Posts Tagged ‘safety’

See & Avoid Doesn’t Work

Tuesday, November 10th, 2015

Contemplate the worst scenario that might confront a pilot during a flight. What comes to mind? Fire? Flight control failure? Engine failure? Perhaps it’s flight crew incapacitation, explosive decompression or severe structural damage.

No doubt about it, those all fall into the Very Bad Day category. But there’s one that can be even worse: a mid-air collision. That’s because it can involve all the problems listed above — at the same time. And since the parties involved aren’t aware of the impending crunch until it’s too late, the mid-air is usually accompanied by a violent element of surprise, confusion, and initial denial.

You might think fatal mid-airs are rare events, and from a purely statistical standpoint I’d have to agree. According to the 2010 Nall Report, a fatal mid-air occurs about once every 8 million flight hours. Think of it as the roughly the same odds as winning the lottery or being struck by lighting. Doesn’t sound so bad, does it? A typical GA pilot might accumulate but thousand or so hours over a full lifetime of flying.

So what’s there to worry about? Plenty. The “big sky” theory may sound good, but it doesn’t hold up very well under close scrutiny. It’s true that the navigable atmosphere over the United States alone is massive — about 20 million cubic miles — and there are relatively few airplanes in the sky. Even on those occasions where a collision is possible, modern tools such as radar, TCAS, VHF communication, and anywhere between two and four sets of eyeballs almost always succeed in averting the disaster. If aircraft were equally distributed throughout the atmosphere, the “big sky” idea would be pretty comforting.

But airplanes cluster near airports, large cities, and on thin slices of the sky known as “airways”. For the VFR types, airspace and terrain often crowd planes into small swaths of the air in places like the Santa Ana Canyon or Banning Pass. The sky is much like the ground: vehicles stick to relatively confined spaces and that makes collisions a serious hazard.

Since we’re on the topic of statistics, let me give you a few of my own: I personally know two people who have been struck by lightning, and a winning lottery ticket was recently sold not 300 feet from my front door. Hey, crazy stuff happens. But unlike lighting strikes and golden tickets, we’re not all facing the same odds. The risk profile varies widely depending on the type of flying you’re doing.

For example, flight instruction is frequently a factor; thirty-seven percent of mid-airs occur with a CFI on board. Many instructional flights happen near airports, and as previously mentioned, that’s where other airplanes tend to congregate. On the other hand, if you fly airliners, your risk of a mid-air is rather low because the aircraft itself is large and easy to see, you’re always flying IFR, and the most sophisticated traffic avoidance hardware available is always installed. Airliners also spend most of their time in cruise and are in constant radar contact with ATC.

Midair collisions are almost as old as powered flight itself.  This B-17 collided with a German fighter over Tunisia in 1943.

Midair collisions are almost as old as powered flight itself. This B-17 collided with a German fighter over Tunisia in 1943.

Think it can’t happen to you? Think again. Some very talented, capable, and well-respected pilots have been involved in mid-air collisions. I know a guy who was involved in one while flying a large-cabin, TCAS-equipped business jet under Instrument Flight Rules. Alan Klapmeier, the founder of Cirrus Aircraft, was in one too. Richard Collins, famed Flying columnist, was in a mid-air. Speaking of Flying, the recent Editor-in-Chief owns a very nice Cirrus SR-22 which was in a mid-air. And lastly, a decade ago I was in a mid-air collision myself.

I’ll save the blow-by-blow (no pun intended) on that for another day. The point I’m trying to make is that the odds of a mid-air are probably greater than you think, especially if you live in a populated metropolitan area and fly VFR. If you’ve ever had a close encounter with another airplane in flight, you were only separated from “those who have” by nothing more than a miniscule sliver of plain old luck.

Think about that for a moment.

This may be hard to believe, but there is some good news. For one thing, mid-airs are not always fatal. It seems intuitive that most collisions would involve fatalities, but all the people I cited above survived, including (obviously) myself. Also, technology is rapidly advancing, from cheap TCAD boxes to airframe parachutes to super-bright LED exterior lighting.

The question we should all be asking ourselves is how we avoid ending up in a mid-air, fatal or otherwise. If you refer to official guidance from the FAA, the answer is to simply look out the window and spot the other airplane before it hits you. This technique, referred to as “see and avoid”, is still considered adequate for preventing collisions. Here are a couple of passages from Chapter 1 of the Airplane Flying Handbook:

The “See and Avoid” concept relies on knowledge of the limitations of the human eye, and the use of proper visual scanning techniques to help compensate for these limitations. The importance of, and the proper techniques for, visual scanning should be taught to a student pilot at the very beginning of flight training.

Proper clearing procedures, combined with proper visual scanning techniques, are the most
effective strategy for collision avoidance.

Other FAA publications, ranging from the Aeronautical Information Manual, to Advisory Circulars like AC-90-48 (“Pilot’s Role in Collision Avoidance”) will give you the same spiel: “see and avoid will keep you safe”. And it will! Until it doesn’t.

From my perspective as someone who’s been in a mid-air and who was using proper clearing and scanning techniques at the time, I take it as gospel that “see & avoid” won’t always do the trick. I’m just one guy, of course. But many others — some institutional in nature — just happen to agree with me.

For example, a couple of years ago Canada’s Transportation Safety Board issued an accident report on a mid-air collision between a Beech V-35B Bonanza and a PA-28 Cherokee over northern Virginia. Canada was tasked with performing the investigation because the pilots of the Bonanza were employees of the NTSB while the Cherokee was piloted by an employee of the FAA.

I won’t keep you in suspense. The conclusion from the TSB was that the “see and avoid” concept was inadequate. They even quoted a 1991 report produced by the Australian Transport Safety Bureau which provides an overview of the major factors that limit the effectiveness of the see-and-avoid principle in preventing mid-air collisions, as well as a 2005 scientific study published in Aviation, Space, and Environmental Medicine which came to the same conclusions.

The main points:

  • Cockpit workload and other factors reduce the time that pilots spend in traffic scans, and even when pilots are looking out, there is no guarantee that other aircraft will be sighted.
  • Visual scanning involves moving the eyes in order to bring successive areas of the visual field onto the small area of sharp vision in the center of the eye. The process is frequently unsystematic and may leave large areas of the field of view unsearched.
  • A thorough, systematic search is not a solution as in most cases it would take an impractical amount of time.
  • The physical limitations of the human eye are such that even the most careful search does not guarantee that traffic will be sighted.
  • The pilot’s functional visual field contracts under conditions of stress or increased workload. The resulting ‘tunnel vision’ reduces the chance that an approaching aircraft will be seen in peripheral vision.
  • The human visual system is better at detecting moving targets than stationary targets, yet in most cases, an aircraft on a collision course appears as a stationary target in the pilot’s visual field.
  • An approaching aircraft, in many cases, presents a very small visual angle until a short time before impact.
  • Complex backgrounds such as ground features or clouds hamper the identification of aircraft via a visual effect known as ‘contour interaction’. This occurs when background contours interact with the form of the aircraft, producing a less distinct image.
  • Even when an approaching aircraft has been sighted, there is no guarantee that evasive action will be successful.
  • Because of its many limitations, the see-and-avoid concept should not be expected to fulfill a significant role in future air traffic systems.
  • Transportation Safety Board of Canada aviation investigation report A06O0206 identified that there is a high risk of mid-air collisions in congested airspace when aircraft are not alerted to the presence of other aircraft and rely solely on the see‑and-avoid principle.

There’s one more area of the TSB report which is worth of quotation. In it, they reference a British Royal Air Force study into mid-air collisions. If you’re keeping score, that’s the third sovereign agency to reach the conclusion that “see and avoid” is inadequate. Yet our own FAA, which oversees about 80% of the world’s aircraft and almost all of the high traffic density airspace, still officially proclaims that one can look out the window and see everything that needs to be seen.

