Transcontinent Love and War

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Middle aged guys are a sucker for a pretty face, as this odiferous saga proves.

I was headed overseas from New York to Paris, which is always a relatively painful transcontinental experience back in the Economy section. But my trouble started even before we left the gate.

I had selected an aisle seat near the rear of the aircraft. That is not my favorite choice, but it was all that was available on the flight.

There was a frankly gorgeous young woman sitting against the window, on my right. She had the slight scent of perfume about her. She looked up when I sat down, but didn’t speak. We exchanged smiles, and then settled in with no more immediate conversation.

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At this point, the Boeing 757 seating chart becomes relevant. I, illustrated as a red square, was seated in 35J. The young lady sitting next to me (illustrated by pink) was in 35K. As the plane took off, I settled in for a tiring but otherwise uneventful flight.

Once we reached an altitude where seatbelts could be undone, the girl next to me explained that  her boyfriend was a couple of rows back (marked by a blue square), and asked if I could change seats with him. Well, I am not one to impede young love, so I graciously agreed to move further back, from seat 35J to 37J. It was only two rows, I reasoned.

As I strapped in, feeling proud of myself for doing a good deed, I found myself seated next to a young Caucasian man, probably in his mid-twenties. We exchanged cordial glances. Although he seemed shyer than usual, to each his own, I thought. Perhaps he didn’t speak English.

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Within seconds of settling in, I detected a foul odor coming from the shy man in 37K (indicated by black) that, unlike the passing of gas, seemed to linger. I made sure the overhead vents were on full blast, but still the odor was inescapable. It was so pungent that I briefly thought it smelled like putrefaction, as if the man had a gangrenous leg hidden underneath his trousers. But the man did not appear to be in pain, and he clearly was not dead, yet, so my thinking, and revulsion, began to gravitate towards a horrific case of unchecked body odor. As one of my professors used to say, the smell was bad enough to gag a maggot.

I then realized I had been bamboozled by the cute girl in 35K who had taken advantage of this luckless middle-aged man. Once her boyfriend was seated where I had been just a few minutes before, I saw the two of them glancing  back at me, smiling. Yes, that couple in love had pulled off a coup on a gentleman, and this gentleman was now stuck flying through the night immersed in a suffocating stench that defied description.

There was another young lady, also lovely but lonely, sitting across the aisle from me. She kept looking longingly up the aisle, as if someone she knew was sitting there. Meanwhile, I was contemplating means of escaping the fetid odor overwhelming me. I considered shredding a paper towel from the lavatory, soaking it in airplane whiskey and thrusting those alcohol soaked tatters up my nose.

Now, I’ll admit I’m not a fan of whiskey. However, if it would somehow disguise the potentially lethal odor I was inhaling with each breath, it was an increasingly viable option. I had already ruled out the other alternatives, including accidentally throwing him out the passenger door. I’d heard those doors can’t be opened at altitude.

And then like a voice from heaven, the lovely girl across the aisle, in seat 37G, said the following: “Excuse me. My boyfriend is seated up there”, pointing to seat 34J. “Would you mind exchanging seats with him so we can sit close to each other?”

I could be mistaken, but I thought I heard a chorus of angels singing “Halleluiahs”.seating-change-2-circle

Of course I could not deny young love. So, within seconds I was sitting in seat 34J, one row forward from where I had started this flight, and breathing far less foul air.

A couple of hours later I headed to the back of the plane to find the lavatories. As I passed the young man who was seated in seat 37J, as his girl friend had requested, he gave me a mean look. But to be honest, as I passed him I simply thought, “All’s fair in love and war.”

In love and war, sometimes you just get lucky.

 

 

 

 

 

 

 

U.S. Navy Diving and Aviation Safety

Blood pressure is not the only silent medical killer. Hypoxia is also, and unlike chronically elevated blood pressure, it cripples within minutes, or seconds.

Hypoxia, a condition defined by lower than normal inspired oxygen levels, has killed divers during rebreather malfunctions, and it has killed pilots and passengers, as in the 1999 case of loss of cabin pressure in a Lear Jet that killed professional golfer Payne Stewart and his entourage and aircrew. Based on Air Traffic Control transcripts, that fatal decompression occurred somewhere between an altitude of 23,000 feet and 36,500 ft.

In most aircraft hypoxia incidents, onset is rapid, and no publically releasable record is left behind. The following recording is an exception, an audio recording of an hypoxia emergency during a Kalitta Air cargo flight.

Due to the seriousness of hypoxia in flight, military aircrew have to take recurrent hypoxia recognition training, often in a hypobaric (low pressure) chamber.

As the following video shows, hypoxia has the potential for quickly disabling you in the case of an airliner cabin depressurization.

Aircrew who must repeatedly take hypoxia recognition training are aware that such training comes with some element of risk. Rapid exposure to high altitude can produce painful and potentially dangerous decompression sickness (DCS) due to the formation of bubbles within the body’s blood vessels.

In a seminal Navy Experimental Diving Unit (NEDU) report published in 1991, LCDR Bruce Slobodnik, LCDR Marie Wallick and LCDR Jim Chimiak, M.D. noted that the incidence of decompression sickness in altitude chamber runs from 1986 through 1989 was 0.16%, including both aviation physiology trainees and medical attendants at the Naval Aerospace Medical Institute. Navy-wide the DCS incidence “for all students participating in aviation physiology training for 1988 was 0.15%”. If you were one of the 1 and a half students out of a thousand being treated for painful decompression sickness, you would treasure a way to receive the same hypoxia recognition training without risk of DCS.

