mentally and physically taxing. Pilots are still just mere mortals who have the same body the rest of us have. It requires food, exercise and sleep or it will not function optimally. To expect them to operate like machines is not realistic. Airlines need to accept this, the FAA has to continue to support this and pilots themselves have to live with this. Until it is determined that fixing the underlying causes is worth the cost, we will continue to see more pilots making fatigue induced errors and overflying destinations while fast asleep.

Suggested Further Reading

Center For Disease Control: “About BMI For Adults
Sept 13, 2011
 
FAA: “New Obstructive Sleep Apnea Policy” ; Fred Tilton MD
November, 2013
 
Mayo Clinic: “Sleep Apnea
July 24, 2011
 
FAA: “Fact Sheet – Pilot Flight Time, Rest and Fatigue
January 27, 2010
 
FAA: “Flightcrew Member Duty and Rest Requirements
December 21, 2011
 
The Sleep Foundation: “Sleep Studies
 
National Institutes Of Health: “Neck Circumference And Other Clinical Features In The Diagnosis Of Obstructive Sleep Apnea Syndrome” ; Robert J.O. Davies, Nabeel J. Ali and John R. Stradling
October 24, 1991
 
NHTSA: “Drowsy Driving And Automobile Crashes” ; Kingman P. Strohl MD, et al
 
International Journal Of Obesity: “Accuracy Of Body Mass Index In Diagnosing Obesity In The Adult General Population”; A. Romero-Corral, et al
February 19, 2008
 
FlightPhysical.com: “Summary Of Pilot Medical Standards
February 26, 2007