This accident has demonstrated yet again that relying solely on the see-and-avoid principle to avoid collisions between aircraft operating under visual flight rules (VFR) in congested airspace is inadequate.

A number of international studies have addressed the overall issue of the effectiveness of the see-and-avoid principle, as well as the risks of collision associated with this principle. All acknowledged the underlying physiological limitations at play and that, when mid-air collisions occur, “failure to see-and-avoid is due almost entirely to the failure to see.”

One study stated that “our data suggest that the relatively low (though unacceptable) rate of mid-air collisions in general aviation aircraft not equipped with TCAS [traffic alert and collision avoidance system] is as much a function of the ‘big sky’ as it is of effective visual scanning.”

A British Royal Air Force study into mid-air collisions, which were deemed to be random, found that the probability of conflict is proportional to the square of the traffic density, and recommended avoiding altitude restrictions that concentrate traffic.

Measures such as improving aircraft conspicuity, pilot scanning techniques, and pilot traffic awareness can reduce risks, but they do not overcome the underlying physiological limitations that create the residual risk associated with a see-and-avoid method.

It’s obvious that “see and avoid” cannot, by itself, ensure our safety. If it could, there’d be no need for TCAS or most of our controlled airspace (both of which came about because of high-profile mid-air collisions, I might add!). I’m not necessarily in favor of mandating any additional equipment, airspace, or restrictions, especially on general aviation. But it’s clear that serious changes are needed in how collision avoidance is taught, especially as it concerns “see and avoid”. The concept has serious limitations which must be understood so the pilot-in-command can make educated decisions about how — or even if — they want to mitigate those risks.

I sincerely hope our nation’s regulatory and safety organizations will eventually acknowledge what we all know to be true: “see and avoid”, while a good start and certainly a vital part of collision avoidance, is simply not sufficient to ensure traffic separation.

Perspectives on GA safety

Tuesday, September 8th, 2015

Well, it’s that time of year again: as summertime recedes in the rear-view mirror, I’m packing my computer bag, a few snacks to eat on the (Air)bus, and heading back to school.

In case you’re wondering, yes, I did graduate from high school. And college, believe it or not — I’ve got the diploma to prove it! No, this late summer tradition is my annual trip to Dallas for recurrent training on the G-IV: five days of classroom learning and simulator sessions, ending with a formal checkride.

One of the questions typically asked by the instructor on our first day of class is if anyone has experienced anything in the previous year which was particularly noteworthy or unusual. A system failure, something of that nature. I’ve been pretty fortunate; the company I fly for does a bang-up job maintaining the fleet.

But while mentally reviewing the past year’s trips, my mind drifted off to the place where my heart truly belongs: light general aviation flying. Maybe it’s because the latest Joseph T. Nall Report was recently released by AOPA’s Air Safety Institute. Anyway, I don’t mind admitting a bit of wistfulness that GA can’t claim the same safety record that air carriers — even non-scheduled ones like mine that fly all over the world at a moment’s notice — enjoy.

Nevertheless, in an odd way I take comfort in the fact that the Part 91 safety record isn’t as good. That probably sounds awful, but look at it from a logical standpoint: Part 121/135 represent very specific kinds of highly structured and limited flying, whereas “GA” represents everything from airshow acts and experimental aviation to medevac and ultralights. It covers a wide and vibrant variety of aviation activity.

GA has a higher accident rate than the airlines for many reasons, but the primary one is that GA pilots have the freedom to do many things that the airline guys do not. And I hope that never changes. To paraphrase Dick Rutan, where would we be without those who were willing to risk life and limb using their freedom to do these things? We’d be safe and sound, on the ground, still headed west as we look out over the rump of oxen from our covered wagons.

Whether it’s cruising down the coast at 500′ enjoying the view, taking an aerobatic flight, flying formation, flight testing an experimental airplane, or landing on a sandbar, beach, grass strip, or back-country field, it’s important that private individuals not find themselves restricted to the ways and means of Part 121 operations. We do the stuff that makes flying fun! Doing it “like the airlines” can only drive up the price and suck out the fun of aviation. For better or worse, part of that cost is in increased risk.

Richard Collins stated this quite elegantly when he said, “Lumping general aviation safety together is an accepted practice but it is not realistic. The activities are too diverse and need to be considered separately. There is instructional flying, recreational flying, agricultural flying, private air transportation flying and professional flying. The airplanes range from ultralights to intercontinental jets. Even in the same area, different airplanes have varying accident rates. The only safety concern that spans everything is crashing but the frequency of and reasons for the crashing vary widely according to the type flying and even the type aircraft flown. In each area, the safety record we get is a product of the rules, the pilots involved, the airplanes, and the environment in which the pilots fly those airplanes. To make any change in the record, one or all those elements would have to be modified.”

I don’t always see eye-to-eye with Collins, but this is a case where we are in violent agreement. One of the beauties of our Part 91 is that the pilot gets the freedom to choose how far he wants to go in that regard. If you want to file IFR everywhere and only fly with multiple turbine engines in day VMC, fine. That’s your choice. For others, flying in the mountain canyons in a single-engine piston and landing on a short one-way strip on the side of a steep hill is well within their risk tolerance. There are some (I’m looking at you, Team Aerodynamix) for whom a large group of owner-built airplanes flying low-altitude formation aerobatics at night is perfectly acceptable. Whether we are personally engaged in that activity or not, how can one argue that these activities don’t benefit the entire GA community? What excitement and passion they engender for aviation! And how they set us apart from the rest of the world, who for the most part look on with envy at something they will never be “allowed” to do.

Don’t get me wrong. I’m certainly not opposed to better equipment, more training, or higher standards for general aviation. Those things are all important, and I advocate for them constantly. But if experience has taught us anything, it’s that these measures will only be effective when they come from within rather than being imposed from a bureaucracy which already demands so much.

NOTAMs: A Lousy System

Monday, July 6th, 2015

One of the dirty little secrets about general aviation is that you can spend as much time preparing for a flight as you do actually flying. It’s not something we’re keen to talk about when discussing the amazing efficiency of traveling by GA, but sooner or later every pilot discovers that flying isn’t always faster than driving. Sometimes it’s a lot slower.

What got me thinking about this was a series of short-range trips I’ve made recently in the Gulfstream: Los Angeles to Phoenix, San Jose, Las Vegas, Fresno, and so on. You’d think it logical that a shorter flight would mean a more effortless work day – but it ain’t necessarily so. The tasks required for a short flight are exactly the same as those needed for a longer one. Filing a flight plan, generating weight & balance data, checking weather, and pre-flighting the aircraft aren’t appreciably faster for a 500 mile leg than a 5,000 mile one.

In fact, once we takeoff, the “hard” work is mostly done and the more congenial, relaxing portions of the trip begin. This is often true for small very airplanes. One might even say “especially” for small aircraft. A flight in the Pitts, for example, averages about 30 minutes, but I can’t imagine completing pre-flight tasks and getting off the ground in less time, especially when there’s a passenger involved. Just getting someone properly briefed and fitted into their seat and parachute can take a considerable amount of time.

The point is, preflight activities are vital to safety in the skies and we can’t shortcut them. Or can we?

The law — 14 CFR 91.103, specifically — requires pilots to obtain “all available information” about a flight before departure. That’s a pretty broad mandate, especially in the Information Age. But it makes sense, because while aviation may be a relatively safe activity, it’s not terribly forgiving of carelessness.

For a typical flight, “all available information” includes NOTAMs, something I’ve found to be a major time suck. While the Feds have made minor changes to the NOTAM setup in recent years, from my perspective it’s still a truly lousy system. It pains me to say that, because the FAA gets some things very, very right. This isn’t one of them.