With that in mind, and being aware of some preliminary studies (1-3), NEDU researchers performed a double blind study on twelve naïve subjects. A double-blind experimental design, where neither subject nor investigator knows which gas mixture is being provided for the test, is important in medical research to minimize investigator and subject bias. Slobodnik was a designated Naval Aerospace Physiologist, Wallick was a Navy Research Psychologist, and Chimiak was a Research Medical Officer. (Chimiak is currently the Medical Director at Divers Alert Network.)

Three hypoxic gas mixtures were tested (6.2% O2, 7.0% and 7.85% O2) for a planned total of 36 exposures. (Only 35 were completed due to non-test related problems in one subject.) Not surprisingly, average subject performance in a muscle-eye coordination test (two-dimensional compensatory tracking test) declined at the lower oxygen concentrations. [At the time of the testing (1990), the tracking test was a candidate for the Unified Triservice Cognitive Performance Assessment Battery (UTC-PAB)].

As a result of this 1990-1991 testing (4), NEDU proved a way of repeatedly inducing hypoxia without a vacuum chamber, and without the risk of DCS.

The Navy Aerospace Medical Research Laboratory built on that foundational research to build a device that safely produces hypoxia recognition training for aircrew. That device, a Reduced Oxygen Breathing Device is shown in this Navy photo.

070216-N-6247M-009 Whidbey Island, Wash. (Feb 16, 2007) Ð Lt. Cmdr. James McAllister, from San Diego, Calif. sits in the simulator during a test flight using the new Reduced Oxygen Breathing Device (ROBD). The ROBD is a portable device that delivers a mixture of air, nitrogen and oxygen to aircrew, simulating any desired altitude. Combined with a flight simulator the ultimate effect replicates an altitude induced hypoxia event. McAllister is the Director of the Aviation Survival Training Center at Whidbey Island. U.S. Navy photo by Mass Communication Specialist 1st Class Bruce McVicar (RELEASED)
Whidbey Island, Wash. (Feb 16, 2007) Lt. Cmdr. James McAllister, from San Diego, Calif. sits in the simulator during a test flight using the Reduced Oxygen Breathing Device (ROBD). The ROBD is a portable device that delivers a mixture of air, nitrogen and oxygen to aircrew, simulating any desired altitude. Combined with a flight simulator the ultimate effect replicates an altitude induced hypoxia event. McAllister is the Director of the Aviation Survival Training Center at Whidbey Island. U.S. Navy photo by Mass Communication Specialist 1st Class Bruce McVicar.

Although NEDU is best known for its pioneering work in deep sea and combat diving, it continues to provide support for the Air Force, Army and Marines in both altitude studies of life-saving equipment, and aircrew life support systems. Remarkably, the deepest diving complex in the world, certified for human occupancy, also has one of the highest altitude capabilities. It was certified to an altitude of 150,000 feet, and gets tested on occasion to altitudes near 100,000 feet. At 100,000 feet, there is only 1% of the oxygen available at sea level. Exposure to that altitude without a pressure suit and helmet would lead to almost instantaneous unconsciousness.

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A test run to over 90,000 feet simulated altitude.

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  1. Herron DM. Hypobaric training of flight personnel without compromising quality of life. AGARD Conference Proceedings No. 396, p. 47-1-47-7.
  2. Collins WE, Mertens HW. Age, alcohol, and simulated altitude: effects on performance and Breathalyzer scores. Aviat. Space Environ Med, 1988; 59:1026-33.
  3. Baumgardner FW, Ernsting J, Holden R, Storm WF. Responses to hypoxia imposed by two methods. Preprints of the 1980 Annual Scientific Meeting of the Aerospace Medical Association, Anaheim, CA, p: 123.
  4. Slobodnik B, Wallick MT, Chimiak, JM. Effectiveness of oxygen-nitrogen gas mixtures in inducing hypoxia at 1 ATA. Navy Experimental Diving Unit Technical Report 04-91, June 1981.

 

In the Claws of a Monster

By Huhu Uet (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
By Huhu Uet via Wikimedia Commons
Nature does not always provide good options. When faced with weather-related adversity, making the right decision can be as much a matter of luck as wisdom.

Homerville, Georgia is the home of some first-rate southern barbeque and home of one of the best genealogical libraries in the Southeast, the Huxford Geneological library. In June of 1975 I made an unintended stop at the Homerville Airport after flying my 1962 Cessna 150 from Thomasville, Georgia to Waycross, Georgia. My wife and Mother-In-Law were in Waycross, visiting, and on a Friday afternoon I took off in my 2-seater aircraft to meet my wife’s family 92 miles away.

As I approached Waycross a thunderstorm was directly on top of the field. The Waycross Fixed Base Operator confirmed they were being clobbered, so I made a 180 degree turn and flew 26 miles back to the Homerville airport that I had passed on the way in.

When I landed I found I was the only aircraft, and only human, on the field. But regrettably, there were no tie-downs, ropes or chains that I could use to secure the little Cessna while I found a phone to call my wife and tell her about the change in plans. The weather was good, and it should take only a few minutes to bother one of the nearby neighbors for a phone call. What could go wrong?

After I explained to my family where I was, I thanked the friendly lady who let me use her phone, and headed back to my aircraft. But as I approached the plane, the view at the other end of the runway was turning ugly. Another thunderstorm was headed straight for the field. And it was close, and mean-looking.

I climbed into the cockpit, started the engine, and sat there assessing what I was seeing out the windscreen. And thinking about options.

What I wanted to do was take-off and head for Waycross. I was not at all prepared to abandon my airplane and watch it be destroyed by the approaching storm. As I considered the fact that I would be taking off towards a thunderstorm, I thought of riding out the gusts on the ground, using the engine power and rudder to keep the plane pointed into the wind. But as I throttled the engine and rudder back and forth, reacting to the increasing gusts, I realized the 1000 pound plane would inevitably be picked up, with me in it, and dashed to the ground. It would not be a pretty sight, especially if it was lifted to a significant height by updrafts before being dropped.