As Sen. James Inhofe found out a few years ago, the price of missing a NOTAM can be steep. Bringing these notices into the 21st century would greatly improve flight safety and do so at a relatively low cost. If nothing else, it would encourage more pilots to actually read them! It’s difficult to fault pilots for glossing over data when it looks like this:

!JFK 06/204 JFK RWY 13R/31L SE 3263FT CLSD. RWY 13R TORA 10672FT TODA 10672FT ASDA 10672FT LDA 8629FT. RWY 31L TORA 10924FT TODA 10924FT ASDA 10924FT LDA 11248FT. 1506251331-1509211600

Should flight information look like something off a 1950’s teletype or a badly formatted excerpt of assembly language? I’m tempted to say “if we can put a man on the moon…” – you know how the rest of that goes. But perhaps it would be better to simply ask that, in the midst of spending untold billions on NextGen, a few paltry dollars be allocated to overhauling our ghastly NOTAM system.

I know that building a better mousetrap is possible because I’ve been using one for more than a decade. Dan Checkoway, a longtime friend and fellow pilot, saw the same deficiencies in preflight information delivery. But he did something about it, developing a site called Weathermeister. Among other things, it translates NOTAMs into plain English, adjusts the valid times to a more readable format, and best of all, color codes critical items like runway and airport closures so they stand out.


The difference is dramatic. Not only can I scan NOTAMs far more quickly, but I’m also less likely to overlook something important. On several occasions I’ve been the one to unearth important NOTAMs that a fellow crewmember missed. Does that make me superior aviator? No… just a guy with a better sledgehammer.

Dan once told me that despite the fact that Weathermeister provides full weather briefings, 90% of the site’s coding is dedicated to translating the arcane NOTAM texts into readable English. He once tried to sell the FAA on using his format, but for whatever reason (bureaucratic inertia, perhaps?), nothing has changed in the intervening years.

Nevertheless, hope springs eternal. I keep wishing something or someone would prod the FAA to improve the way NOTAMs are disseminated. Not only would flying be safer, but if time really is money, we’d be a whole lot richer, too.

Those Lousy Checklists

Friday, May 1st, 2015

Ah, the checklist. If Shakespeare was a pilot, he’d have written an ode to it.

Once confined to the world of aviation, formal checklist discipline is now common in hospitals, assembly lines, product design, maintenance, and just about any other instance where loss of essential time, money, or bodily function can result from improper procedures or forgotten items.

Some pilots can’t imagine flying without one. Like a child wandering the yard without their favorite blanket, they’d quite literally be lost without that laminated piece of paper guiding them through each phase of flight. I’ve seen pilots who seemed to enjoy using the checklist more than the actual flying.

Others have a difficult time understanding why a written list is needed at all, especially in simple or familiar aircraft. “Use a flow or mnemonic and let’s get going!”, they’d say. While I disagree with that attitude, I understand where it comes from: too many badly-designed checklists.

As anyone who’s operated a wide variety of aircraft types (I’ve flown over 60) can tell you, poor checklists are more often the rule than the exception, and the worst of them will leave a long-lasting bad taste in your mouth. They disrupt the flow of a flight much the way an actor with poor timing can disrupt a scene.

One of the great aviation mysteries is why so many lousy checklists continue to exist. They’re not limited to small aircraft, either. The manufacturer-provided checklist for the Gulfstream IV, for example, is comically long. I don’t know who designs these things, but I highly doubt it’s the line pilot who’s going to be using it day in and day out.

The answer to such cosmic riddles is far above my pay grade. What I can say for sure is that it’s vital for aviators to understand both the purpose for a checklist and the proper way to use one.

The purpose should be self-evident: to ensure that nothing important gets missed. Lowering the landing gear, setting the pressurization controller, those sorts of items. The key word is important, and I think that’s where many checklists fall apart because once the document gets too long, human nature dictates that pilots will either skip items inadvertently or leave the entire thing stowed.

Proper checklist usage? Now that’s something a bit more complex. When an aviator is new to an aircraft, the checklist serves as a “do” list. In other words, each item is read and then the action is performed. Even if a cockpit flow exists and is being taught, the list will have to be read and performed one step at a time because the pilot is simply unfamiliar with the location of switches and controls.

As time goes by, the flow and/or checklist is slowly memorized. Eventually the pilot reaches the point where they’re actually faster and more comfortable performing the items from memory. There’s absolutely nothing wrong with that. In fact, it’s a good thing, because it allows the checklist to serve as a CHECK list. Once everything is done, you quickly read through the items on the page to ensure you haven’t forgotten anything.

In my experience, it’s not the neophyte who is at greatest risk for missing something, it’s the grizzled veteran who whips through the flows at lightning speed and then neglects to use the checklist at all. It’s overconfidence. They’re so sure they haven’t forgotten anything of life-altering consequence. And to be honest, they’re usually right — but that’s not the point.

I see this kind of failure quite frequently when flying glass panel aircraft with pilots who are computer-centric Type-A personalities. They’re literally too fast with the flows and need to slow down a bit.

Caution is also warranted when circumstances force a pilot to perform tasks out of their normal order. Often this happens due to interruption from ATC, line personnel, passengers, weather, or even another pilot.

Speaking of weather, here’s a case in point: I was in New Jersey getting a jet ready for departure during a strong rainstorm. We had started up the airplane to taxi to a place on the ramp where it was somewhat protected from the weather so our passengers wouldn’t get quite as soaked when they arrived. That simple action broke up the usual preflight exterior flow and as a result I neglected to remove the three landing gear pins. Thankfully the other pilot caught it during his walk-around, but it shows how easily that sort of thing can happen.

The best checklists, the ones that are truly effective, share some common traits. For one thing, they’re short and sweet. They hit the critical items in a logical order and leave the rest out.

In an aerobatic aircraft, a pre-takeoff check would cover the fuel selector, canopy, fuel mixture, flight controls, etc. In a swept-wing business jet, on the other hand, the critical items are different. Flaps become a vital item, because unlike other aircraft, if those aren’t set right the airplane can use far more runway than you’ve got available. It may not even fly at all.

Checklist design and usage is an under-appreciated skill. As with many things in aviation, when it’s done right it’s a thing of elegance. Art, almost. So next time you’re flying, take a critical look at your checklist and the way you use it. How do you — and it — measure up?

The Weakest Link

Thursday, April 16th, 2015

If one particular component of an aircraft was determined to be the root cause of 90% of all accidents, wouldn’t we have an Airworthiness Directive out on it? Wouldn’t it be replaced completely? Well we do have such a component: the pilot.

We’re at the point where this isn’t just an academic exercise. A pilot-free airliner or business aircraft is well within the realm of today’s technology. NASA has been researching single-pilot airline cockpits; that gets us halfway there. Corporate aircraft ranging from King Airs to Citations have been certified and operated by a single pilot for decades.

On the other hand, after the Germanwings disaster virtually every airline now has a policy ensuring there are never less than two people on the flight deck — the exact opposite. So which way should we be heading?

Your average pilot probably doesn’t think of him or herself as the weakest link. I certainly don’t. But those pesky statistics…

It brings to mind the illusory superiority bias, that statistically improbably belief of being above average. The most famous example concerns drivers:

According to a study published in a Swedish Psychology journal (Acta Psychologica) a whopping 93% of Americans consider themselves above average drivers. The sample consisted of students, and while the study was conducted in multiple countries, it because obvious that Americans saw themselves as even better drivers than their Swedish counterparts. The Swedish came in at a much lower 69%.

In another similar study by McCormick, Walkey and Green (1986) drivers rated them 80% above average.

Despite extensive training on hazardous attitudes and ADM, pilots aren’t immune to this phenomenon. We’re still human. In fact, the successful, driven type of personality our avocation attracts probably make it more common than in the automotive world. If 93% of drivers feel they’re above average, one wonders how high the needle swings on the pilot population. Who among us wants to admit that despite the massive investment of time, effort, and money we are still subpar?