The wind ahead of the thunderstorm rain shaft was picking up, gusting, and as I weighed the different options, the storm kept getting closer, closing my window of opportunity. As they say, the clock was ticking.

Finally, I decided I’d rather be airborne, in some semblance of control, than being airborne out of control. The storm was not yet on the field, but I knew I had scant seconds before the cloudy violence would make an escape impossible. I pressed hard on the brakes, dropped my flaps one notch, pushed the throttle full in, and when the engine was roaring as loudly as a 100 horse power engine can roar, I let go of the brakes and started my takeoff roll.

Thanks to the advantage of straight-down-the-runway storm winds, I lifted off very quickly. I stomped a rudder pedal and dipped a wing to turn as fast as I could away from the storm, passing over the roofs of nearby houses much closer than the residents were used to, I’m sure. But the plane was fully in control and headed quickly towards safety.

Although the storm winds were actually helping to push me away, I felt an occasional shudder from the back of the plane. I imagined the storm shaking me in its jowls, plucking at my wings with its sharp talons, as if angry that I had escaped its clutches.

I made it safely to Waycross, but my aircraft’s escape was short-lived.

If there were such a thing as a Storm Monster, I would think that it was malevolent, because exactly two weeks after that incident another thunderstorm hit the field in Waycross, where the plane was supposedly safely chained down. I was on the field as a vengeful storm snapped the steel chains holding down my plane’s tail, flipping the plane over on its back, crushing the tail. My little bird never had a chance.

I had risked my life in Homerville to avoid watching my beautiful bird be destroyed, only to see it destroyed in the same manner only a fortnight later.

We tell our children there are no monsters … but I’m not so sure.

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I Remember Nothing After the First Bounce

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From an album belonging to barnstormer Sergeant Carter G. Buton. Photo from latter half of the 1920s. Image found at San Diego Air & Space Museum Blog.

“It was a gorgeous day to jump from a perfectly good airplane. I, Mickey McGurn, was good at it, and I got paid well to do it.

But one day I got careless.

It was 1927, and parachute jumping was a new thing on the barnstorming circuit. It made people catch their breath when I jumped out of airplanes. They just knew they were going to see me fall straight to my death.

I would gather the parachute in my arms, without packing it, bundle it into the cockpit, and go aloft for a jump.

One day a number of my barnstorming friends protested at the way I handled the parachute. But I told them to mind their own business.

“Forget it,” I said. “I built this thing myself and I know what it’ll do.”

Well, I might have been wrong about that, because one day the ‘chute didn’t work. It opened only about a quarter of the way and I fell to the ground with a terrific speed. Those folks who were waiting to see me die almost got more than they bargained for.

Folks told me I bounced at least 10 feet into the air, but I don’t remember anything after I hit the ground.

The doctors said I broke pretty much every bone in my body, but obviously I lived, sort of.

I’m now hobbling around on crutches. I’m deaf, nearly blind, and can’t taste my food, or enjoy any of the things I used to.

My bones have healed, sort of, but not the way they were when I was a cocky young fool who felt invincible.

I guess I should have listened to my friends. They realized I was courting disaster, but I was too proud, or arrogant, or just plain stupid to notice it.

But they were right.

I suppose that no matter what you do, whether it’s racing cars, jumping out of airplanes, or walking on the bottom of the ocean, your friends are usually better at telling when you’re getting careless than you are.

I guess it’s similar to the way a friend can usually tell when you’re drunk before you can.

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The above is a fictional version of an actual accounting by one aviation daredevil named Mickey McGurn, given to a newspaper reporter for the Syracuse American. The short piece appeared in the Sunday edition under a section called the “World of Aviation”. The publication date was February 26, 1928. The writer was Gordon K. Hood, a feature writer who penned several aviation-themed chapters for the paper, a collection of mini-stories such as this one, collectively called “Sprouting Wings”. Mr. Hood was himself quite an accomplished early aviation pioneer, as recounted in a 1939 edition of the Syracuse Journal.

I have taken the time to paraphrase this story due to its applicability to many potentially hazardous endeavors. Safety risks are not always noticeable to those at greatest risk.

The actual article is found below. It, and a full page copy of the 1928 newspaper page, was provided to the present author by Mr. Douglas Barnard, presently from Waldorf, Maryland.

1928

 

After the Heart Attack – The Healing Power of Athletic Passions

DSC06084-B2There is nothing quite like a heart attack and triple bypass surgery to get your attention.

Even if you’ve been good, don’t smoke, don’t eat to excess, and get a little exercise, it may not be enough to keep a heart attack from interrupting your life style, and maybe even your life.

Post-surgical recovery can be slow and painful, but if you have an avocational passion, that passion can be motivational during the recovery period after a heart attack. There is something about the burning desire to return to diving, flying, or golfing to force you out of the house to tone your muscles and get the blood flowing again.

My return to the path of my passions, diving and flying, began with diet and exercise. My loving spouse suggested a diet of twigs and leaves, so it seemed. I can best compare it to the diet that those seeking to aspire to a perpetual state of Buddha-hood, use to prepare themselves for their spiritual end-stage: it’s a state that looks a lot like self-mummification. Apparently those fellows end up either very spiritual or very dead, but I’m not really sure how one can tell the difference.

The exercise routine began slowly and carefully: walking slowly down the street carrying a red heart-shaped pillow (made by little lady volunteers in the local area just for us heart surgery patients). The idea, apparently, is that if you felt that at any point during your slow walk your heart was threatening to extract itself from your freshly opened chest, or to extrude itself like an amoeba between the stainless steel sutures holding the two halves of your rib cage together, that pillow would save you. You simply press it with all the strength your weakened body has to offer against the failing portion of your violated chest, and that pressure would keep your heart, somehow, magically, in its proper anatomical location.