Are we the weakest link?

Are we the weakest link?

That sort of acknowledgement can be pretty hard on a person’s self-image, but aviators should care about this phenomenon because nine out of 10 accidents are attributed to pilot error. In other words, we literally are the weakest link.

I certainly include myself in that statement. If I had a dime for every mistake I’ve made over the years! Sometimes I think I’ve made them all. In fact a friend of mine — a professional pilot who is known as an excellent aviator — once said that in reviewing the NASA-style safety reports made by line pilots at his company, “I find I’ve made every one of those mistakes myself. Every single one.”

To err may be human, but it’s grating to find myself making the same mistake multiple times; doing so runs a little too close to Einstein’s definition of insanity. For example, I’ve flown while suffering from active food poisoning on two occasions. The circumstances were not identical, but you’d think I’d have learned enough from one episode to have avoided the other.

The first case hit me during a picnic at the Santa Ynez Airport. I had two choices: stay in town or fly home. I chose the latter, and while I made it back without incident, it was a lousy decision to takeoff when feeling so bad.

The second incident occurred at an aerobatic contest in Delano, California. These contests take place in areas where it’s hot and windy. Pilots assist with contest operation when they’re not flying, meaning we’re busy and spend most of the day out in the sun. It’s common to end up dehydrated even while drinking plenty of water. I ate something which didn’t agree with me, and by the time I realized how bad the poisoning was, I’d already flown a hard aerobatic sequence.

This is why I’ve come to be a big believer in the IMSAFE checklist. Amy Laboda just wrote about the importance of this checklist a few days ago. If we can ensure the biological component of our flying is in airworthy shape, the odds of a safe flight rise considerably. IMSAFE isn’t even a complete checklist. It doesn’t mention nutrituion, for example — something my wife will tell you I sometimes ignore.

Pilots may be the cause of most accidents, but in my experience they’re also the cause of many “saves”. Quantas 32, Apollo 13, United 232, Air Canada 143, and USAir 1549 are just a few famous examples of human ingenuity keeping what should have been an unrecoverable mechanical failure at bay. I know of several general aviation incidents which turned out well due to the creative efforts of the pilots. These typically don’t make the evening news, and I imagine there are countless more we’ll never hear about, because when a flight lands without incident it doesn’t generate much attention or publicity. Accident statistics do us a disservice in that regard.

This is why I feel removing humans from the cockpit is not the answer. Commercial flying already holds claim as the safest form of transportation. Light general aviation is a different story, but that’s the price we pay for the incredible freedom and diversity offered by Part 91. No, we would be better served by focusing on improved aeronautical decision making, self-assessment, and training. As I’ve found through bitter experience, it’s a constant battle. Just because you’ve made a thousand flights without incident doesn’t mean your next one will be safe. It’s up to each of us to maintain vigilance throughout every single one of our airborne days.

Statistically speaking, we are the weakest link. But we don’t have to be.

When to get some Dual on the couch: mental and emotional health needs of pilots

Monday, April 6th, 2015
Take a breath, take an honest look

Take a breath, take an honest look

Recently I suffered three unexpected losses. I use the word suffered on purpose here. In December I needed to get a flight review. I had scheduled this with three instructors, but due to the holidays, I was unable to get it done. In early January I contacted a local CFI that I know only socially. He knew about the losses in my life. After talking with me a few moments, he gently suggested that I was not well enough emotionally to fly that day. Of course, I burst into tears because he was number four on my list of instructors.

After I got done crying about it, I got to thinking about how, as a professional psychotherapist, I was seemingly unable to see the state of my own mental health. Below is an excerpt of an article I wrote for AOPA Pilot as well as a link for online screening tools for depression, anxiety, bi-polar and PTSD.

Here are some simple ways to put you and your emotional health on the pre-flight checklist as well as some ideas on when to get support if needed.

Mood: Think back over the past week. Rate your mood on a 1 to 5 scale with 1 being the lowest, and 5 being a happy mood. What is your average? Has anyone told you that you look tired, depressed, or nervous? Sometimes our spouse or families are the greatest mirrors for us. We might not see our mood, but to them it is written all over our faces.

Sleep: Have you been sleeping well? The average person in a lab setting will sleep a 6-7 hour stretch and take a 1-2 hour nap in the afternoon. Think back and check whether you have had any difficulties falling or staying asleep. Our deep restorative delta sleep typically happens well into an uninterrupted sleep cycle. Think about performing a go-round on every approach, with sleep we simply cannot get down to delta if the cycle is continually disrupted.

Energy: Has your get up and go, got up and went? Do you find yourself drinking coffee or energy drinks just to get through the day? Some pilots find they have too much energy and are unable to relax into a healthy focus. Between the tortoise and the hare, somewhere in the middle of the two is the most efficient.

Anxiety and Worry: Someone once told me that worry is interest on a debt we don’t yet owe. An interesting study on worry shows that it can be healthy in small doses. Worry is a high brain function, one that can help us sort through possibilities and strategies. Too much worry shuts down the function and we can find ourselves in a lower brain: fight, flight, or freeze. 30 minutes of worry once per week is effective. How many minutes this week have you racked up?

Concentration/Focus: Particularly important in being pilot-in command [PIC] is the ability to concentrate and stay focused. If you are noticing that your mind is wandering or you are distracted by worry, it might be best to keep yourself and the aircraft on the ground.

Sex Drive: This might seem a strange item to have on your personal checklist, but the fact is a person’s sex drive can be indicative of emotional health. A lack of desire can be suggestive of a mood problem.

Appetite: Does your favorite food taste good to you? Are you eating for comfort or to excess? Healthy food is fuel for the brain and the body. Make sure that you do not fly without fuel on board.

Bumper Sticker: Ask yourself this question and pay attention to the answer: If you had to summarize your attitude about life to fit on a bumper sticker, what would yours say? Is your bumper sticker upbeat and optimistic, or doubtful and negative?

Below is a link for the Mental Health America online screening tools. These screening tools are for use with adults only. If your screening indicates a problem, it is best to contact a licensed mental health counselor in your community for follow-up.

A few days after my crying spell, I completed my flight review and had a great time doing it. My instructor had not flown in a Mooney for some time, and after the necessary maneuvers, I was able to show him a lot about my airplane.

Me and Dad, Christmas Eve

James and Jolie Lucas

One of my losses was the death of my father who was a primary flight instructor in the Army Air Corp and a Mooney pilot for 30 plus years. The day I was to leave for his memorial I was checking and double-checking the weather. I thought to myself, “I wonder if I am okay to fly?” That was the only question I needed to ask. If you wonder if you are okay, you are not okay. I packed up the car and made the five-hour drive with my son. While an hour and a half in the air is quicker, for me, that day, the drive was safer.

Our mental health is equally important as our physical health. We are all subject to the same rules of stress and loss. I am happy that CFI #3 told me he didn’t think I should be flying. His insight could have saved us from a bad outcome. I believe we all do need to have eyes and ears on our fellow pilots. We are a small community and we all get to do something that we love to do. Let’s all make sure we are up to the task emotionally too. Thanks for listening.


Flying Backward

Wednesday, February 11th, 2015

“Aviation in itself is not inherently dangerous. But to an even greater degree than the sea, it is terribly unforgiving of any carelessness, incapacity or neglect.”

Aviation insurance pioneer A. G. Lamplugh uttered that oft-quoted phrase more than eighty years ago, and it’s as valid today as it was back then. Like Newton’s Laws of Physics, it’s one of the basic, unchanging truths about flying: certain things simply must be done properly if we’re to avoid disaster in the air. One of the best examples would be dealing with a low-altitude engine failure.

Last week’s TransAsia ATR-72 accident is a potent reminder of this aphorism. While we don’t know the cause yet and probably won’t know the whole story for a year or more, it got me thinking about how oddly things are done in aviation sometimes. For example, airline pilots move “up” the food chain from turboprops to jets. If safety is the paramount concern, that’s backwards. Shouldn’t the most experienced pilots should be exercising their skills on the most challenging aircraft rather than the least?

While jets certainly have their pitfalls and perils, a low-altitude engine failure is generally more challenging in a turboprop. The dead engine’s propeller creates tremendous drag until it’s properly secured. Many multi-engine turboprops are equipped with mechanisms to automatically feather the offending prop, but if that system doesn’t function properly, has been deferred, or simply doesn’t exist, the pilot is faced with six levers in close proximity, only one of which will do the trick. It’s easy to pull the wrong one.

Worse yet, if the craft has an autofeather system, the pilot would logically expect it to function as advertised. He or she would have to first detect the lack of feathering, then run the identify-verify-feather drill. Unlike training scenarios, there’s a major surprise factor at play as well. In a simulator, is anyone really surprised when the engine quits? Of course not. In the real world, pilots make thousands of flights where a powerplant doesn’t fail. As much as you tell yourself with each takeoff that “this could be the one”, empirical evidence in the form of a pilot’s own experience suggests against it. That makes preparation for a low-altitude emergency a constant battle with oneself. Are we always honest about how we’re doing in that fight? Probably not.

When I flew ex-military U-21A turboprops for a government contractor, we did all our training in the actual aircraft. I’ll never forget how marginal the aircraft’s performance was, even when engine failures were handled properly and expediently. We would fly a single-engine approach into Catalina Airport, where the missed approach procedure takes you toward the center of the island and some fairly high terrain. On one training flight the autofeather system initially worked as advertised, but then started to slowly unfeather.

Turboprop flying also comes with increased risk exposure due to the flight profile. A jet pilot might fly one or two legs a day versus five, six, or seven flown by the guy in the turboprop. With more legs comes an increased statistical opportunity for that engine to quit on takeoff. Turboprops also fly at lower altitudes where they tend to be in weather rather than above it.

The reciprocating twin pilot has it even worse when it comes to performance. Most of them have no guarantee of any climb performance at all on one engine, especially with the gear down, and few are equipped with automatic feathering systems. Yet that’s where we all start out.

Contrast this with engine failure in the modern jet, where the pilot need do nothing but raise the landing gear and keep the nose straight. In my aircraft, at least, we don’t even add power on the remaining engine. Unless the plane is literally on fire, we just climb straight out for a minute or two, gaining altitude and doing… nothing. No checklist to run, and only two levers in the throttle quadrant rather than six.

John Deakin described the contrast between prop and jet quite colorfully when he transitioned into the G-IV:

“If you hear a Gulfstream pilot whine about poor performance when high, hot, and heavy, please understand, he’s whining about less than 1,000 feet per minute on one engine. I sometimes feel like slapping a chokehold on, and dragging one of these guys out to the old C-46, loaded, on a hot day, and make him do an engine failure on takeoff, where he’d be lucky to get 50 feet per minute.”

There are other places where you can see this same phenomenon at work in aviation. Consider the world of flight instruction. The least experienced CFIs typically start off by teaching primary students. Again, that’s backwards. It would seem more logical to start instructors off with checkouts and endorsements for experienced pilots or commercial certificate training. Putting the best, most experienced CFIs with the neophytes might help accelerate their progress and alleviate the high student pilot drop-out rate.

The Law of Primacy — something every CFI candidate learns about — tells us that “the state of being first, often creates a strong, almost unshakable, impression. Things learned first create a strong impression in the mind that is difficult to erase. For the instructor, this means that what is taught must be right the first time.” Primary flight training literally sets the foundation of an aviator’s flying life, to say nothing of the fact that teaching primary students is one of the most difficult jobs a CFI can undertake. So why is this critical task mainly entrusted to the newest, least experienced instructors?

The answer to these questions usually comes down to money. The almighty dollar frequently plays a powerful role in explaining the unexplainable in aviation. While it would be unrealistic to deny the importance of financial concerns in defying gravity, whole sections of the aviation ecosystem run backwards and one can’t help but wonder if perhaps safety suffers because of it.

Who’s the Best Pilot?

Monday, December 22nd, 2014

One of the many iconic scenes (so much so that it recurs several times in the film) from The Right Stuff has astronaut Gordon Cooper asking his wife, “Who’s the best pilot you ever saw?” before answering his own question: “You’re lookin’ at him!” Gordo was telling a joke, of course, but it got me thinking about what constitutes a great pilot in the real world.

Accident statistics show that when light GA pilots try to operate on a firmly fixed schedule — for example, around the holidays — the risk level increases. AOPA recently published an Air Safety Alert to that effect, noting “a cluster of GA accidents occurring in close succession.”

Some of this probably has to do with the fact that the holiday season occurs in the winter for those of us living in the northern hemisphere. While the hot months have their own set of challenges, they tend to consist of things which present equal hazard to all aircraft: thunderstorms, high density altitude, etc. But whereas large multi-engine turbojets are well-equipped for cold weather flying, single-engine recips typically operate with minimal anti- and de-icing equipment, if any.

Anyway, it occurs to me that this kind of flying is exactly what we do in the Part 135 world. We operate on someone else’s timetable, and rarely is that schedule created with weather, circadian rhythm, airport staffing hours, or other such operational concerns in mind. As you might expect, the 135 safety record — while far better than Part 91 — does not reach the rarefied heights of the scheduled airlines. Some people feel it should. There are plenty of folks who feel Part 91 should reach that strata as well.

I tend to disagree.

Part 135 has the flexibility to operate at random times and into a far wider variety of places than scheduled airlines. While we do everything possible to make the flights as safe as humanly possible, flexibility cannot help but exact a price. Flying worldwide charter, I don’t know if my next trip will take me to Liberia or Las Vegas. I have to be prepared to go anywhere.

If that sounds incredible, then light general aviation flying should really blow your mind! The non-commercial Part 91 aviating so many of us do for personal reasons takes that freedom and ramps it up a hundred fold. Not only can you go anywhere you want at any time it suits you, you can do it at night, in IMC, in formation, and fly some aerobatics or sight-see along the way. You can fly a weird experimental airplane that you built in your garage. You can tow banners. Drop things from your airplane, then cut them up as they fall to earth? Yes, that’s fine. Fly high… or low. You can change your destination in mid-flight without asking anyone’s permission.

Heck, you can even take off with no destination whatsoever; those are some of my most cherished flights. When I call the VFR clearance delivery frequency at John Wayne Airport and they ask where I’m headed, nothing says freedom quite like using William Shatner’s response from the first Star Trek film: “Out there. That-a-way!”

Wrapping your mind around having the liberty to do those things while not being able to install a radio in your panel without approval from a certification office somewhere in Oklahoma City could cause a migraine… but let’s leave that for another day.

The point is, with added freedom comes added risk. And responsibility. It’s ironic that we think of airline pilots as having the greatest weight on their shoulders when rules, procedures, and operational specifications dictate almost everything they do. I’m not saying their job is easy. It ain’t. But if you’re not in awe of the authority and self-determination placed on your own shoulders every time you launch, think about this: we could have the safety record of the major airlines. All we’d need are the same rules and requirements for flight that they use. Seems to me that would be an awful lot like asking Santa for a big, dirty lump of coal in your stocking.

If there’s a way to have the freedom to land on five hundred foot long strips on the side of a mountain, tackle water runways, engage in flight training, and — most of all — fly to that family Christmas in an airplane with just one reciprocating engine without significantly higher risk than you’ll find on a typical airliner, I’d be quite surprised. But one thing every pilot has in common is that risk management is a major part of the job.

So as you contemplate that cross-country flight to celebrate the holidays with your loved ones, remember that the best pilot isn’t the one who finds the cheapest fuel, stuffs the most presents into the baggage compartment, or makes the softest landing. It’s the one who best manages the risk inherent in that flight.