I am skeptical about that method of medical intervention, but fortunately I never had occasion to use it for its avowed purpose.

Eventually I felt confident enough to ditch the pillow and pick up the pace of my walks. In fact, I soon found I could run again, in short spurts. It was those short runs that scared the daylight out of my wife, but brought me an immense amount of pleasure.  It meant that I might be able to regain my flying and diving qualifications.

Three months later I was in the high Arctic with good exercise capability, and most importantly the ability to sprint, just in case the local polar bears became too aggressive on my nighttime walks back from the only Ny-Alesund pub.

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Stress test, Public Domain, from Wikimedia Commons.

After that teaching adventure, I prepared myself for the grinder that the FAA was about to put me through: a stress test. Not just any stress test mind you, but a nuclear stress test where you get on a treadmill and let nurses punish your body for a seeming eternity. Now, these nurses are as kindly as can be, but they might well be the last people you see on this Earth since there is a small risk of inducing yet another heart attack during the stress test. Every few minutes the slope and speed of the treadmill is increased, and when you think you can barely survive for another minute, they inject the radioisotope (technetium 99m).

With luck, you would have guessed correctly and you are able to push yourself for another long 60-seconds. I’m not sure exactly what would happen if you guess incorrectly, but I’m sure it’s not a good thing.

And then they give you a chance to lie down, perfectly still, while a moving radioisotope scanner searches your body for gamma rays, indicating where your isotope-laden blood is flowing. With luck, the black hole that indicates dead portions of the heart will be small enough to be ignored by certifying medical authorities. (An interesting side effect of the nuclear stress test is that you are radioactive for a while, which in my case caused a fair amount of excitement at large airports. But that’s another story.)

The reward for all the time and effort spent on the fabled road to recovery, is when you receive, in my case at least, the piece of paper from the FAA certifying that you are cleared to once again fly airplanes and carry passengers. With that paper, and having endured the test of a life-time, I knew that I’d pass most any diving physical.

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Vortex Springs, 2010

Having been in a situation where nature dealt me a low blow and put my life at risk and, perhaps more importantly, deprived me of the activities that brought joy to my life, it was immensely satisfying to be able to once again cruise above the clouds on my own, or to blow bubbles with the fish, in their environment. Is there anything more precious that being able to do something joyful that had once been denied?

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A goofy looking but very happy diver sharing a dive with his Granddaughter, July 2014.

 

 

 

 

 

 

 

 

 

 

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Without a doubt, the reason I was able to resume my passions was because I happened to do, as the physicians said, “all the right things” when I first suspected something unusual was happening in my chest. The symptoms were not incapacitating so I considered driving myself to the hospital. But after feeling not quite right while brushing my teeth, I lay down and called 911. The ambulance came, did an EKG/ECG, and called in the MI (myocardial infarction) based on the EKG. The Emergency room was waiting for me, and even though it was New Years’ eve, they immediately called in the cardiac catheterization team. When the incapacitating event did later occur I was already in cardiac ICU and the team was able to act within a minute to correct the worsening situation.

Had I dismissed the initial subtle symptoms and not gone to the hospital, I would not have survived the sudden onset secondary cardiac event.

The lesson is, when things seem “not quite right” with your body, do not hesitate. Call an ambulance immediately and let the medical professionals sort out what is happening. That will maximize your chances for a full and rapid recovery, and increase the odds of your maintaining your quality of life.

It will also make you appreciate that quality of life more than you had before. I guarantee it.

Redundancy – a Life Saver in Diving and Aviation

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Photo taken from the author’s aircraft one stormy Florida Panhandle morning. (click to enlarge)

I was recently flying a private aircraft down the Florida Peninsula to Ft. Lauderdale to give a presentation on diving safety. As I continually checked the cockpit instruments, radios and navigation devices, it occurred to me that the redundancy that I insist upon in my aircraft could benefit divers as well.

In technical and saturation diving, making a free ascent to the surface is just as dangerous as making a free descent to the ground in an airplane, at night, in the clouds. In both aviation and diving, adequate redundancy in equipment and procedures just might make life-threatening emergencies a thing of the past.

Aviation

As I took inventory of the redundancy in my simple single engine, retractable gear Piper, I found the following power plant redundancies: dual ignitions systems, including dual magnetos each feeding their own set of spark plug wires and redundant spark plugs (two per cylinder). There are two sources of air for the fuel-injected 200 hp engine.

There are two ways to lower the landing gear, and both alarms and automatic systems for minimizing the odds of pilot error — landing with wheels up instead of down. (I’ve already posted about how concerning that prospect can be.)

I also counted three independent sources of weather information, including lightning detection, and two powerful communication  radios and one handheld backup radio. For navigation there is a compass and four electronic navigation devices: one instrument approach (in the clouds) approved panel mount GPS with separate panel-mounted indicator, an independent panel mounted approach certified navigation radio, plus two portable GPS with moving map displays and superimposed weather. Even the portable radio has the ability to perform simple navigation.

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There’s two of just about everything in this Arrow panel.

The primary aircraft control gyro, the artificial horizon or attitude indicator, also has a fully independent backup. One gyro operates off the engine-powered vacuum pump, and the second gyro horizon is electrically driven. Although by no means ideal, the portable GPS devices also provide attitude indicators based upon GPS signals. In a pinch in the clouds, it’s far better than nothing. Of course, even if all else fails, the plane can still be flown by primary instruments like rate of climb, altimeter, and compass.

There is only one sensitive altimeter, but two GPS devices also provide approximate altitude based on GPS satellite information.

Diving

But what about divers? How are we set for redundancy?

Starting with scuba (self-contained underwater breathing apparatus), gas supplies are like the fuel tanks in an aircraft. I typically dive with one gas bottle, but diving with two or more bottles is common, especially in technical diving. In a similar fashion, most small general aviation aircraft have at least two independent fuel tanks, one in each wing.

The scuba’s engine is the first stage regulator, the machine that converts high pressure air into lower pressure air. Most scuba operations depend on one of those “engines”, but in extreme diving, such as low temperature diving, redundant engines can be a life saver. While most divers carry dual second stage regulators attached to a single first stage, for better redundancy polar divers carry two independent first stages and second stages. Two first stage regulators can be placed on a single tank.

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An H-valve for a single scuba bottle. Two independent regulators can be attached.
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A Y-valve for Antarctic diving with two independent scuba regulators attached.

 

 

 

 

 

 

 

 

 

 

 

 

Even then, I’ve witnessed dual regulator failures under thick Antarctic ice. The only thing saving that very experienced diver was a nearby buddy diver with his own redundant system.

There is a lot to be gained by protecting the face in cold water by using a full face mask. But should the primary first or second stage regulator freeze or free flow, the diver would normally have to remove the full face mask to place the second regulator in his mouth.

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Two regulators, one full face mask. Photo courtesy of Michael Lang and Scuba Pro.

Reportedly, sudden exposure of the face to cold water can cause abnormal heart rhythms, an exceedingly rare but potentially dangerous event in diving. If the backup or bail out regulator could be incorporated into the full face mask, that problem would be eliminated. The photo on the right shows one such implementation of that idea.

 

Inner Space 2014_Divetech _Nikki Smith_Rosemary E Lunn__Roz Lunn_The Underwater Marketing Company_Nancy Easterbrook_rebreather diving_2014-05-27 22.30.47
Nikki Smith, rebreather diver with open circuit bailout in her right hand. Photo courtesy of Rosemary E Lunn (Roz), The Underwater Marketing Company.

Rebreathers are a different matter. Most rebreather divers carry a bailout system in case their primary rebreather fails or floods. For most technical divers, that redundancy is an open circuit regulator and bailout bottle. However, there are options for the bail-out to be an independent, and perhaps small rebreather. (One option for a bail-out semiclosed rebreather is found here.) Such a bail-out plan should provide greater duration than open-circuit bailout, especially if the divers are deep when they go “off the loop”.

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U.S. Navy photo by Bernie Campoli.

For some military rebreather divers, there is at least one complete closed-circuit rebreather available where a diver can reach it in case of a rebreather flood-out.

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A commercial saturation diver with semi-closed rebreather backpack as emergency bail-out gas.

For deep sea helmet diving, the bail-out rebreather is on their back and a simple valve twist will remove the diver from umbilical-supplied helmet gas to fresh rebreather gas.

The most common worry for electronically controlled rebreather divers is failure of the rig’s oxygen sensors. For that reason it is common for rebreathers to carry three oxygen sensors. Unfortunately, as the Navy and others have noted, triple redundancy really isn’t. Electronic rebreathers are largely computer controlled, and computer algorithms can allow the oxygen controller to become confused, resulting in oxygen control using bad sensors, and ignoring a correctly functioning oxygen sensor.

The U.S. Navy has performed more than one diving accident investigation where that occurred. Safety in this case can be improved by adding an independent, redundant sensor, by improving sensor voting algorithms, by better maintenance, or by methods for testing all oxygen sensors throughout a dive.

In summary, safe divers and safe pilots are always asking themselves, “What would I do if something bad happens right now?” Unfortunately, private pilots and divers quickly discover that redundancy is not cheap. However, long ago I decided that if something unexpected happened during a flight or a dive, I wouldn’t want my last thoughts to be, “If only I’d spent a little more money on redundant systems, I wouldn’t be running out of time.”

Time, like fuel and breathing air, is a commodity you can only buy before you run out of it.

Separator smallDisclaimer: This blog post is not an endorsement of any diving product. Diving products shown or mentioned merely serve as examples of redundancy, and are mentioned only to further diver safety. A search of the internet by interested readers will reveal a panoply of alternative and equally capable products to enhance diver safety.

Root Causes: Some Accidents Are No Accident

Interesting flights and interesting dives provide an opportunity for post-event introspection; debriefing if you will.

Professionally, I am called upon to analyze fatalities and near-misses for the Navy and, occasionally, the Air Force. Personally, I spend even more time analyzing “what ifs” for my own activities.

For example, recently I was preparing a video of one of my more beautiful nighttime flights with a passenger, departing the coal-mining regions of Pennsylvania, heading south over the valleys and mountains of Appalachia as the early morning sun began to brighten our part of the world. Sunrise crop Editing that video gave me a chance to reflect on the pre-flight and in-flight decisions I made that day. There were many decisions to be made, and those decisions resulted in not only a safe flight, but a spectacular flight.

But like most things, there was also a risk, calculated, and weighted, and recalculated as conditions in flight and on the ground changed in the face of aggressive weather.

In very real ways, single pilot IFR (instrument flight rules) flight is akin to cave diving. They are both technically challenging, rewarding solo activities. However, you better be on your game, or else not play.

I was cave diving before cave diving was cool; before it was considered a technical diving specialty, before safety rules and high quality equipment was available. Trimix, scooters, and staged decompression were all decades in the future, and frankly the safety record at that time was atrocious. I am alive because I had the good sense to limit my penetration; “just a little” was enough of a sobering experience, about which I have previously written.

But this posting is not about moderation; it is a warning to those who would, for whatever reason, deliberately make bad decisions, one after the other. If after a chain of such deliberate misadventures, a fatality results, then I would say that fatality is no accident. It is a procedure; a flawed process of decision making with a more or less guaranteed fatal outcome.