Right, Gordo?

Upset Recovery Training vs. Aerobatics

Tuesday, October 28th, 2014

Upset recovery training has been all the rage over the past couple of years. A Google search of that exact phrase returns more than 24,000 results. There’s a professional association dedicated to such training. ICAO even declared aircraft upsets to be the cause of “more fatalities in scheduled commercial operations than any other category of accidents over the last ten years.”

Nevertheless, I get the impression that some folks wonder if it isn’t more of a safety fad than an intrinsic imperative. It’s hard to blame them. You can hardly open a magazine or aviation newsletter these days without seeing slick advertisements for this stuff. When I was at recurrent training a couple of months ago, CAE was offering upset recovery training to corporate jet pilots there in Dallas. “If I wanted to fly aerobatics, I’d fly aerobatics!” one aviator groused.

He didn’t ask my opinion, but if he had, I’d remind him that 99% of pilots spend 99% of their time in straight and level flight — especially when the aircraft in question is a business jet. I’m not exaggerating much when I say that even your typical Skyhawk pilot is a virtual aerobat compared to the kind of flying we do on charter and corporate trips. For one thing, passengers pay the bills and they want the smoothest, most uneventful flight possible.

In addition, these jets fly at very high altitudes – typically in the mid-40s and even as high as 51,000 feet. Bank and pitch attitudes tend to stay within a narrow band. Yaw? There shouldn’t be any. The ball stays centered, period. We aim for a level of smoothness that exceeds even that of the airlines. Passengers and catering may move about the cabin frequently during a flight, but it shouldn’t be because of anything we’re doing up front.

Fly like that for a decade or two, logging thousands and thousands of uneventful, straight-and-level hours and the thought of all-attitude flying can become – to put it mildly – uncomfortable. I’ve even seen former fighter pilots become squeamish at the thought of high bank or pitch angles after twenty years of bizjet flying.

Unfortunately, there are a wide variety of things that can land a pilot in a thoroughly dangerous attitude: wind shear, wake turbulence, autopilot failure, mechanical malfunction (hydraulic hard-overs, asymmetric spoiler or flap deployment, etc.), inattention, and last but not least, plain old pilot error. Look at recent high-profile accidents and you’ll see some surprisingly basic flying blunders from the crew. Air France 447, Colgan 3407, and Asiana 214 are just three such examples. It may not happen often, but when it does it can bite hard.

So yes, I think there is a strong need for more manual flying exposure in general, and upset recovery training in particular. This isn’t specific to jet aircraft, because some light aircraft have surpassed their turbine-powered cousins in the avionics department. I only wish the 1980’s era FMS computer in my Gulfstream was as speedy as a modern G1000 installation.

Defining the Problem

To the best of my knowledge, neither the NTSB or FAA provide a standard definition for “upset”, but much like Supreme Court Justice Potter Stewart, we pretty much know it when we see it. The term has generally come to be defined as a flight path or aircraft attitude deviating significantly from that which was intended by the pilot. Upsets have led to loss of control, aircraft damage or destruction, and more than a few fatalities.

As automation proliferates, pilots receive less hands-on experience and a gradual but significant reduction in stick-and-rudder skill begins to occur. The change is a subtle one, and that’s part of what makes it so hazardous. A recent report by the FAA PARC rulemaking workgroup cites poor stick and rudder skills as the number two risk factor facing pilots today. The simple fact is that windshear, wake turbulence, and automation failures happen.

The purpose of upset recovery training is to give pilots the tools and experience necessary to recognize and prevent impending loss of control situations. As the saying goes, an ounce of prevention is worth a pound of cure, and that’s why teaching recovery strategies from the most common upset scenarios is actually a secondary (though important) goal.

What about simulators? They’ve proven to be an excellent tool in pilot training, but even the most high fidelity Level D sims fall short when it comes to deep stalls and loss of control scenarios. For one thing, stall recovery is typically initiated at the first indication of stall, so the techniques taught in the simulator may not apply to a full aerodynamic stall. Due to the incredibly complex and unpredictable nature of post-stall aerodynamics, simulators aren’t usually programmed to accurately emulate an aircraft in a deeply stalled condition. Thus the need for in-aircraft experience to supplement simulator training.

Upset Recovery vs. Aerobatics

It’s important to note that upset recovery training may involve aerobatic maneuvering, but it does not exist to teach aerobatics. Periodically over the years, discussions on the merits of this training will cause a co-worker to broach the subject of flying an aerobatic maneuver in an airplane which is not designed and built for that purpose. This happened just the other day. Typically they’ll ask me if, as an aerobatic pilot, I would ever consider performing a barrel or aileron roll in the aircraft.

I used to just give them the short answer: “no”. But over time I’ve started explaining why I think it’s such a bad idea, even for those of us who are trained to fly such maneuvers. I won’t touch on the regulations, because I think we are all familiar with those. I’m just talking about practical considerations.

Normal planes tend to have non-symmetrical airfoils which were not designed to fly aerobatics. They feature slower roll rates, lower structural integrity under high G loads, and considerably less control authority. You might have noticed that the control surfaces on aerobatic airplanes are pretty large — they are designed that way because they’re needed to get safely into and out of aerobatic maneuvers.

That’s not to say an airplane with small control surfaces like a business jet or light GA single cannot perform aerobatics without disaster striking. Clay Lacy flies an airshow sequence in his Learjet. Duane Cole flew a Bonanza. Bob Hoover used a Shrike Commander. Sean Tucker flew an acro sequence in a Columbia (now known as the Cessna TTx). However, the margins are lower, the aerobatics are far more difficult, and pilots not experienced and prepared enough for those things are much more likely to end up hurt or dead.

Sean Tucker will tell you that the Columbia may not recover from spins of more than one or two turns. Duane Cole said the Bonanza (in which he did inverted ribbon cuts) had barely enough elevator authority for the maneuver, and it required incredible strength to hold the nose up far enough for inverted level flight. Bob Hoover tailored his performance to maneuvers the Shrike could do — he’ll tell you he avoided some aerobatic maneuvers because of the airplane’s limitations.

Knowing those limitations and how to deal with them — that’s where being an experienced professional aerobatic pilot makes the difference. And I’m sure none of those guys took flying those GA airplanes upside down lightly. A lot of planning, consideration, training and practice went into their performances.

Now, consider the aircraft condition. Any negative Gs and stuff will be flying around the cabin. Dirt from the carpet. Manuals. Items from the cargo area. Floor mats. Passengers. EFBs. Drinks. Anything in the armrest or sidewall pockets. That could be a little distracting. Items could get lodged behind the rudder pedals, hit you in the head, or worse.

If the belts aren’t tight enough, your posterior will quickly separate from the seat it’s normally attached to. And I assure you, your belts are not tight enough. Getting them that way involves cinching the lap belt down until it literally hurts. How many people fly a standard or transport category aircraft that way?

Now consider that the engine is not set up for fuel and oil flow under negative Gs. Even in airplanes specifically designed for acro, the G loads move the entire engine on the engine mount. In the Decathlon you can always see the spinner move up an inch or two when pushing a few negative Gs. Who knows what that would do with the tighter clearances between the fan and engine cowl on an airplane like the Gulfstream?

Next, let’s consider trim. The jet flies around with an electric trim system which doesn’t move all that quickly. The aircraft are typically trimmed for upright flight. That trim setting works heavily against you when inverted, and might easily reach the point where even full control deflection wouldn’t be sufficient.

I could go on, but suffice it to say that the more I learn about aerobatics, the less I would want to do them in a non-aerobatic aircraft – and certainly not a swept wing jet! Sure, if performed perfectly, you might be just fine. But any unusual attitude is going to be far more difficult — if not outright impossible — to recover from.