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Dr. Tom Iliffe, Texas A&M University at Galveston

Lest you lose interest in reading this post because you believe all cave divers are loonies, rest assured that could not be further from the truth. Where I work we have four very active cave divers, highly intelligent, experienced, diving deep breathing trimix (helium/nitrogen/oxygen) when necessary using scuba and rebreathers. They are safe divers who are on the cutting edge of diving research when they’re not diving for pleasure. In fact, two of them are the U.S Navy’s diving accident investigators, so they know all too well about underwater misadventures.

Friends met early in my career have been the cave explorers of the 70’s and 80’s; names you may know like Bill Gavin and John Zumrick. Another long-time friend from the Navy’s Scientist in the Sea Program, and of whom I am quite envious, is Dr. Tom Iliffe, a biologist constantly on the front edge of underwater cave biology. (My draft novel, Children of the Middle Waters, includes a story about his beloved Remipedes.)

All these cave divers have survived due to their sane and balanced approach to risk management; moderation in all things. But sadly, not all divers I’ve come to know, one way or the other, have been so sensible and measured.

One was a wonderfully gracious man, a Navy diver who had a hobby: free diving. He’d tell me how he enjoyed surprising divers in the main cave at Morrison Springs, Florida when he would swim up to them and wave, while wearing no breathing equipment at all except that with which he was born.

I’m sure they were shocked; I know I would be.

After a while, as he gained experience with this solo recreation, he began to confide in me, and ask me questions about events he’d experienced. He told me how pleasant it was sometimes when he would surface. I warned him about shallow water blackout, loss of consciousness on ascent, and explained the physical laws that made breath-hold diving so dangerous; at least in the manner in which he practiced it.

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Morrison Springs, Florida. Photo licensed under Wikimedia Commons.

The last day I saw him alive, he once again came in for consultation, and told me about the euphoria he had experienced a few days before. I was of course extremely concerned and told him that what he described sounded like a near death experience. The next time he might not be lucky enough to survive, I told him. Later I heard more of that story; the previous weekend he had been found floating unconscious on the surface, but was revived.

Soon after that, this diver was again found, but this time his dive had proven fatal. His personal agenda for thrills exceeded all bounds of either training or common sense. And those thrills killed him.

The only solace I could find was that he wanted to share his experience and bravado, but he clearly was not interested in really hearing the truth, no matter how hard I worked to educate and dissuade him. While some might call this young man’s mental status as a perpetual death wish, I would argue that he never consciously thought he would die; at least not that way. Life was good, in his perspective, and I suspect he thought he was smart enough to make sure it continued that way.

Unfortunately when we were talking, we did not know just how close the end was.

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Jackson Blue Spring, Marianna, Florida. Photo by Paul Clark, released under Creative Commons license.

The same was true I suspect for another well-liked diver who was the subject of a fatality report I helped write several years later. It was a rebreather fatality at Jackson Blue Spring in Marianna, Florida. The decedent was reportedly an experienced diver. I won’t belabor the story because the NEDU report is available on the internet (released by his family and available on the Rebreather Forum).

Nevertheless, the sequence of events leading to his demise involved a surprisingly long list of decision points which should have prevented the fatal dive from occurring. As each opportunity to change the course of events was reached, poor choices were made. In combination those choices led inexorably to his demise.

By now we know that even the U.S. Navy is not immune to poor decision trees. In fact, I would argue that wishful thinking is a common factor among people with intelligence and technical ability, and those with a “get it done” attitude. People who fix problems for a living are seemingly resistant to admitting that sometimes the bridge really is too far, and some problems are better fixed in the shop than in the field.

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Gareth Lock of Cranfield University, Bedfordshire, U.K. is currently collecting data on diving incidents through a questionnaire on “The Role of Human Factors in SCUBA Diving Incidents and Accidents”. Like me, he has both an aviation and diving background. Gareth is serious about trying to understand and reduce diving accidents. Links to a description of his work, and his questionnaire can be found here and here. If you are a diver, please consider contributing much needed information.

The Patients, the Pilot, and the Politicians

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A Beechcraft Baron similar to the one used by Quest Diagnostics. (From Wikimedia Commons).

Every night a pilot from Atlanta makes a round-robin cargo flight to Albany GA and Dothan AL, then continues down to the coast to load cargo from Panama City FL, Pensacola, and Mobile AL before returning home. He used to fly a single engine Beech Bonanza, but now pilots a Baron, a twin-engine, 190 kt fast mover.

On really rough weather nights I’ve watched vicariously through FlightAware.com as he scurries away from lethal skies and diverts to any safe harbor. His cargo is your lifeblood, literally, but it’s not worth dying for.

He makes that flight each night because during the day in each of those cities patients had blood drawn at their doctor’s office. The samples that will tell the doctor the life and death stories of the day’s patients are whisked away to a large laboratory near Atlanta for processing overnight.

After taking off from Gwinnett County Airport near Lawrenceville, GA at 6 PM or so, the solitary pilot returns to his home base about midnight.

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A Centurion 210; not your ordinary Cessna.

I was alerted one night that a plane I’d flown to Houston and back, a Cessna Centurion 210, had a gear collapse at the local Panama City Airport. I knew the plane well.

Unfortunately, shortly after the only runway was closed the Quest Diagnostics Baron approached the area, attempting to land. I turned on my aviation radio and heard the “850”, as it’s called, being told to hold, circling, while airfield crews attempted to move the damaged Centurion off the runway.

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The original two-runway Panama City Airport, circa 2007. (Click to enlarge)

And that’s where the politicians come in.

Local Panama City politicians felt obliged to close down the Panama City airport with two runways (formerly known as PFN) and relocate to a larger facility, again with two runways. The new two runway airport, KECP, looked great in an artist’s rendition.

But artists don’t build airports. The reason why the second runway was not built is not a subject for this blog posting. What is the subject, is that promises made to the citizens of Panama City were not promises kept. And on that night as “850” circled overhead, there would be real consequences for the political decisions which had been made.

Once construction began on the main 10,000 ft long runway at the donated site, all mention of the second runway was forgotten; not by the local pilots, but by the local politicians and the land company.

Second runways serve important purposes. They are usually called “cross-wind” runways. I’ve landed many times on the cross-wind runway at PFN, and I’ve also been on Delta flights that used that runway when the wind across the main runway was dangerously high.

Cross-wind runways are not only a safety factor for overbearing wind conditions, but also provide an alternate landing site in case the main-runway is closed due to an aircraft being stuck on the runway.

That night as “850” was trying to land to pick up the day’s tissue samples from the Panama City area, the main runway was closed by the broken Centurion, and there was no backup runway. The pilot circled Panama City until his fuel became critical, and then he flew on to his next  stop in Pensacola.

So all the blood drawn from patients in the Panama City area that day missed the trip to the Quest Diagnostics laboratory, due to a promise made but not kept.

But I suppose that is hardly news. Rather, it appears to be deeply woven into the very fabric of politics.

 

 

 

 

 

 

I Too Landed at the Wrong Airport

As a professional in underwater diving, and an amateur airman, I’ve been thinking a lot lately about the causes of accidents and “near-misses”. If you’re reading this in early 2014, you are no doubt aware of several recent incidents of commercial and military jets landing at the wrong airport. In the latest case there was a potential for massive casualties, but disaster was averted at the last possible moment.

As they say, to err is human. From my own experience, I know the truth of that adage in science, medicine, diving, and the subject of this posting, aviation. Pilot errors catch everyone’s attention because we, the public, know that such errors could personally inconvenience us, or worse. But lesser known are the sometimes subtle factors that cause human error.

I can honestly tell you  exactly what I was doing and thinking that caused errors at the very end of long flights. Those errors, none of which were particularly dangerous or newsworthy, were nonetheless caused by the same elements that have been discovered in numerous fatal accidents. Namely, what I was seeing, was not at all what I thought I was seeing.

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The small but capable Cessna 150B.

Long before the advent of GPS navigation, cell phones and electronic charts,  I was flying myself and an Army friend (we had both been in Army ROTC at Georgia Tech) from Aberdeen Proving Ground, MD to Georgia. I was dropping him off in Atlanta at Peachtree-Dekalb Airport, and then I would fly down to Thomasville in Southwest Georgia where my young wife awaited me.

Since it was February most of the planned six hour flight was at night. We couldn’t take-off until we both got off duty on a Friday.

I had planned the flight meticulously, but I had not counted on the fuel pumps being shut down at our first planned refueling spot. After chatting with some local aviators about the closest source of fuel, we took off on a detour to an airport some thirty miles distant. That unplanned detour was stressful, as I was not entirely sure we’d find fuel when we arrived. Fortunately, we were able to tank up, and continue on our slow journey. We were flying in my 2-seat Cessna 150, and traveling no faster than about 120 mph, so the trip to Atlanta was a fatiguing and dark flight.

As we eventually neared Atlanta, I was reading the blue, yellow and green paper sectional charts under the glow of red light from the overhead cabin lamp. Lights of the Peachtree-Dekalb airport were seemingly close at hand, surrounded by a growing multitude of other city lights. Happy that I was finally reaching Atlanta, I called the tower and got no answer. No matter, it was late, and many towers shut down operations  fairly early, about 10 PM or so. So I announced my position and intentions, and landed.

The runway was in the orientation I had expected, and my approach to landing was just as I had planned. However, as I taxied off the runway, I realized the runway environment was not as complex as it should have been. We taxied back and forth for awhile trying to sort things out, before I realized I’d landed 18 nautical miles short of my planned destination.

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My unplanned refueling stop in South Carolina placed me far enough off course to take me directly over an airport that looked at night like my destination, Peachtree-Dekalb, Atlanta. (Solid line: original course, dashed line: altered course.)

I had so much wanted that airport to be PDK, but in my weariness I had missed the signs that it was not. I had landed at Gwinnett County Airport, not Peachtree-Dekalb.

No harm was done, but my flight to Thomasville was seriously delayed by the two extra airport stops. It was after 1 AM before I was safe at the Thomasville, GA airport, calling my worried wife to pick me up.

She was not a happy young wife.

A few years later, I added an instrument ticket to  my aviation credentials, and thought that the folly of my youth was far behind me. Now, advance quite a few decades, to a well-equipped, modern cross-country traveling machine, a Piper Arrow with redundant GPS navigation and on-board weather. I often fly in weather, and confidently descend through clouds to a waiting runway. So what could go wrong?

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Piper Arrow 200B at home in Panama City, Fl.

Wrong no. 2 happened when approaching Baltimore-Washington International airport after flying with passengers from the Florida Panhandle. Air Traffic Control was keeping me pretty far from the field as we circled Baltimore to approach from the west. I had my instrumentation set-up for an approach to the assigned runway, but after I saw a runway, big and bold in the distance, I was cleared to land, and no longer relied on the GPS as I turned final.

As luck would have it, just a minute before that final turn we saw President George W. Bush and his decoy helicopters flying in loose formation off our port side. I might have been a little distracted.

In the city haze it had been hard to see the smaller runway pointing in the same direction as the main runway. So I was lining up with the easy-to-see large runway, almost a mile away from where I should have been. It was the same airport of course, but the wrong parallel runway.

I was no doubt tired, and somewhat hurried by the high traffic flow coming into a major hub for Baltimore and Washington. Having seen what I wanted to see, a large runway pointed in the correct direction, I assumed it was the right one, and stopped referring to the GPS and ILS (Instrument Landing System) navigation which would have revealed my error.

The tower controller had apparently seen that error many times before and gently nudged me verbally back on course. The flight path was easily corrected and no harm done. But I had proven to myself once again that at the end of a long trip, you tend to see what you want to see.

Several years later I had been slogging through lots of cloud en-route to Dayton, Ohio. I had meetings to attend at Wright Patterson Air Force base. It was again a long flight, but I was relaxed and enjoying the scenery as I navigated with confidence via redundant GPS (three systems operating at the same time).

As I was approaching Dayton, Dayton Approach was vectoring me toward the field. They did a great job I thought as they set me up perfectly for the left downwind at the landing airport. But then I became a bit perturbed that they had vectored me almost on top of the airport and then apparently forgotten about me. So I let them know that I had the airport very much in sight. They switched me to tower, and I was given clearance to land.

As I began descending for a more normal pattern altitude, the Dayton Tower called and said I seemed to be maneuvering for the wrong airport. In fact, I was on top of Wright Patterson Airbase, not Dayton International.

Rats! Not again.

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Wish my electronic Foreflight chart on my iPad had these sorts of markings.

Well, the field was certainly large enough, but once again I had locked eyes on what seemed to be the landing destination, and in fact was being directed there by the authority of the airways, Air Traffic Control (ATC). And so I was convinced during a busy phase of flight that I was doing what I should have been doing, flying visually with great care and attention. However, I was so busy that my mind had tunnel vision. I had once again not double checked the GPS navigator to see that I was being vectored to a large landmark which happened to lie on the circuitous path to the landing airport. (I wish they’d told me that, but detailed explanations are rarely given over busy airwaves.)

Oddly enough, if I had been in the clouds making an instrument approach, these mind-bending errors could not have happened. But when flight conditions are visual, the mind can easily pick a target that meets many of the correct criteria like direction and proximity, and then fill in the blanks with what it expects to see. In other words, it is easy in the visual environment to focus with laser beam precision on the wrong target. With all the situational awareness tools at my disposal, they were of no use once my brain made the transition outside the cockpit.

To be fair, distracting your gaze from the outside world to check internal navigation once you’re in a critical visual phase of approach and landing can be dangerous. That’s why it’s good to have more than one pilot in the cockpit. But my cockpit crew that day was me, myself and I; in that respect I was handicapped.

Apparently, even multiple crew members in military and commercial airliners are occasionally lulled into the same trap. At least that’s what the newspaper headlines say.

My failings are in some ways eerily similar to reports from military and commercial incidents. Contributing factors in the above incidents are darkness, fatigue, and distraction. When all three of these factors are combined, the last factor that can cause the entire house of cards, and airplane, to come tumbling down, is the brain’s ability to morph reality into an image which the mind expects to see. Our ability to discern truth from fiction is not all that clear when encountering new and unexpected events and environments.

The saving grace that aviation has going for it is generally reliable communication. ATC saved me from major embarrassment on two of these three occasions.

I only wish that diving had as reliable a means for detecting and avoiding errors.

 

 

 

 

 

 

 

 

 

 

 

The Aesthetics of Flying in Clouds

When it comes to vocations and avocations, I know of none more aesthetically pleasing than flying and diving. I’m sure there are many others, but I simply don’t know them.

My vocation is diving, and flying is my avocation. I also know commercial pilots who dive in caves simply for the joy of diving. Those two activities, flying and diving, are fairly similar, as I’ve noted before.

There are experiences in flying and diving that make them more than enjoyable. They are actually breathtaking, when one takes the time to appreciate them.

For me, the breath taking part is flying into and out of clouds; what is called instrument flying. It’s called that because when you’re in clouds you can’t see the horizon, and you can’t trust bodily sensations, so you are entirely dependent upon your aircraft instruments to make sure you, your passengers, and the aircraft, do not come to harm.

Granted, there are times during an instrument flight when you see absolutely nothing outside the aircraft. Some have compared it to flying inside a milk bottle, which is in my opinion an apt analogy. If it happens to be smooth flight, then there is no sensation of flight at all. The electronic equipment counts down the miles, but as far as you can tell you are in aerial limbo, seemingly suspended in time and space, encroaching on the edges of the twilight zone. 

But when you eventually break out of those clouds, you instantaneously switch from sensory deprivation to sensory overload. The view can be spectacular. 

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When I was an instrument student, long before GPS navigation, instrument flying was hard work, especially when training. It still is in many ways, but technology has made flight in the clouds more precise, and frankly easier over all than it used to be.

But in the clouds a pilot is still too busy “aviating, navigating, and communicating”, to catch more than a brief glance outside, to enjoy the ever shifting textures of white clouds, blue sky and a multitude of grays in between. Occasionally you spy greens and browns of the ground, seen fleetingly through breaks in the cloud cover.

It is a grand theater in the sky not visible from the ground. For that reason, it is special, and to be seen in that moment and that place by no one else in the world except you and your passengers.

The video below gives a sample of such variable flows of scenery, with visibility ranging from zero to miles. The entire flight looped around my home airport in Panama City, FL, as I was radar vectored along a large rectangle, eventually joining a course bringing the aircraft back to a straight-in approach for landing.

This particular flight was a currentcy flight, so the departure and approach to landing was repeated several times. The video, however, ends just after I set up the navigation devices for the next approach. (I suggest you watch the video full screen at the highest resolution possible – 1440p HD.)

The only way I can hope to describe the beauty of such a flight is through the music which accompanies it. The quietness, the excitement, is all there. And from one who has experienced all those emotions during the flight, I can attest to the relevance of that music.