Dang it, Tex!

Every time someone references Tex Johnson’s famous barrel roll in the Boeing 707 prototype, I can’t help but wish he hadn’t done that. Yes, it helped sell an airplane the company had staked it’s entire future on, but aerobatic instructors have been paying the price ever since.

Aerobatic and upset recovery training: good. Experimenting with normal category airplanes: bad. Very bad.

Carbon Monoxide, Silent Killer

Monday, October 20th, 2014

Danger, Carbon Monoxide
On January 17, 1997, a Piper Dakota departed Farmingdale, New York, on a planned two-hour VFR flight to Saranac Lake, New York. The pilot was experienced and instrument-rated; his 71-year-old mother, a low-time private pilot, occupied the right seat. Just over a half-hour into the flight, Boston Center got an emergency radio call from the mother, saying that the pilot (her son) had passed out.

The controller attempted a flight assist, and an Air National Guard helicopter joined up with the aircraft and participated in the talk-down attempt. Ultimately, however, the pilot’s mother also passed out.

The aircraft climbed into the clouds, apparently on autopilot, and continued to be tracked by ATC. About two hours into the flight, the airplane descended rapidly out of the clouds and crashed into the woods near Lake Winnipesaukee, New Hampshire. Both occupants died.

Toxicological tests revealed that the pilot’s blood had a CO saturation of 43% — sufficient to produce convulsions and coma—and his mother’s was 69%.

On December 6 that same year, a physician was piloting his Piper Comanche 400 from his hometown of Hoisington, Kansas, to Topeka when he fell asleep at the controls. The airplane continued on course under autopilot control for 250 miles until it ran a tank dry and (still on autopilot) glided miraculously to a soft wings-level crash-landingin a hay field near Cairo, Missouri.

The pilot was only slightly injured, and walked to a nearby farmhouse for help. Toxicology tests on a blood sample taken from the lucky doc hours later revealed CO saturation of 27%. It was almost certainly higher at the time of the crash.

Just a few days later, a new 1997 Cessna 182S was being ferried from the Cessna factory in Independence, Kansas, to a buyer in Germany when the ferry pilot felt ill and suspected carbon monoxide poisoning. She landed successfully and examination of the muffler revealed that it had been manufactured with defective welds. Subsequent pressure tests by Cessna of new Cessna 172 and 182 mufflers in inventory revealed that 20% of them had leaky welds. The FAA issued an emergency Airworthiness Directive (AD 98-02-05) requiring muffler replacement on some 300 new Cessna 172s and182s.

About 18 months later, the FAA issued AD 99-11-07 against brand new air-conditioned Mooney M20R Ovations when dangerous levels of CO were found in their cabins.

Sidebar: CO Primer

Click on image above for high-resolution printable version.

Not just in winter

A search of the NTSB accident database suggests that CO-related accidents and incidents occur far more frequently than most pilots believe. Counterintuitively, these aren’t confined to winter-time flying with the cabin heat on. Look at the months during which the following accidents and incidents occurred during the 15-year period from 1983 to 1997:

March 1983. The Piper PA-22-150 N1841P departed Tucumcari, N.M. After leveling at 9,600, the right front seat passenger became nauseous, vomited, and fell asleep. The pilot began feeling sleepy and passed out. A 15-year-old passenger in the back seat took control of the aircraft by reaching between the seats, but the aircraft hit a fence during the emergency landing. None of the four occupants were injured. Multiple exhaust cracks and leaks were found in the muffler. The NTSB determined the probable cause of the accident to be incapacitation of the PIC from carbon monoxide poisoning. [FTW83LA156]

February 1984. The pilot of Beech Musketeer N6141N with four aboard reported that he was unsure of his position. ATC identified the aircraft and issued radar vectors toward Ocean Isle, N.C. Subsequently, a female passenger radioed that the pilot was unconscious. The aircraft crashed in a steep nose-down attitude, killing all occupants. Toxicological tests of the four victims revealed caboxyhemoglobin levels of 24%, 22%, 35% and 44%. [ATL84FA090]

November 1988. The Cessna 185 N20752 bounced several times while landing at Deadhorse, Alaska. The pilot collapsed shortly after getting out of the airplane. Blood samples taken from the pilot three hours after landing contained 22.1% carboxyhemoglobin. The left engine muffler overboard tube was broken loose from the muffler where the two are welded. The NTSB determined probable cause to be physical impairment of the pilot-in-command due to carbon monoxide poisoning. [ANC89IA019]

July 1990. While on a local flight, the homebuilt Olsen Pursuit N23GG crashed about three-tenths of a mile short of Runway 4 at Fowler, Colo. No one witnessed the crash, but post-crash investigation indicated that there was no apparent forward movement of the aircraft after its initial impact. The aircraft burned, and both occupants died. Toxicology tests of the pilot and passenger were positive for carboxyhemoglobin. [DEN90DTE04]

August 1990. About fifteen minutes into the local night flight in Cessna 150 N741MF, the aircraft crashed into Lake Michigan about one mile from the shoreline near Holland, Mich. Autopsies were negative for drowning, but toxicological tests were positive for carboxyhemoglobin, with the pilot’s blood testing at 21%. [CHI90DEM08]

July 1991. The student pilot and a passenger (!) were on a pleasure flight in Champion 7AC N3006E owned by the pilot. The aircraft was seen to turn into a valley in an area of mountainous terrain, where it subsequently collided with the ground near Burns, Ore., killing both occupants. A toxicology exam of the pilot’s blood showed a saturation of 20% carboxyhemoglobin, sufficient to cause headache, confusion, dizziness and visual disturbance. [SEA91FA156]

October 1992. The pilot of Cessna 150 N6402S was in radio contact with the control tower at Mt. Gilead, Ohio, and in a descent from 5,000 feet to 2,000 feet in preparation for landing. Radar contact was lost, and the aircraft crashed into a wooded area, seriously injuring the pilot. Toxicological tests on the pilot’s blood were positive for carbon monoxide. Examination of the left muffler revealed three cracks and progressive deterioration. The NTSB found probable cause of the accident to be pilot incapacitation due to carbon monoxide poisoning. [NYC93LA031]

April 1994. Fifteen minutes after takeoff from Long Beach, Calif., the Cessna 182 N9124G began deviating from headings, altitudes and ATC instructions. The aircraft did several 360- and 180-degree turns. The pilot reported blurred vision, headaches, nausea, labored breathing, and difficulty staying awake. The aircraft ultimately crashed in a vineyard near Kerman, Calif., and the owner/pilot was seriously injured. Post-crash inspection revealed numerous small leaks in the exhaust system. The pilot tested positive for carbon monoxide even after 11 hours of oxygen therapy. [LAX94LA184]

October 1994. A student pilot returned to Chesterfield, Mo., from a solo cross-country flight in Cessna 150 N7XC, complaining of headache, nausea, and difficulty walking. The pilot was hospitalized, and medical tests revealed elevated CO which required five and a half hours breathing 100% oxygen to reduce to normal levels. Post-flight inspection revealed a crack in an improperly repaired muffler that had been installed 18 hours earlier. [CHI95IA030]

March 1996. The pilot of Piper Cherokee 140 N95394 stated that she and her passenger became incapacitated after takeoff from Pittsburg, Kan. The airplane impacted the terrain, but the occupants were uninjured. Both were hospitalized, and toxicological tests for carbon monoxide were positive. A subsequent examination found holes in the muffler. [CHI96LA101]

August 1996. A Mankovich Revenge racer N7037J was #2 in a four-airplane ferry formation of Formula V Class racing airplanes. The #3 pilot said that the #2 pilot’s flying was erratic during the flight. The airplane crashed near Jeffersonville, Ind., killing the pilot. The results of FAA toxicology tests of the pilot’s blood revealed a 41% saturation of carboxyhemoglobin; loss of consciousness is attained at approximately 30%. Examination of the wreckage revealed that the adhesive resin that bound the rubber stripping forming the firewall lower seal was missing. The NTSB determined probable cause of the accident to be pilot incapacitation due to carbon monoxide poisoning. [CHI96FA322]

January 1997. The fatal crash of Piper Dakota N8263Y near Lake Winnipesaukee, N.H. (described previously). [IAD97FA043]

December 1997. Non-fatal crash of Piper Comanche 400 N8452P flying from Hoisington to Topeka, Kansas (described previously). [CHI98LA055]

December 1997. A new Cessna 182S was being ferried from the factory in Independence, Kan., to a buyer in Germany when the ferry pilot felt ill and suspected carbon monoxide poisoning (described previously). [Priority Letter AD 98-02-05]

Overall, deaths from unintentional carbon monoxide poisoning have dropped sharply since the mid-1970s thanks mainly to lower CO emissions from automobiles with catalytic converters (most CO deaths are motor vehicle-related) and safer heating and cooking appliances. But CO-related airplane accidents and incidents haven’t followed this trend. The ADs issued against Independence-built Cessna 172s and 182s and Mooney Ovations demonstrates that even brand new airplanes aren’t immune.

CO Checklist

Click on image above for high-resolution printable version.

Close calls

In addition to these events in the NTSB accident database where CO poisoning was clearly implicated, there were almost certainly scores of accidents, incidents, and close calls where CO was probably a factor.

In January 1999, for example, a Cessna 206 operated by the U.S. Customs Service was on a night training mission when it inexplicably crashed into Biscayne Bay a few miles off the south Florida coast. The experienced pilot survived the crash, but had no recollection of what happened. The NTSB called it simple pilot error and never mentioned CO as a possible contributing factor. However, enough carboxyhemoglobin was found in the pilot’s blood that the Customs Service suspected that CO poisoning might have been involved.

The agency purchased sensitive industrial electronic CO detectors for every single-engine Cessna in its fleet, and discovered that many of the planes had CO-in-the-cockpit problems. On-board CO detectors and CO checks during maintenance inspections have been standard operating procedure for the Customs Service ever since.

How much CO is too much?

It depends on whom you ask.

EPA calls for a health hazard alert when the outdoor concentration of CO rises above 9 parts per million (ppm) for eight hours, or above 35ppm for one hour. OSHA originally established a maximum safe limit for exposure to CO in the workplace of 35 ppm, but later raised it to 50 ppm under pressure from industry.

The FAA requires that CO in the cabin not exceed 50 ppm during certification testing of new GA airplanes certified under FAR Part 23 (e.g. Cessna Corvallis, Cirrus SR22, Diamond DA-40). Legacy aircraft certified under older CAR 3 regs required no CO testing at all during certification.

Once certified, FAA requires no CO testing of individual aircraft by the factory, and no follow-up retesting during annual inspections. A March 2010 FAA SAIB (CE-10-19 R1) recommends checking CO levels with a hand-held electronic CO detector during ground runups at each annual and 100-hour inspection, but in my experience very few shops and mechanics do this.

UL-approved residential CO detectors are not permitted to alarm until the concentration rises to 70 ppm and stays there for four hours. (This was demanded by firefighters and utility companies to reduce the incidence of nuisance calls from homeowners.) Yet most fire departments require that firefighters put on their oxygen masks immediately when CO levels reach 25 ppm or higher.

It’s important to understand that low concentrations of CO are far more hazardous to pilots than to non-pilots. That’s because the effects of altitude hypoxia and CO poisoning are cumulative. For example, a COHb saturation of 10% (which is about what you’d get from chain-smoking cigarettes) would probably not be noticeable to someone on the ground. But at 10,000 feet, it could seriously degrade your night vision, judgment, and possibly cause a splitting headache.

After studying this hazard for many years and consulting with world-class aeromedical experts, I have come to the following conclusions:

  1. Every single-engine piston aircraft should carry a sensitive electronic CO detector.
  2. Any in-flight CO concentration above 10 ppm should be brought to the attention of an A&P for troubleshooting and resolution.
  3. Any in-flight CO concentration above 35 ppm should be grounds for going on supplemental oxygen (if available) and making a precautionary landing as soon as practicable.

Smokers are far more vulnerable to both altitude hypoxia and CO poisoning, since they’re already in a partially poisoned state when they first get into the aircraft. Because of COHb’s long half-life, you’d do well to abstain from smoking for 8 to 12 hours prior to flight.

Choosing a CO detector

Five CO detectors

Five CO detectors (left to right): chemical spot, UL-compliant residential (Kidde), non-UL-compliant (CO Experts 2015), industrial (BW Honeywell), TSO’d panel-mounted (CO Guardian 551).

Chemical spot detectors:Stay away from those ubiquitous el-cheapo adhesive-backed cardboard chemical spot detectors that are commonly sold by pilot shops and mail-order outfits for under trade names like “Dead Stop,” “Heads Up” and “Quantum Eye.” They have a very short useful life (about 30 days), and are extremely vulnerable to contamination from aromatic cleaners, solvents and other chemicals routinely used in aircraft maintenance.

These things often remain stuck on the instrument panel for years, providing a dangerous false sense of security. What’s worse, there’s no warning that the detector is outdated or has been contaminated—in some ways, that’s worse than not having a detector at all.

Even when fresh, chemical spot detectors are incapable of detecting low levels of CO. They’ll start turning color at 100ppm, but so slowly and subtly that you’ll never notice it. For all practical purposes, you’ll get no warning until concentrations rise to the 200 to 400 ppm range, by which time you’re likely to be too impaired to notice the color change.

Residential electronic detectors:Although battery-powered residential electronic detectors are vastly superior to those worthless chemical spots, most are designed to be compliant with Underwriter’s Laboratory specification UL-2034 (revised 1998). This spec requires that

(1)   The digital readout must not display any CO concentration less than 30 ppm.

(2)   The alarm will not sound until CO reaches 70 ppm and remains at or above that level for four hours.

(3)   Even at a concentration of 400 ppm, it may take as much as 15 minutes before the alarm sounds.

For aircraft use, you really want something much more sensitive and fast-acting. I like the non-UL-compliant CO Experts Model 2015 ($199 from It displays CO concentrations as low as 7 ppm and provides a loud audible alarm at concentrations above 25 ppm. It updates its display every 10 seconds (compared to once a minute for most residential detectors), which makes it quite useful as a “sniffer” for trying to figure out exactly where CO is entering the cabin.

Industrial electronic detectors:Industrial CO detectors cost between $400 and $1,000. A good choice for in-cockpit use is the BW Honeywell GasAlert Extreme CO  ($410 from This unit displays CO concentrations from 0 to 1,000 ppm on its digital display, has a very loud audible alarm with dual trigger levels (35 and 200 ppm).

Purpose-built aviation electronic detectors:Tucson-based CO Guardian LLC makes a family of TSO’d panel-mount electronic CO detectors specifically designed for cockpit use. These detectors detect and alarm at 50 ppm (after 10 minutes), or 70 ppm (after 5 minutes), and will alarm instantly if concentrations rise to 400 ppm. The digital display models ($599 and up) will show concentrations as low as 10 ppm. Available from Obviously, panel-mount detectors cannot be used as a sniffer to locate the source of a CO leak.

For more information…

There is an outstanding October 2009 research paper titled “Detection and Prevention of Carbon Monoxide Exposure in General Aviation Aircraft” authored by Wichita State University under sponsorship of the FAA Office of Research and Technology Development. The paper is 111 pages long, and discusses (among other things):

  • Characteristics of CO-related GA accidents
  • Evaluation of CO detectors, including specific makes and models
  • Placement of CO detectors in the cabin
  • Exhaust system maintenance and inspection

This research paper is available online at: